Engineering T ;i^^^^ FIRE TESTS of BUILDING COLUMNS by ASSOCIATED FACTORY MUTUAL FIRE INSURANCE COMPANIES THE NATIONAL BOARD OF FIRE UNDERWRITERS and the BUREAU OF STANDARDS, DEPARTMENT OF COMMERCE An Experimental Investigation of the Resistance of Columns, Loaded and Exposed to Fire or to Fire and Water, with Record of Characteristic Effects Jointly Conducted at UNDERWRITERS' LABORATORIES Chicago, Illinois 1917-1919 Library Engineering Library ADDITIONAL COPIES OF THIS PUBLICATION MAY BE PROCURED FROM THE FOLLOWING AT $2.00 PER COPY PAPER COVER $2.50 PER COPY CLOTH COVER Associated Factory Mutual Fire Insurance Companies, 31 Milk Street, Boston, Mass. Underwriters' Laboratories 207 East Ohio Street, Chicago, Illinois 800,328 FIRE TESTS OF BUILDING COLUMNS CONTENTS By the method of presentation that follows, Section I gives a general outline of the tests; Sections II, III and IV give descriptions of the columns, column coverings and methods used in their preparation ; Section V and Appendix D, results of auxiliary tests of materi- als ; Sections VI, VII, VIII and IX, descriptions of apparatus and method of testing; Sections X and XI and Appendices A, B and C, results of tests; Sections XII and XIII, discussion of test data and conclusions The full presentation of the results of the present investiga- tion is necessarily of considerable extent, and familiarity with the general plan will be a material aid in reading, and if desired, in selecting for particular attention such portions as may best serve the reader's immediate purpose. Page I. INTRODUCTION . 15 1. Purpose 15 2. Scope of Tests 16 3. Acknowledgment 17 II. DESCRIPTION OF COLUMNS 19 1. Structural Steel Columns 19 (a) Details of Design 19 (b) Bearings .- 19 (c) Riveting , 19 (d) Initial Straightness 19 (e) Properties of Sections 24 2. Cast Iron Columns 26 (a) Details of Design and Manufacture 26 (b) Bearings '. 26 (c) Initial Straightness 26 (d) Variations in Metal Thickness 26 3. Pipe Columns 29 (a) Details of Design and Manufacture 29 (b) Bearings 29 4. Reinforced Concrete Columns 29 (a) Details of Design 29 (b) Bearings and End Restraint : 32 5 6 FIRE TESTS OF BUILDING COLUMNS Page II. DESCRIPTION OF COLUMNS Continued. 5. Timber Columns 32 (a) Species of Timber 32 Ob) Cap and Bearing Details 32 (c) Properties of the Timber 32 III SCHEDULE OF TESTS 35 1. General Considerations . . . 35 (a) Object and Limitations 35 Ob) Preliminary Work on Schedule 35 2. Schedule of Fire Tests 36 (a) Unprotected Columns 36 (b) Partly Protected Columns 41 (c) Columns Protected by Plaster on Metal Lath 41 (d) Columns Protected by Concrete. 42 (e) Columns Protected by Hollow Clay Tile 46 (f ) Columns Protected by Gypsum Block 50 (g) Columns Protected by Brick 52 (h) Reinforced Concrete Columns 53 (i) Timber Columns 54 3. Schedule of Fire and Water Tests 55 (a) Columns Protected by Concrete 55 (b) Columns Protected by Hollow Clay Tile 55 (c) Columns Protected by Gypsum Block 55 (d) Plaster on Metal Lath Protection 55 (e) Reinforced Concrete Columns 55 ( f ) Unprotected Cast Iron Columns 55 [V. - PLACING OF COVERINGS AND CONCRETE COLUMNS 61 1. Concrete Protections and Columns , 61 (a) Forms and Staging 61 (b) Method of Proportioning 61 (c) Mixing and Placing 61 2. Plaster on Metal Lath Protections 63 (a) Placing of Lath 63 (b) Applying the Plaster 63 3. Hollow Clay Tile and Brick Protections 65 (a) Proportioning of Mortar 65 (b) Placing of Tile and Brick 65 (c) Placing of Concrete Filling 65 4. Gypsum Block Protections 65 (a) Proportioning of Mortar 65 (b) Placing of Block 65 (c) Placing of Filling 65 5. Method of Storage 66 V. AUXILIARY TESTS OF MATERIALS 67 1. Tests of Structural, Bar and Wire Steel 67 2. Tests of Cast Iron 68 3. Tests of Portland Cement 69 4. Tests of Sand '. 69 5. Tests of Coarse Concrete Aggregates 70 6. Source and Classification of Concrete Aggregates 70 7. Tests of Concrete 72 (a) Test Specimens , 73 (b) Percent Water in Concrete Mixture 74 (c) Testing of Concrete Cylinders 74 (d) Compressive Strength of Concrete 74 (e) Modulus of Elasticity of Concrete 78 CONTENTS 7 Page V. AUXILIARY TESTS OF MATERIALS Continued. 8. Tests of Lime 80 . 9. Tests of Calcined Gypsum 80 10. Tests of Mortar, Plaster and Filling 80 11. Tests of Hollow Clay Tile 81 (a) Classification and Description 81 (b) Porosity and Absorption 81 (c) Compressive and Transverse Strength 82 (d) Temperatures of Vitrification and Fusion 82 12. Tests of Brick 82 13. Tests of Gypsum Block 83 14. Transverse Strength of Gypsum Wall Board 83 VI. DESCRIPTION OF FURNACE AND RELATED EQUIPMENT 85 1. Building '. 85 2. Apparatus for Handling Columns 85 3. Loading Apparatus 85 (a) Loading Ram 85' (b) Controlling Devices 87 (c) . Restraining Frame 87 (d) Bearing Details 88 (e) Capacity and Calibration 88 4. Testing Furnace ...' 88 (a) Combustion Chamber 89 (b) Burners 91 (c) Operating Details 91 5. Fire Stream Apparatus 91 VII. TEMPERATURE MEASUREMENTS 93 1. Instruments 93 (a) Indicating Potentiometer 93 (b) Recording Potentiometer 95 (c) Accessories 95 2. Furnace Temperatures 97 (a) Location of Furnace Thermocouples 97 (b) Thermocouple Mountings 97 (c) Connections to Instruments 98 3. Column Temperatures 98 (a) Attachment of Thermocouples to Column 98. (b) Location of Column Thermocouples 100 (c) Connections to Instruments 101 4. Method of Taking and Reducing Observations 101 5. Calibration of Thermocouples 102 (a) Furnace Thermocouples 102 (b) Column Thermocouples , 103 VIII. DEFORMATION MEASUREMENTS 105 1. General Outline 105 (a) Attachment and Protection of Wires 105 2. Unit. Compression and Expansion 107 . (a) Micrometers and Mounting 107 (b) Method of Taking and Reducing Observations 107 3. Center Deflection 107 4. Total Depression or Expansion 109 5. Calibration and Accuracy 109 8 FIRE TESTS OF BUILDING COLUMNS Page IX. METHOD OF TESTING 110 1. Loading Formulas and Applied Loads Ill (a) Working Loads Ill (b) Loading to Failure 2. Fire Exposure Ill (a) Character of Fire Ill (b) Preliminary Panel Tests Ill (c) Time-Temperature Curve 115 (d) Influence of Pyrometer Mounting on Indicated Tem- peratures 115 (1) Temperature Lag 115 (2) Radiation Effects 119 3. Fire and Water Test Procedure 120 4. Observations During Test 121 5. Observations After Failure 121 6. Photographic Records ' 121 X. RESULTS OF FIRE TESTS 122 1. Fire Test Results in Tables and Figures 122 2. Photographic Records 122 3. Furnace Temperatures 122 (a) Variations from Average Curves 122 4. Column Temperatures ' 130 (a) Temperature Variation over Length of Column 131 (b) Temperature Variation over Cross Section 131 (>c) Dehydration Points 131 5. Longitudinal Deformation and Average Temperature 131 (a) Computation of Average Effective Temperature 131 (b) Deformation Under Heat and Load 133 (c) Period of Expansion 135 ' (d) Maximum Column Temperatures 135 6. Total Vertical Deformation 139 (a) Before Failure 139 (b) At Failure 139 7. Lateral Deflection 139 (a) Before Failure 139 (b) Deflection at Failure '. 141 8.- Log of Fire Tests 142 (a) Unprotected Columns 142 Ob) Partly Protected Columns " 143 (c) Plaster on Metal Lath Protections ' 145 (d) Concrete Protections 146 >) Hollow Clay Tile Protections 151 Gypsum Block Protections. 158 (g) Brick Protections 160 (h) Reinforced Concrete Columns 161 (i) Timber Columns 162 XL RESULTS OF FIRE AND WATER TESTS 166 1. Applied Loads, Duration and Effect of Fire and Water 166 2. Photographic Records 166 3. Furnace and Column Temperatures 166 4. Longitudinal Deformation 166 5. Subsequent Loading Tests 166 6. Log'bf Fire and Water Tests 167 (a) Concrete Protections 167 Cb) Hollow Clay Tile Protections 169 (c) Gypsum Block Protections 171 (d) Plaster on Metal Lath Protection 172 (e) Reinforced Concrete Columns 172 (f) Unprotected Cast Iron Columns. .. 174 CONTENTS 9 Page XII. GENERAL SUMMARY AND DISCUSSION 176 1. Characteristics of Columns and Their Materials 176 (a) Structural Steel Columns 176 ( 1 ) Material and Fabrication 176 (2) Effect of Slenderness Ratio 176 (3) Lateral Deflection 177 ' (4) Vertical Deformation 177 (5) Load Carried by Covering 177 (6) Average Effective Temperatures 177 (7) General Cause of Failure 178 (b) Cast Iron Columns. 178 (1) Material and Manufacture 178 (2) Deformation and Temperature 179 (3) Cause and Character of Failure 179 (c) Pipe Columns 179 ( 1 ) Material and Manufacture 179 (2) Deformation and Temperature 180 (d) Reinforced Concrete Columns 180 (1) Mechanical Properties of the Concrete 180 (2) Deformation and Temperature 181 (3) Character of Failure 181 (e) Timber Columns 181 (1) Quality of Material 181 (2) Deformation and Temperature 181 (3) Cause of Failure 182 2. Useful Limits ' 182 (a) Structural Steel and Cast Iron Columns 182 (b) Pipe Columns 183 (c) Reinforced Concrete Columns 183 (d) Timber Columns 183 (e) Practical Application 184 3. Discussion of Test Data 185 (a) Difference in Columns, Test Exposure and Service Conditions 185 (1) Variations Due to Difference in Columns 185 (2) Variations Due to Difference in Load and Fire Conditions 187 (b) Unprotected Columns 188 (1) Structural Steel 188 (2) Cast Iron 189 (3) Pipe Columns 190 (c) Partly Protected Columns -. 190 (1) Effect of Section and Size 190 (2) Effect of Concrete Aggregate and Ties 191 (d) Plaster on Metal Lath Protections 191 (1) Material and Design 191 (2) Test Results 191 (3) Cracking Due to. Expansion of Covering '. 192 * * (4) Effect of Variation in Details of Application 192 (5) Effect of Water Application 192 10 FIRE TESTS OF BUILDING COLUMNS Page XII. GENERAL SUMMARY AND DISCUSSION. Continued. (e) Concrete Protections 193 (1) Mechanical Properties of the Concrete. 193 (2) Function of Concrete as a Covering Material 193 (3) Variations Due to Concrete Aggregate 194 (4) Comparison of 2-in. and 4-in. Protections 195 (5) Effect of Size ' 196 (6) Effect of Strength of Concrete 196 (7) Influence of Shape of Section and Covering 197 (8) Function of the Wire Tie 197 (9) Effect of Water Application 198 (f) Hollow Clay Tile Protections 198 (1) Mechanical Properties of the Tile 198 (2) Test Results 198 (3) Variations Due to Type of Clay and Details of Manufacture . (4) Comparison of 2-in. and 4-in. Protections 199 (5) Effect of Size 200 (6) Effect of Ties and Filling 200 (7) Effectiveness of Plastering 202 (8) Effect of Water Application 202 (g) Brick Protections 202 (1) Properties of the Brick 202 (2) Test Results 203 (h) Gypsum Block Protections 203 (1) Strength and Porosity of the Gypsum Block 203 (2) Comparison of 2-in. and 4-in. Protections 203 (3) Characteristic Fire Effects 205 (4) Heat Insulating Properties 205 (5) Effect of Water Application 205 (i) Reinforced Concrete Columns : 206 (1) Influence of Concrete Aggregate 206 (2) Effect of Form of Column and Reinforcement 206 (3) Recovery of Strength after Fire Test 207 (4) Effect of Water Application 207 ( j ) Timber Columns 208 ( 1 ) Unprotected Timber Columns 208 (2) Protected Timber Columns 208 (3) Strength After Fire Test 209 XIII. FIRE RESISTANCE PERIODS DERIVED FROM THE TEST RESULTS 210 1. Basis of Derivation 210 (a) Method of Computation 210 (b) Intervals 210 (c) Table of Fire Resistance Periods 210 (d) Derivation of Method 213 (e) Resistance to Water Application 214 (f) Size ^imitations 214 (g) Application to Building Conditions 215 2. Derivation of Fire Resistance Periods 217 (a) Unprotected Structural Steel Columns 217 (b) Partly Protected Structural Steel Columns 218 (1) Solid Section Columns 218 (2) Open Latticed Section 218 (c) Structural Steel Columns with Plaster on Metal Lath Protections ' 218 Single Layer Protection 219 Double Layer Protection 219 (1) (2) CONTENTS 11 (d) Concrete Protections on Structural Steel Columns 219 (1) Siliceous Gravel Concrete Protection 219 (2) Granite, Sandstone or Hard Coal Cinder Concrete Protection 220 (3) Trap Rock Concrete Protection 221 (4) Limestone or Calcareous Gravel Concrete Protection 221 (e) Hollow Clay Tile Protections on Structural Steel Columns 223 (1) Unfilled Protection 224 (2) Shale or Surface Clay Tile Protection with Con- crete Filling Reentrant Spaces 224 (3) Semi-fire Clay or Surface Clay Tile Protection with Full Concrete Filling 224 (4) Double 2-in. Tile Protection 224 (f ) Brick Protections 225 (g) Gypsum Block Protections , 225 (h) Cast Iron Columns 225 ( 1 ) Unprotected Columns 225 (2) Plaster on Metal Lath Protection 226 (3) Concrete Protection 226 (4) Hollow Clay Tile Protection 226 (i) Unprotected Pipe Columns 226 ( j ) Reinforced Concrete Columns 227 (k) Timiber Columns 228 (1) Unprotected Timber Columns 228 (2) Protected Timber Columns 228 3. Conditions Governing Fire Duration in Buildings 228 APPENDIX A s . .230-262 Views of Columns Before and After Test Fig. Nos. 58 to 89 APPENDIX B. '. 263-320 Time-Temperature Curves Fig. Nos. 90 to 145 APPENDIX C 321-347 Deformation and Average Temperature Curves Fig. Nos. 146 to 171 APPENDIX D 349-379 Ta'bles of Auxiliary Tests of Materials Table Nos. 5 to 40 APPENDIX E 380-388 Previous Investigations APPENDIX F 389 Centigrade and Fahrenheit Conversion Table 12 FIRE TESTS OF BUILDING COLUMNS TABLES Page 1. Nominal and Measured Areas of 'Structural Steel Sections 25 2. Properties of Timber in Test Columns 34 3a. Unprotected Structural Steel Columns. Fire Tests 37 jb. Unprotected Cast Iron and Pipe Columns. Fire Tests . . 38 3c. Columns Partly Protected by Concrete. Fire Tests 39 3d. Columns Protected by Plaster on Metal Lath. Fire Tests 40 3e. Columns Protected by Concrete. Fire Tests 43-45 3f. Columns Protected by Hollow Clay Tile. Fire Tests 47-49 3g. Columns Protected by Gypsum Block. Fire Tests 51 3h. Columns Protected by Brick. Fire Tests 52 3i. Reinforced Concrete Columns. Fire Tests 53 3j. Timber Columns. Fire Tests 54 4a. Columns Protected by Concrete. Fire and Water Tests 56 4b. Columns Protected by Hollow Clay Tile. Fire and Water Tests... 57 4c. Columns Protected by Gypsum Block. Fire and Water Tests 57 4d. Column Protected by Plaster on Metal Lath. Fire and Water Tests 58 4e. Reinforced Concrete Columns. Fire and Water Tests 58 4f. Unprotected Cast Iron Columns. Fire and W r ater Tests 59 5 to 40. Auxiliary Tests of Materials. Appendix D 350-379 41. Computed and Applied Working Loads 110 42a. Results of Fire Tests. Unprotected Columns 123 42b. Results of 'Fire Tests. Columns Partly Protected by Concrete 124 42c. Results of Fire Tests. Columns Protected by Plaster on Metal Lath 124 42d. Results of Fire Tests. Columns Protected by Concrete 125 42e. Results of Fire Tests. Columns Protected 'by Hollow Clay Tile... 126 42f. Results of Fire Tests. Columns Protected by Gypsum Block..... 127 42g. Results of Fire Tests.. Columns Protected by Brick 127 42h. Results of Fire Tests. Reinforced Concrete Columns 128 42i. Results of Fire Tests. Timber Columns 128 43. Time to Failure, Period of Expansion and Maximum Column Tem- peratures 136-137 44. Results of Fire and Water Tests. Opposite page 166 45. Compressive Strength of Timber, after Fire Test 209 46. Fire Resistance Periods Derived from the Test Results 211-213 FIGURES 1. Details of Structural Steel Columns. Rolled H and Plate and Angle Sections 20 2. Details of Structural Steel Columns. Plate and Channel and Latticed Channel Sections 21 3. Details of Structural Steel Columns. Z-bar and Plate and I-beam and Channel Sections 22 4. Details of Structural Steel Columns. Latticed Angle and Starred Angle Sections 23 5. Calipers for Measuring Steel Shapes 24 6. Details of Cast Iron Columns 27 7. Details of Pipe Columns 28 8. Details of Vertically Reinforced Concrete Columns 30 9. Details of Hooped Concrete Columns and Column Head Protection.. 31 10. Details of Timber Columns.... 33 CONTENTS 13 FIGURES. Continued. Page 11. Forms and Staging for Placing Concrete 60 12. Concrete Mixer 62 13. Placing of Clay Tile and Gypsum Block Protections 64 14. Concrete Cylinder after Test 73 15. Average and Range of Compressive Strength of 1:2:4 and 1:2:5 Concrete 75 16. Average and Range of Compressive Strength of 1:3:5 Concrete 76 17. Effect of Consistency on Compressive Strength of Concrete, Av. Age, 28 days 77 18. Effect of Consistency on Compressive Strength of Concrete. Av. Age, 490 days 77 19. Effect of Time of Mixing on Compressive Strength of Concrete 78 20. Modulus of Elasticity of Concrete at 450 to 850 Ib. per sq. in 79 21. Modulus of Elasticity of 1:2:4 Concrete at 650 Ib. per sq. in. Vari- ation with Ultimate Compressive Strength 79 22. Effect of Consistency on Modulus of Elasticity of Concrete at 650 Ib. per sq. in 80 23. Average and Range of Compressive Strength of Mortar and Plaster 81 24. Plan of Testing Room 84 25. Elevation of Testing Machine 86 26. General View of Testing Machine 89 27. Control Board 90 28. Fire Stream Apparatus 90 29. Temperature Measuring Instruments 30. Wiring Diagram of Indicating Potentiometer 93 31. Location of Furnace and Column Thermocouples 94 32. Detail of Furnace Thermocouple Mounting 96 33. Diagram Showing Method Used for Measuring Deformation.. 105 34. Testing Furnace with Furnace Couples, Column and Deformeter in Place 104 35. Detail of Insulating Tube and Insert 106 36. Apparatus for Measuring Deformation 108 37. Furnace Temperatures, Preliminary Panel Tests 113 38. Preliminary Tile Panels after Test 112 39. Comparison of Furnace Temperatures used in Fire Tests 114 40. Lag Correction for Furnace Pyrometers 116 41. Effect of Radiation on Indication of Furnace Pyrometers '.) 118 42. Time to Failure of Columns in Fire Tests Series 129 43. Temperature Variation Over Cross Section of Typical Column's.. 130 44. Assumed Temperature Variation Between Thermocouple Points. 132 45. Expansion Period of Steel, Cast Iron and Concrete Columns in Fire Test Series 134 46. Total Expansion, Test Nos. 10A, 76, 77, 110, 114 and 115 138 47. Depression of Top of Timber Columns 140 48. Results of Fire Tests Compared by Groups 186 49. Effect of Load on Fire Resistance, Unprotected Structural Steel Columns 189 50. Effect of Size^ Partly Protected Columns 190 51. Comparison of 2-in. and 4-in. Concrete Protections 195 52. Effect of Size, Concrete Protections 196 53. Comparison of 2-in. and 4-in. Hollow Clay Tile Protections 199 54. Effect of Size, Clay Tile and Brick Protections 200 55. Effect of Ties and Filling, Hollow Clay Tile Protections 201 56. Comparison of 2-in. and 4-in. Gypsum Block Protections 205 57. Blocks from Gypsum Coverings after Test 204 58 to 89. Views of Columns Before and After Test. Appendix A... 231-262 90 to 145. Time-Temperature Curves. Appendix B 265-320 146 to 171. Deformation and Average Temperature Curves. Appendix C 322-347 I. INTRODUCTION 1. PURPOSE The purpose of this investigation is to ascertain (1) the ulti- mate resistance against fire of protected and unprotected columns as used in the interior of buildings ; (2) their resistance against impact and sudden cooling from hose streams when in a highly heated condition. While columns form the most important element in the strength of a building, few representative tests have been made to determine their ability to support load when exposed to fire, and fire experience has only a limited value, due to the many unknown variables involved. As a consequence, wide differences in require- ments relating to the protection of columns against fire exist be- tween different municipal codes and other published regulations. This investigation was undertaken to obtain information on which proper requirements for the more general types of columns and pro- tective coverings can be based. 2. SCOPE OF TESTS The present series consists of 106 tests of columns, of which 91 were fire tests and 15 fire and water tests. The fire test series includes (1) tests of representative types of unprotected structural steel, cast iron, concrete-filled pipe, and timber columns ; (2) tests wherein the metal was partly protected by filling the reentrant portions or interior of columns with con- crete; (3) tests wherein the load carrying elements of the columns were protected by a 2-in. or 4-in. thickness of concrete, hollow clay tile, clay brick, gypsum block, and also, single or double layer of metal lath and plaster; (4) reinforced concrete columns with 2-in. integral concrete protection. The covering materials for each class of protection were ob- tained from the main producing regions of the c'ountry, the object being to include samples from the principal mineralogical subdi- visions that find general application in building construction. A large number of auxiliary tests of constituent materials were made, including several hundred compression tests on the concrete em- ployed. The test columns were designed for a working load of approxi- mately 100,000 lb., as calculated according to accepted formulas, 15 16 , INTRODUCTION the amount varying somewhat for the different sections. The load was maintained constant on the column during the test, the effi- ciency of the column or its covering being determined by the length of time it withstood the combined load and fire exposure. The latter was produced by placing the column in the chamber of a gas-fired furnace whose temperature rise was regulated to conform with a predetermined time-temperature relation. Meas- urements were taken of the temperature of the furnace and test column and of the deformation of the latter due to the load and heat. In the fire and water tests the column was loaded and exposed to fire for a predetermined period, at the end of which the furnace doors were opened and a hose stream applied to the heated column, the duration of the application and pressure at the nozzle varying with the length of time the corresponding type of column with- stood the regular fire tests. 3. ACKNOWLEDGMENTS The tests were jointly conducted by the Associated Factory Mutual Fire Insurance Companies, the National Board of Fire Un- derwriters, and the Bureau of Standards. The fire tests were made at Underwriters' Laboratories, Chicago, 111. The furnace and relat- ed equipment were designed and constructed by Underwriters' Lab- oratories during the period 1912 to 1917, the work being coordinated with a general building program that was carried out by them at that time. Its use, except for repairs and replacements, was donated for the tests. Preliminary work relative to the testing schedule was begun as early as 1910 by the Associated Factory Mutual Fire In- surance Companies and Underwriters' Laboratories, the cooperation of the Bureau of Standards being obtained in 1914. A final schedule of tests was adopted in March, 1916. The preparatory work of cov- ering and placing the test columns extended from May, 1916, to May, 1917. With the completion of the equipment, testing of col- umns began in June, 1917, and was completed in December, 1918. This report in its final form was approved by the cooperating parties in December, 1920. Publication of the test results is made by the Bureau of Standards 'in Paper No. 184 of its Technologic series. The apparatus for measuring temperature and deformation was supplied by the Bureau of Standards. Auxiliary physical and chemical tests of the materials of the test columns and their protective coverings were made at the Washington and Pittsburgh Laboratories of the Bureau. ACKNOWLEDGEMENTS 17 The expense for material and labor was shared on an equal basis by the three cooperating units. The materials were in part purchased under the usual specifications, and in part sup- plied gratis by the following companies, whose cordial cooperation is herewith acknowledged: American Bridge Co., Chicago, 111., steel test columns. Bethlehem Steel Co., South Bethlehem, Pa., steel test columns. Chicago Bridge & Iron Works, Chicago, 111., steel test columns. R. D. Cole Manufacturing Co., Newnan, Ga., steel test columns. Pittsburgh-Des Moines Steel Co., Pittsburgh, Pa., steel test columns. U. S. Cast Iron Pipe & Foundry Co., Burlington, N. J., cast iron test columns. Lally Column Co., Cambridge, Mass., steel pipe test columns. National Lumber Mfrs. Assn., Chicago, 111., timber test columns. Southern Pine Assn., New Orleans, La., tiniber test columns. West Coast Lumbermen's Assn., Seattle, Wash., timber test col- umns. Corrugated Bar Co., Buffalo, N. Y., reinforcing steel. Associated Metal Lath Mfrs., 'Chicago, 111., expanded metal lath. Zander-Reum Co., Chicago, 111., woven wire lath. Chicago Portland Cement Co., Chicago, 111., Portland cement. Marblehead Lime Co., Chicago, 111., lime. Pelee Island Sand & Gravel Co., Cleveland, Ohio, sand. Phoenix Sand & Gravel Co., New York, N. Y., sand. American Sand & Gravel Co., Chicago, 111., sand and gravel. Chicago Gravel Co., Chicago, 111., sand and gravel. Union Sand & Material Co., St. Louis, Mo., ,sand and gravel. Haverstraw Crushed Stone Co., New York, N. Y., crushed stone. Ohio Quarries Co., Cleveland, Ohio, crushed stone. Rockport Granite Co., Rockport, Mass., crushed stone. White Fireproof Construction Co., New York, N. Y., hard coal cinders. Camp Conduit Co., Cleveland, Ohio, hollow clay tile. National Fireproofing Co., Pittsburgh, Pa., hollow clay tile. Whitacre Fireproofing Co., Waynesburg, Ohio, hollow clay tile. Gypsum Fireproofing Co., Chicago, 111., gypsum block. Keystone Fireproofing Co., New York, N. Y., gypsum block. Bestwall Manufacturing Co., Chicago, 111., gypsum wall board. The participation of the Associated Factory Mutual Fire In- surance Companies was under the direction of H. O. Lacount, As- sistant Secretary and Engineer, and they were represented on the preliminary conference and preparatory work by C. W. Mowry, and at different times in conducting the tests and preparing the results for publication, by R. E. Manning, W. G. Lawrence and R. E. Wilson. The National Board of Fire Underwriters participated through Underwriters' Laboratories, the work being under the direction of W. C. Robinson, Vice President, assisted by F. W. Frederick, W. G. Howell and F. Taylor in designing and constructing the testing furnace and related equipment, and at different times by G. W. Riddle and R. K. Porter in conducting the tests. J8 INTRODUCTION The cooperation of the Bureau of Standards was under the administrative direction of C. W. Waidner, Chief of the Division of Heat and Thermometry, their representatives being S. H. Ingberg and H. K. Griffin, who were actively associated with the work for the periods 1914 to 1920 and 1917 to 1920, respectively, the former being in direct charge of the experimental program. Technical assistance for extended periods was given by A. J. Steiner and R. F. Zeunnert. Mineralogical analyses of concrete aggregates were made by R. S. Knappen of the Department of Geology of the University of Chicago. Acknowledgment is also due to a number of engineers, con- tractors, architects and public officers who kindly examined a pre- liminary draft of the schedule of tests which was submitted to them. Their criticisms and suggestions were duly considered in formulating the final program. II. DESCRIPTION OF COLUMNS 1. STRUCTURAL STEEL COLUMNS (a) Details of Design In Figs. 1 to 4 are shown details of all structural sections em- ployed in the tests. The lower 12 ft. 8 in. constitute the test col- umn proper, the upper enlarged extension 3 ft. in length serving merely as a means for transmitting the load to the column. This head is protected by concrete as shown in Fig. 9 (p. 31), and being above the ceiling line is not directly exposed to the heat of the test- ing chamber. The bottom base angles are designed to develop about one- half of the transverse strength of the column considered as a beam at ordinary temperature, and during the test are embedded in the fireproofing of the base plates of the testing machine. The top anchorage is designed to develop the full transverse strength of the column. The test columns are provided with brackets near the top to introduce conditions affecting the application of the protective cov- erings similar to those obtaining in building construction. On account of the prevailing use of the solid rolled and built- up H sections, more than one-half of the total number of steel columns used in the tests were of these types. (b) Bearings The column bases were specified to be finished by milling. While this had been done in almost all cases, it was necessary to improve most of the bearings by grinding, in order not to induce too uneven stress distribution in the columns when loaded. (c) Riveting This was examined by striking the rivet heads with a ham- mer. Very few loose rivets were found and these were redriven before testing. (d) Initial Straightness Before being covered or tested, the columns were examined for Straightness by measuring from points on the column as placed in vertical position to a fine wire stretched from base angles to bracket. The columns were generally straight within % in. and in all cases within -^ in. 19 20 DESCRIPTION OF COLUMNS PLATE & ANCLE Fig. 1. Details of structural steel columns. Rolled H and Plate and Angle sections. STRUCTURAL STEEL COLUMNS 21 Fig. 2. Details of structural steel columns. Plate and Channel and Latticed Channel sections. 22 DESCRIPTION OF COLUMNS I-BEAM &, CHANNEL Fig. 3. Details of structural steel columns. Z-bar and Plate and I-beam and Channel Sections. STRUCTURAL STEEL COLUMNS 23 LATTICED ANGLE &TAHRED ANGLE Fig. 4. Details of structural steel columns. Latticed Angle and Starrea Angle sections. 24 DESCRIPTION OF COLUMNS (e) Properties of Sections The area of one or more sections of each type was obtained by calipering. The special gauges used are shown in Fig. 5. The large gauge having a range from to 12 in. was used for outside measurements, the distance between the point of the pin and the point of the dial stem at zero reading being obtained by means of calibrated end measuring rods. The inside caliper has a range from 3 1 /. to 6 l / 2 in., the length between its points at zero reading being determined by measurement in the outside gage. Shape and area of fillets and corners were obtained from plaster impres- sions. Fig. 5. Calipers for measuring steel shapes. STRUCTURAL STEEL COLUMNS 25 A comparison of nominal or hand book areas and measured areas is given in Table 1, the two being generally in agreement within one percent and in all cases within 4 percent. In calculat- ing the loads to be carried during the fire test, the nominal area was used for all columns, the main dimensions of the section mem- bers being measured to ascertain their nominal size. The latter was found to be as called for on the details except in the .case of two plate and angle 'and two plate and channel columns where the plates were ^ in. heavier than required. Values of other essential properties of the sections are given in Table 3a (p. 37). TABLE 1. NOMINAL AND MEASURED AREAS OF STRUCTURAL STEEL SECTIONS Test No. SECTION SECTION MEMBERS Nominal Area, Sq. In. Measured Area, Sq.In. 15 30 50 Rolled H Rolled H...- Plate and Angle... Solid Rolled H 34.5 Ib Solid Rolled H 34 5 Ib 3.00 10.00 10.17 10.17 * 13.00 2.09 9.97 10.00 10.05 12.90 1 Plate J^ by 6 in 4 Angles 3 by V/z by ^ in 51 110 30 107 54 Plate and Angle... Plate and Angle. . . Plate and Channel Plate and Channel. Latticed Channel.. 1 Plate^ by Gin. . . 4 Angles 3 by 2^ by ^ in 1 Plated by Gin... 4 Angles 3 by % by Y 2 in .' 2 Plates & by Sin... 3.00 10.00 13.00 13.00 9.26 8.76 7.78 2.92 9.94 2.99 10.21 4.51 4.73 4.19 4.57 12.80 13.20 9.24 8.70 7.80 3.00 10.00 4.50 4.76 4.00 4.76 2 Channels 6 in. 8 Ib 2 Plates M by Sin... 2 Channels 6 in 8 Ib 2 Channels 9 in. 13^ Ib 41 56 Z-bar and Plate... Z-bar and Plate. . . 1 Plate M by 5% in 4 Z-bars 3 by J^ in 1.44 7.88 1.44 7.88 9.32 9.32 1.40 7.85 1.48 7.59 9.31 9.07 1 Plate^ by 5% in... 4 Z-bars 3 by M in , 44 58 I-beam and Channel I-beam and Channel 1 I-beam 7 in. 15 Ib 2 Channels 7 in. 9% Ib 1 I-beam 7 in. 15 Ib 4.42 5.70 4.42 5.70 10.12 10.12 4.54 5.71 4.59 5.76 10.25 10.35 2 Channels 7 in.-9M Ib 46 Latticed Angle.... 4 Angles 3 by 3 by 5^ in 8.44 8.40 26 DESCRIPTION OF COLUMNS 2. CAST IRON COLUMNS (a) Details of Design and Manufacture Structural details are given in Fig. 6. The columns shown in (a) and (b) were made by a Chicago foundry experienced in the making of building castings. They were cast horizontally with continuous core supported by chaplets, and single gate and riser, the gate being at one end and the riser at the other. Five of these columns were tested with ends restrained by bolting to base plates at top and bottom as shown in (a), and two were tested with ends not restrained as shown in (b). In the latter case the bolts at the bottom were omitted and at the top the column was cut at the junction with the head, a bearing plate being in- serted between the cut surfaces. A U-bolt and strap on each side served to hold the column end in case the column broke at failure. Three columns were of the cast iron pipe type with detached cap as shown in (c) and (d) of Fig. 6. These columns were cast in vertical position. In testing substantially the same bearing de- tails were used as for the horizontally cast columns that were tested with ends not restrained. (b) Bearings The ends of the columns were milled, the bearings being in all cases fairly even and true. All bearing surfaces of caps and bear- ing plates were machined. The top and bottom bearings were protected by fireproofing the same as for the structural steel col- umns, the length exposed to the fire being 12 ft. (c) Initial Straightness The amount and direction of initial curvature was determined in the same manner as for the structural- steel columns. The col- umns that were cast horizontally were straight within y% in. and those cast on end were straight within -fy in. (d) Variation in Metal Thickness In the case of the horizontally cast columns, the core at the midpoint of the length was found to have been displaced by amounts varying from -^ to 54 m - for the individual columns. The minimum thickness of metal was % in. against a nominal thick- ness of 24 m - Thie area of metal exceeded the nominal area by amounts up to about 1 sq. in. The exact effective area was diffi- cult to determine on account of the roughness of the interior sur- face. For the vertically cast columns the thickness varied from ^ in. to 24 i n - against a nominal thickness of H in., the area being gen- erally about y* sq. in. in excess of the nominal. CAST IRON COLUMNS 27 a. Li C-t \STON SIDE (b) CA 57 ;o \ot VZ7A/I .(d ^^4 = & (O) DETAIL OF CAP ENDS NOT RESTRAINED ROUND CAST IRON Fig. 6. Details of cast iron columns. 28 DESCRIPTION OF COLUMNS \ fl c j I 1 ' I . // k ^ 1 1 [_ 1 n PL A/A/ REINFORCED PIPE COLUMNS Fig. 7. Details of pipe columns. PIPE COLUMNS 29 3. PIPE COLUMNS (a) Details of Design and Manufacture Two concrete-filled pipe columns were tested, one made with i standard 7-in. steel pipe, and the other with a standard 8-in. >ipe reinforced in the fill with four 3*^ by 3J4 by ^ in. angles -iveted back to back. Details of columns and bearings are given n Fig. 7. The details at the top are similar to those of the cast iron columns that were tested with unrestrained ends except that i short strut was placed between the top of the cap and the upper Dearing plate to obtain conditions more nearly representative of use in buildings. The 7-in. pipe column was filled at the manufacturer's plant especially for the test and specimens of concrete and concrete ag- gregates were secured. The concrete mixture was 1 part Port- land cement, iy 2 parts Cambridge, Mass., bank sand, and 3 parts crushed blue trap rock quarried at Westfield, Mass. The reinforced pipe column was obtained from a stock of completed :olumns, and specimens of the concrete aggregates could. not be obtained, but they were said to be the same as (or the 7-in. column. (b) Bearings The bearings were square and unrestrained. The bearing sur- faces of the caps were unfinished, base and top bearing plates were machined. The pipes had sawed ends that were fairly even. The concrete on the bottom bearing of the 7-in. pipe column projected about -fa in. below the pipe. 4. REINFORCED CONCRETE COLUMNS (a) Details of Design The types tested include square and round longitudinally rein- forced columns, and round columns with lateral reinforcement of spiral hooping and longitudinal bar reinforcement. Details are. shown in Figs. 8 and 9. The spiral reinforcement constitutes in volume about one percent of the contained concrete. The size and spacing of the lateral ties in the longitudinally reinforced columns represent current practice with respect to this detail. The concrete was of 1 :2 :4 mixture. In the columns for the fire tests, Fox River (111.) sand with Chicago limestone and Long Island (N. Y.) sand with New York trap rock were the two com- binations of aggregates used. For the fire and water tests each column was cast in three 4-ft. sections with concrete of different aggregates in each section. DESCRIPTION OF COLUMNS SECTION B'-B ROUND VERTICALLY REINFORCED CONCRETE COLUMNS Fig. 8. Details of vertically reinforced concrete columns. REINFORCED CONCRETE COLUMNS 31 Mt SECTION C-C SECTION A-/\ DETAIL, OF HEAD PROTECTION FOR STEEL, &> COLUMNS SECTION B -B HOOPED CONCRETE COLUMN Fig. 9. Details of heaped concrete column and column head protection. 32 DESCRIPTION OF COLUMNS (b) Bearings and End Restraint The lower ends of the vertical bars were ground true and abutted on the base plate on which the column was cast, the upper ends of the bars terminating y 2 in. below the top bearing plate. The head was cast monolithic with the test column proper, and was suitably reinforced and anchored into the top bearing plate. The latter was set in Portland cement mortar. At the bottom the col- umn was tied to the base plate with four %-in. bolts. 5. TIMBER COLUMNS (a) Species of Timber Tests of timber columns include four with long leaf yellow pine and two with Douglas fir, these two species being chosen on account of wide use in heavy timber construction. Details of col- umns and bearings are given in Fig. 10. The yellow pine columns were cut from timber grown in Pike County, Miss. The Douglas fir columns came from the northern Douglas fir region of the Pacific Coast. (b) Cap and Bearing Details In the construction shown at (a) in Fig. 10, the load is trans- mitted to the column through a cast iron pintle and cap. Timbers and flooring cover the top surface of the cap and completely enclose the pintle in a manner similar to that used in standard applications of mill construction. In the construction shown at (b) the load is transmitted through a timber strut and steel plate cap, this method of column and beam support typifying another form of standard practice with regard to these details. The timber and bearings were finished so as to be fairly even and perpendicular to the axis of the column. (c) Properties of the Timber The chief characteristics of the timber are given in Table 2 (p. 34). The columns were select structural material with few knots or other defects. They were surfaced on the sides, and the corners were slightly beveled. A nominal section of 11^ by 11^ in. was assumed in calculating the working load. The number of annual rings per inch and the percentage of summerwood were determined on a representative line over the third, fourth and fifth inches from the pith, the values given being the average for the two end faces. The rosin content was obtained by extracting borings from representative points in the section with benzol and drying to constant weight at 70 C. TIMBER COLUMNS 33 4_ X l-_^-4~-_T__- J> DETAlL OF C AP Ilk 2'STEEL PIN - (a) CAST CAP AND PINTLE (b) STEEL PLATE CAP TIMBER COLUMNS Fig. 10. Details of timber columns. 34 DESCRIPTION OF COLUMNS The moisture content and dry weight were determined from discs 1 in. thick cut 2 ft. and 4 ft. from the end of a timber of the same size as the test columns and which had been subjected to the same storage conditions. These were dried to constant weight at 100 C., the percentage moisture, which includes besides water other substances volatile at the given temperature, being based on the dry weight. In point of general quality of material the test columns con- formed with the requirements of published specifications for struc- tural timber. The size of the finished section was smaller by about Y% in. than as specified by some regulations. TABLE 2. PROPERTIES OF TIMBER IN TEST COLUMNS Test No. Species Dimension of Section. In. Number of Rings per In. Summer- wood, Percent * Rosin Content, Percent 'Moisture Content, Percent Weight per Cu. Ft.. Pounds **As Tested *Oven Dry 78 Longleaf pine H&byll^ 14 35 N 41.3 \ 79 Longleaf pine 11M by 11M 17 50 SO Longleaf pine lltfbyllft 11 35 7.07 17.1 41.3 34.7 81 Longleal Pine 11% by 11% 14 35 ) 46.7 , 82 Douglas fir 11% by 11% 9 33 \ ) 36.1 ^1 83 Douglas > 1.34 > 26.2 > 30.1 fir 11% by 11% 10 33 J j 39.0 J 'Determined from representative samples. "Determined by weighing the test columns. III. SCHEDULE OF TESTS 1. GENERAL CONSIDERATIONS (a) Object and Limitations The present investigation, in point of method of testing and types of protection tested, applies particularly to the interior col- umns of a structure. Due to greater exposure and smaller amount of protection these form in general a more critical element in the column strength of a building as affected by fire, than do the wall columns. The size of the test columns in the present series is representa- tive of those present in buildings of moderate height and of those under upper floors in higher buildings. The sizes involved were deemed to be best adapted for the initial investigation of the many variables pertaining to the fire resistance of building columns as designed and protected according to methods of modern building practice. Subsequent investigation of columns designed for the heavier loads should be materially simplified by results of tests with columns of the proportions chosen for the present series. The number of variables presented by the variety in material and form of columns, material and amount of protection as well as the different methods of application, is greater than can be fully covered by a single series of tests, considering the limitations in time and expense incident with such an effort. It was necessary, therefore, to limit the investigation to the main forms of construc- tion and protection, and in amount of protection, to the minimum and maximum as generally used. (b) Preliminary Work on Schedule This consisted of (1) investigation of existing methods of column design and column protection including comparative study of the requirements of municipal buiraing codes ; (2) inquiry into field methods of erection and placing of columns and coverings ; (3) study of the geographical distribution of production and use of materials for protective coverings of each type as an aid in selecting representative materials for the tests; (4) preparation of a pre- liminary schedule of tests which was submitted to engineers, con- tractors, architects and public officers for criticisms and suggestions ; (5) consideration of criticisms offered and formulation of final test- ing program. 35 36 SCHEDULE OF TESTS In amount of protection for interior columns, building ordin- ances require in general from 2 to 4-in. thicknesses of material out- side of load carrying elements, the requirements for the same grade of construction varying between these limits, as prescribed by different city codes. As it was considered desirable to determine the fire resisting value of constructions in general use, it was de- cided to test protections of 2 and 4-in. commercial thicknesses, which, in connection with tests of unprotected and partly protected columns, as also of plaster on metal lath protections, were deemed to include the general range of protection occurring in current building construction. The schedule, as finally adopted at the conference of repre- sentatives of the cooperating units held in March, 1916, embodied many suggestions received in criticism of the preliminary schedule and was considered by all concerned to be the best procedure prac- ticable, considering the extent of the field and the number of tests to be made. 2. SCHEDULE OF FIRE TESTS (a) Unprotected Columns Details of design of structural steel, cast iron and pipe columns are shown in Figs. 1, 2, 3, 4, 6 and 7, and the calculated and applied working loads pertaining to each section are given in Table 41 (p. 110). The unprotected structural steel columns, which comprise one of each section type, are scheduled in Table 3a together with the chief properties of their sections. These hold for the lower 12 ft. 8 in. of their length. The list of unprotected fast iron and pipe columns is given in Table 3b. Of the unprotected cast iron columns, one was tested with ends restrained and three with unrestrained ends. Of the latter, one column, No. 11, was filled with concrete to increase its fire re- sistance. They were all horizontally cast except No. 10A. The tests with pipe columns comprise one with a standard 7-in. pipe having plain concrete fill, and one with an 8-in. pipe rein- forced in the fill with structural angles. SCHEDULE OF FIRE TESTS 37 TABLE 3a. SCHEDULE OF FIRE TESTS Unprotected Structural Steel Columns 1= Effective Length, 12 ft. 8 in. Test No. SECTION SECTION MEMBERS Nomi- nal Area, Sq. In. ^east Radius of Gyra- tion, r, In. r 1 ~"1 Rolled H 9 Solid Rolled H, 8 in. 34J4 lb.. 10.17 2.01 75.6 u-e-^J 2 Plate and Angle ^^fc 1 Plate J^ by 6 in 4 Angles, 3 by 2^ by H in 13.00 1.36 111.8 3 Plate and Channel <& 2 Plates, Ji by 8 in 2 Channels 6 in 8 lb 8.76 2.35 64.7 & S"H ~ Latticed Channel & 2 Channels, 9 in. 13M lb Single lattice, ^ by 2 in 7.78 3.43 44.0 & f^ t-r J pM* 64' 1 Plate l /i by 5% in 5 Z-bar and Plate 4 Z-bars, 3 by M in 9.32 1.86 81.7 c- /tf-=r 6 I-beam and 4 jf 7 Channel C-njf^r 1 I-beam, 7 in. 15 lb 2 Channels, 7 in. 9% lb 10.12 2.11 72.1 7 Latticed Angle 1 9* 4 Angles, 3 by 3 by H in Single lattice, M by 2^ in 8.44 3.73 40.7 jJT~l 4 Angles, 3 by 3 by % in 1 Plate % by 6% in 13.27 1.40 108.5 2 Plates, ^ by 3H in 38 SCHEDULE OF TESTS TABLE 3b. SCHEDULE OF FIRE TESTS Unprotected Cast Iron and Pipe Columns Test No. SECTION DETAILS Nom- inal Area Sq. In. Effec- tive Length, 1, In. Leasl Radi- us of Gyra- tion, r.In. 1 r 9 Round Cast Iron, | j Si' Ends restrained 14.73 152 2.23 68.2 Horizontally cast ^^^^ 10 Round Cast Iron, 1 5i" Ends not restrained 14.73 152 2 23 68.2 Horizontally cast ^^^ L. 10-A Round Cast Iron, f |g- Vertically cast ^^ ^\\ Ends not restrained 14.45 ^ 2.38 63.2 11 Round Cast Iron, X^V I Horizontally cast, &~ A . ' *.' 5i" Concrete filled |^o"_J^ 1 , Ends not restrained Concrete, 1:2:4 Portland cement Joliet sand 14.73 152 2.23 68.2 L-5h 4 Joliet gravel 12 Steel Pipe, /? ' ?\ L Concrete filled L>' o 4 j Ends not restrained Concrete, 1:1}^ :3 Portland cement Steel 6.93 Con- 149 2.34 63.9 t^<* Cambridge sand Westfield blue trap crete 38.7 if . 13 Reinforced (fj^ft 1 ^) S* Steel Pipe, ^ / 1 Concrete v^ B ^ [ 3- Ends not restrained 4 angles inside pipe, 3^ in. 3^ in. Y* in. Concrete same as for No. 12 Steel 18.36 Con- crete 152^ 2.24 68.2 filled {, QS J ' ' 40.1 4 3x$ f (a SCHEDULE OF FIRE TESTS 39 TABLE 3c. SCHEDULE OF FIRE TESTS Columns Partly Protected by Concrete Test No. 14 15 16 17 18 19 20 21 22 SECTION PROTECTION Mixture Material 1:2:4 1:2:4 1:2:4 1:2:4 1:3:5 1:3:5 1:3:5 1:2:4 Portland cement Joliet sand Joliet gravel Portland cement Plum Island sand Rockport granite Portland cement Long Island sand New York trap Portland cement Long Island sand Hard coal cinders Portland cement Long Island sand New York trap Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Portland cement Long Island sand New York trap Portland cement Fox River sand Chicago limestone Rolled H * ' f ^ f "%? B " Rolled H L Q- J Plate and Angle i^lV^-a-f T Plate and Angle 1, /-a* J 1 Latticed Channel i^ ^T^ft L1||1-I^J NaSWire Z-bar and Plate $ vpWWy t f iii" 8 No 5 Wire I " K Latticed Angle I 1 vd.*'. 'dj II L //i : NOTE: The horizontal ties, corsisting of %-in. bars or No. 5 (B. & S. gauge) wire, are bent around or wired to the vertical %-in. bars, and are spaced 18 in. apart vertically. 40 SCHEDULE OF TESTS TABLE 3d. SCHEDULE OF FIRE TESTS Columns Protected by Plaster on Metal Lath Test No. SECTION *PROTECTION 23 24 25 26 27 r9? n Two 2-coat layers of Portland cement plaster on No. 24 expanded metal lath, each layer 1 in. thick, with a %-in. air space between layers Two 2-coat layers of Portland cement plaster on woven wire lath, %-in. mesh, each layer J-8 in. thick, with a %-in. air space between layers One 2-coat layer of Portland cement plaster, 1 in. thick, on No. 24 expanded metal lath One 2-coat layer of Portland cement plaster, l^s in. thick, on No. 24 expanded metal lath One 2-coat layer of Portland cement plaster, 1V in. thick, on high ribbed expanded metal lath with ?/3-in. broken air space Plate and Angle j ) 1X1 ! -' -'- ' ' >| J 7j^3n Plate and Channel 9*' ;-spp 1 * /34" 1 Z-bar and Plate '' Hi j I /37 \ Latticed Angle ; j. & Round Cast Iron \Uf \*\ Column Section same as No. 9 fc\\^ Jim *The plaster consisted of 1 part Portland cement, 1/10 part hydrated lime, 2Y 2 parts coarse lake tend. Hair was used in the first coat; the second coat was trowelled smooth. SCHEDULE OF FIRE TESTS 41 (b) Partly Protected Columns These include nine structural steel columns partly protected by -filling the reentrant portions or interior with concrete and are scheduled in Table 3c, where also are shown the detail sections. The proportions of the concrete mixtures used throughout this investigation are based on volume parts of the respective materials, Portland cement, sand and coarse aggregate, taken in the given order. One bag of Portland cement weighing 96 Ib. net was taken to be one cu. ft. The sand and coarse aggregate were meas- ured by volume in the condition of density incident with shovel- ing them into the measures. The concrete sands as used had an average moisture content of 3 percent. The Portland cement used in all tests of the whole series, except in those with pipe columns, was supplied from a mill in the Chicago district. (c) Columns Protected by Plaster on Metal Lath Details of protection are given in Table 3d. The metal lath in Nos. 23, 25 and 26 was No. 24 expanded metal weighing 3.4 Ib. per sq. yd. including paint. That for Test No. 24 was of a 0.046 in. diameter wire, woven into %-in. square mesh and weighing painted 3.2 Ib. per sq. yd. The ribbed expanded metal lath in No. 27 had ribs 24 i n - high spaced Z l / 2 in. apart, the weight being 7.9 Ib. per sq. yd. The proportion of the plaster was 1 part Portland cement, 1/10 part hydrated lime and 2y 2 parts lake sand of medium grade of coarseness, all materials being measured by loose volume. The sand had an average moisture content of 3 percent. The thickness of the layers was measured from the inside of the lath. For Nos. 23, 24 and 25, a layer thickness of 1 in. was desired and was attained in Nos. 23 and 25. In No. 24 the layer thickness averaged % in. In No. 26 an attempt was made to place a 2-in. thick layer but this proved impracticable with the given sec- tion using two body coats, an average thickness of V/& in. being finally attained. In No. 27 an effort was made to make a solid covering by pushing the plaster through the lath against the out- side of the column. This succeeded only partly, a broken air space averaging y 2 in. in depth remaining between the covering and the column. For all plaster on metal lath protections the extreme edges of the bracket angles near the top of the column were covered by a single layer 1 in. thick. The coverings were finished by trowelling and floating the sec- ond coat to a smooth surface. 42 SCHEDULE OF TESTS (d) Columns Protected by Concrete The tests with concrete protections are described in Table 3e. Six combinations of fine and coarse concrete aggregates, as used in building construction in four large industrial centers, are included. The aggregate combinations and districts represented are: (1) Rockport granite with Plum Island sand for the Boston, Mass., district; (2) Chicago limestone with Fox River sand, and Joliet gravel with Joliet sand for the Chicago, 111., district; (3) Cleve- land sandstone with Pelee Island sand for Cleveland, O., district; (4) New York trap rock with Long Island sand, and hard coal cinders with Long Island sand for the New York, N. Y., district. The districts were chosen so as to obtain representation for the main groups of rocks that are used as concrete aggregate. The aggregates are further described in Par. 6 of Section V (p. 70). The proportions of the mixtures used were 1 :2 :4 and 1 :3 :5 for the stone and gravel concrete and for the, cinder concrete, 1 :iy 2 'A 1 /* and 1:2:5. The cinders were used unscreened as received except that pieces larger than one inch were crushed to smaller size. Ties consisting of No. 5 (B. & S. gauge) bright basic steel wire were wound spirally around the structural section on vertical pitch of 8 in. The tie was emitted in Test Nos. 28A and 33A in order to determine what effect, if any, it has on the effectiveness of the covering. In No. 46 it was omitted because the latticed section was deemed to afford sufficient support for the outside covering. In No. 47 an attempt was made to place the covering with the tie wire supported on 1-in. T-bars. This proved impracticable on ac- count of the obstruction it made to the flow of concrete, this cover- ing being therefore placed without tie. For the square coverings the thickness was measured, re- spectively, from the face of the flange and from its extreme edge. For the round protecti&ns, Test Nos. 37 and 40, the thickness of covering on the face of the flange was greater than the given nom- inal thickness and that on the flange edge smaller than the given thickness, each by about ^ in. For the concrete, as well as all other full protections, the thickness of covering on the extreme edges of the bracket angles near the top of the column was about one inch. SCHEDULE OF FIRE TESTS 43 TABLE 3e. SCHEDULE OF FIRE TESTS Columns Protected by Concrete Test No. SECTION PROTECTION Thickness, In. Mixture Material 28 2? A 29 30 31 32 32 A 33 33 A Rolled H I 2 2 2 2 2 2 2 4 4 1:2:4 1:2:4 1:2:4 1:2:4 1:2:4 1:2:5 1:2:5 1:2:4 1:2:4 Portland cement Fox River sand Chicago limestone Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Portland cement Joliet sand Joliet gravel Portland cement Pelee Island sand Cleveland sandstone Portland cement Ix>ng Island sand Hard coal cinders Portland cement Long Island sand Hard coal cinders Portland cement Fox River sand Chicago limestone Portland cement Fox River sand Chicago limestone * ^=5=^ T?^ ' j(?pl U ^.' O-.dJ \-' r A' ovs*;-=^- U /2" * Rolled H d ^rr' a/ - 0. . 0.1 o.o. o . . - 1> /2" L ^ ' Rolled H Rolled H Rolled H Rolled H ^^T^-- ^- c 1 p '.1 y A p My-/ ftS*A*&rA : /2' C /2= 3 Z-bar and Plate u v^r^-7-^ '^W vy[^vL^ ( !r /5" V o * o ' ' & , Rolled H *-Vv. |0 ; T . ..'N^i*?^. . o o Q 9 16' Cr 16- *" ~& - o " a ? '---^tr-'o. > I A Rolled H ; ' 1 ' o * 1 o . O . . Q .' o 16' r /6" * NOTE: Ties where used are of No. 5, B. & S. gage, steel wire, wound spirally on a pitch of 8 in. 44 SCHEDULE OF TESTS TABLE 3e. SCHEDULE OF FIRE TESTS Columns Protected by Concrete Continued Test No. SECTION PROTECTION Thickness, In. Mixture Material 31 34A 35 36 37 38 39 Rolled H Rolled H Rolled H 4 4 4 2 4 2 4 1:2:4 1:2:4 1:3:5 1:2:4 1:2:4 1:2:4 1:2:4 Portland cement Plum Island sand Rockport granite Portland cement Plum Island sand Rockport granite Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Portland cement Long Island sand New York trap Portland cement Joliet sand Joliet gravel Portland cement Meramec River sand Meramec River gravel "' >- : i i | : "! o - * . /o Plate and Angle /a 13 4 tt ?J ,, ;or ' Plate and Angle 1 ^ (> \< "c> . |D^K Jl -* " 4. o i *%>' X Q7 a z " Plate and Channel 6 -< ^ V. ~A tt r 1* ^ ' e . i s &,f 5 ev--- '# . Plate and Channel f^f >5 "J 1 l' A '5it 5 < t J NOTE: Wire ties are of No. 5, B. & S. gage, steel wire, wound spirally on a pitch of 8 in. SCHEDULE OF FIRE TESTS 45 TABLE 3e. SCHEDULE OF FIRE TESTS Columns Protected by Concrete Concluded Test No. 40 41 42 43 44 45 46 47 SECTION Latticed Channel Z-bar and piate r I-beam and Channel I-beam and Channel Starred Angle Latticed Angle Bf Round Cast Iron PROTECTION Thickness, In. 2-in. outside rivets. Of*. outside Mixture 1:2:4 :3:5 1:3:5 1:2:4 1:3:5 1:2:4 1:2:4 1:2:5 Material Portland cement Long Island sand New York trap Portland cement Fox River sand. Chicago limestone Portland cement Fox River .sand Chicago limestone Portland cement Pelee Island sand Cleveland sandstone Portland cement Pelee Island sand Cleveland sandstone Portland cement Meramec River sand Meramec River gravel Portland cement Long Island sand New York trap Portland cement Long Island sand Hard coal cinders NOTE: Wire ties where used are of No. 5, B. & S. gage, steel wire wound spirally on a pitch of 8 in. 46 SCHEDULE OF TESTS (e) Columns Protected by Hollow Clay Tile The tests with hollow clay tile protections are given in Table 3f. Five kinds of tile from as many producing regions were used for the coverings. These include two varieties of surface clay tile, one of shale and two of semi-fire clay. They are further described in par. 11 of Sec. V (p. 81). The tile was set in mortar consisting of 1 part by loose volume of Portland cement, 1 part of lime putty, and 4 parts of fine beach or bank sand. The sand had an average moisture content of 4 per- cent. The thickness of mortar between the tile and the flanges of the test columns varied between the different protections from J^ to l l /& in. The thickness of horizontal joints between the tile courses averaged ^ in. where no wire mesh was used, and ^ in. where used. The vertical mortar joints varied in thickness from y$ to 24 in., depending on the design of the covering. The upper tile courses were set out sufficiently to allow the extreme edges of the bracket angles to be covered by a 1-in. thick- ness of tile and motar. Two forms of mechanical ties for the tile were used. One consisted of a No. 12 (B. & S. gauge) iron wire tied around the out- side of each course at the middle, and the other of strips of %-in. wire mesh (diam. of wire 0.046 in.) laid in the horizontal joints and lapped at the corners. The filling inside of the tile, where used, consisted of con- crete or hollow clay tile. The concrete was placed after the tile was set, except in case of No. 60 where the fill was placed and allowed to harden before setting the tile. All protections were tested in the unplastered condition ex- cept those of Nos. 76 and 77. The former was plastered with a two-coat layer of gypsum plaster ^4 ' m - thick. The first coat of about ^-in. thickness consisted of 1 volume part neat fibered calcined gypsum and 3 parts fine lake sand, and the finish coat, 1 volume part neat unfibered calcined gypsum and 2 parts hydrated lime. No. 77 was plastered with lime plaster ^ in. in thickness, the first coat consisting of 1 volume part slaked lime putty and 2^/2. parts of fine lake sand, the finish coat being the same as for No. 76. SCHEDULE OF FIRE TESTS 47 TABLE 3f. SCHEDULE OP FIRE TESTS Columns Protected by Hollow Clay Tile Test No. SECTION Thick- ness of Tile. In. Kind of Tile and Method of Application Filling 48 49 50 50-A 51 51-A 52 53 f o Semi-fire clay, New Jersey district ^-in mortar on flanges Outside wire ties Semi fire clay, New Jersey tiistrict 54 -in mortar on flanges Surface clay, Boston district %-in. mortar on flanges Same as No. 50 Suiface clay, Boston district lH-i fl mortar on fl'anges Outside wire ties Same as No. 51 Ohio shale %-in. mortar on flanges Outside wire ties Ohio shale 1-in. mortar on flanges Outside wire ties No filling No filling 1:3:5 concrete Portland cement Plum Island sand Rockport granite Same as No. 50 1:3:5: concrete Portland cement Plum Island sand Rockport granite Same as No. 51 1:2:5 concrete Portland cement Long Inland sand Hard coal cinders 1:2:5: concrete Portland cement Ixjng Island sand Hard coal cinders en en CD fja a Rolled H ] D ] Q-/3. a a . a c$ CD en c=i < of J r 4 D Rolled H d Tgpa To,; J^n noun! /#' J Plate and Angle Plate and Angle >' 2 2 -i^-ir >* j i /?- j 4 1 4 c Plate and Angle Q c ]|DGDD ISIS D&jfcfeg Angle innn a /6f J Plate and Chanm > 2 CZDC=]CZZ] ]W=sEjwn is ^ 72" J 4 c Plate and Channel r innn ]? '"fn T . .' ' ,/ 1 ' 1 '' Myin C inn a u /6i" J SCHEDULE OF TESTS TABLE 3f. SCHEDULE OF FIRE TESTS Columns Protected by Hollow Clay Tile Continued Test No. 55 56 57 59 SECTION Latticed ' Channel Z-bar and Plate aof- I-beam and Channel I-beam and Channel Thick- ness of Tile, In. Two 2-in. Two 2-in. Kind of Tile and Method of Application Ohio semi-fire clay Outside wire ties Ohio semi-fire clay Outside wire ties Ohio semi-fire clay %-in. wire mesh in hori- zontal joints Surface clay, Chicago district Outside wire ties Surface clay, Chicago district H-jn. mortar on flanges iHii-in. wire mesh in hori- zontal joints Surface clay, Chicago district H-in. mortar on flanges Outside wire ties Filling 1:3:5 concrete. Portland cement Long Island sand New York trap 1:3:5: concrete, Portland cement Fox River sand Chicago limestone 1:3:5: concrete, Portland cement Fox River sand Chicago limestone 1:3:5: concrete, Portland cement Fox River sand Chicago limestone Hollow clay tile, 2 by 12 by 6 in. at at ends 3 by 12 by 6 in. at Hollow clay tile, 2 by 12 by 6 in. at ends 3 by 12 by 6 in. at sides SCHEDULE OF FIRE TESTS TABLE 3f. SCHEDULE OF FIRE TESTS Columns Protected by Hollow Clay Tile Concluded Test No. SECTION Thick- ness of Tile, In. Kind of Tile and Method of Application Filling 60 61 62 63 76 77 t "*~~ ~L 2 2 2 2 4 Ohio semi-fire clay i-i-in. mortar between fill and tile Outside wire ties Ohio semi-fire clay Outside wire ties Porous semi-fire clay, New Jersey district %-in. mortar Outside wire ties Same as No. 62 Ohio shale: Ohio semi-fire clay; semi-fire clay, New Jersey district %-in. mortar on flanges 2^-in. wire mesh in hori- zontal joints Tile covered with a 2-coat. %-in. layer of 1:3 gypsum plaster Semi-fire clay, New Jersey; surface clay, Chicago; surface clay, Boston dis- trict IJ^-in. mortar on flanges ;Hj-in. wire mesh in hori- zontal joints Tile covered with a 2-coat, %-in. layer of 1'2^ lime plaster 1 :2:4: concrete Portland cement Long Island sand New York trap Fill placed before tile was set No filling No filling No filling 1:3:5: concrete Portland cement Fox River sand Chicr>go limestone 1:3:5 concrete Portland cement Fox River sand Chicago limestone 9 1~ i c_ j i_ Latticed . ,r 1 Angle" !I 4 f S: E E Latticed Angle = ff^z | rfT i lr iffi ILJt j/5j /5j - Round Cast Iron /<%S^&. Round Cast Iron \cf^|i/ J Rolled H 15' 1 . o (> 1__JI iLfji 1 15' in na n : I Plate and [ U Angle > [_ |n r*%D! ^&D; ana; h 172 -1 NOTE: The mortar used in setting the tile consisted of 1 part Portland cement, 1 part lime puttj and 4 parrs fine beach or bank sand. 50 SCHEDULE OF TESTS (f) Columns Protected by Gypsum Block The tests with gypsum block protections scheduled in Table 3g consist of two with 2-in. and three with 4-in. solid block. The material was supplied from two factories, one located in the Mid- dle Western section of the country and the other in the Eastern section. The proportion of the mortar used for setting the block was 1 part by volume of neat unfibered calcined gypsum and 3 parts by volume of fine lake sand. The latter as used had a moisture content of about three per cent. In Nos. 64 and 65 the blocks were tied with No. 22 corrugated galvanized iron strips ^4 in - wide by 6 in. long placed in the horizon- tal joints, and across all vertical joints, one over each joint in the 2-in. covering and two over each joint in the 4-in. covering. In Nos. 66, 67 and 67 A strips of woven wire (0.046 in. wire diam.) of 3/^-in. mesh were laid in the horizontal joints over all vertical joints. The size of the strips for the 2-in. protection was 2 by 14J4 in. and for the 4-in. protections, 3*^ by I6y 2 in., the strips being laid so the outer edges were % in. from the surface of the covering. The thickness of the horizontal joints averaged J/ in. between the 2-in. blocks and ^4 m - between the 4-in. blocks. The vertical joints were about ^ in- thick. The space between the blocks and column flanges was fairly filled with mortar as the blocks were set. The remain- ing space inside of the blocks was filled with gypsum block set in mortar in the case of Nos. 64 and 65. For the other gypsum protec- tions the filling material consisted of 1 part by volume of neat un- fibered calcined gypsum, 1 part fine lake sand, and 4 parts gypsum blocks broken to maximum size of 2 in., the whole being mixed to wet consistency. The methods of tying the blocks and filling within them con- form with the recommendations of the manufacturers by whom they were supplied. SCHEDULE OF FIRE TESTS 51 TABLE 3g. SCHEDULE OF FIRE TESTS Columns Protected by Gypsum Block Test No. 64 65 67 SECTION Rolled H t -17- Plate and Channel -121- Latticed Channel Rolled H 67-A Rolled H '. .^.'D Thick- Block, In. Kind of Gypsum and Method of Application Western gypsum (solid) M-in. mortar on flanges Corrugated wall ties in horizontal joints Western gypsum (solid) 1-in. mortar on flanges Corrugated wall ties i horizontal joints Eastern gypsum (solid) %-in. mortar on lattice 2|-in. wire mesh in horizon- tal joints Eastern gypsum (solid) %-in. mortar on flanges 3/^-in. wire mesh in horizon- tal joints Same as No. 67 Filling Hollow Western gypsum block Solid Western gypsum block 1:1:4, Calcined gypsum Fine lake sand Broken gypsum block 1.1:4, Calcined gypsum Fine lake sand Broken gypsum block Same as No.67 NOTE: The gypsum blocks were set in mortar consisting of 1 part by volume of neat unfibered calcined gypsum and 3 parts fine lake sand. 52 SCHEDULE OF TESTS (g) Columns Protected by Brick The two tests with brick protection are described in Table 3h. The proportion of the mortar was the same as that used for the clay tile protections. In placing the brick no metal ties were used, the brick being in each case set so as to obtain the best bond possible with the given design of covering. The thickness of the horizontal joints averaged J^ in. and that of the vertical joints varied from to m - TABLE 3h. SCHEDULE OF FIRE TESTS Columns Protected by Brick Test No. SECTION Thick- ness of Brick, In. Kind of Brick Filling 68- 69 Rolled H hH I f 2M 3M Chicago common brick Bet on edge and end iHs-in. mortar on flanges Chicago common brick laid flat Hi -in. mortar on flanges Chicago common brick Chicago common brick i uu /3 J +\ 1 Rolled H 3E - /&' J NOTE: The mortar consisted of 1 part Portland cement. 1 part lime putty and 4 parts bank sand. SCHEDULE OF FIRE TESTS 53 (h) Reinforced Concrete Columns These are scheduled in Table 3i and details of design are given in Figs. 8 and 9 (p. 30-31). A thickness of -2 in. of the concrete next to the surface of the column is taken as a protective covering for the concrete and steel within it, and is not included in the given effective areas. TABLE 3i. SCHEDULE OP FIRE TESTS Reinforced Concrete Columns Effective Length, 12 ft. 8 in. Test No. 70 72 73 74 75 SECTION Square Vertically Reinforced Square Vertically Reinforced Round Vertically Reinforced Round Vertically Reinforced Hooped Reinforced Hooped Reinforced Mix 1:2:4 1:2:4 1:2:4 1:2:4 1:2:4 1:2:4 Material Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Portland cement Fox River sand Chicago limestone Portland cement Long Island sand New York trap Effective Area, Sq. In. Concrete, 140 Steel, 4. 00 Same as No. 70 Concrete, 127 Steel, 6.00 Same as No. 72 Concrete, 129 Steel. 3.38 Same as No. 74 Reinforcement, Percent of Effective Area Vertical, 2.78 Lateral, 0.14 Same as No. 70 Vertical, 4.52 Lateral, 0.13 No. 72 Vertical, 2.54 Lateral, 0.99 Same as No. 74 A depth of 2 in. all around deducted from the gross section for fire protection. 54 SCHEDULE OF TESTS (i) Timber Columns The schedule of timber columns is given in Table 3j and de- tails of columns and bearings are shown in Fig. 10 (p. 33). Th^ tests include two species of timber, each tested 'with two types of bearing details. No. 78 was protected by a single layer of plaster on metal lath, the details of application being the same as for the protections listed in Table 3d. No. 80 was covered with gypsum wall board y% in- thick nailed into the timber at the corners with No. 4 lathing nails on 2-in. centers, and finished with kalsomine. The other timber columns were tested unprotected. TABLE 3j. SCHEDULE OF FIRE TESTS Timber Columns Effective Length, 12 ft. 8k in. Test No. 78 79 80 SPECIES SECTION Longleaf lit pine | 1_ wl- 15" I I*' J Longleaf pine 1 ] II* Longleaf pine Douglas fir Douglas fir I ni" i J Protection of Column and Cap One 2-coat layer of Portland cement plaster, 1 in. thick, on woven wire lath, iHi-in. mesh, f-in. air space Plaster consisted of 1 part Portland cement. 1/10 part hydrated lime. 2\4 parts coarse lake sand Unprotected One thickness of %-in. gypsum wall board with metal corner beads, nailed to column Unprotected Unprotected Unprotected Bearing Details Cast iron cap and pintle Cast iron cap and pintle Steel plate cap and 8 in, long timber strut. Steel plate cap and 6 in long timber strut Cast iron cap and pintle Steel plate cap and 18 in. long timbei strut SCHEDULE OF P. RE AND WATER TESTS 55 3. SCHEDULE OF FIRE AND WATER TESTS This series was introduced in order to determine the effect on coverings and columns of the impact and sudden cooling produced by hose streams applied to them when in a highly heated condi- tion. In order to introduce all of the materials used in the fire test series with a minimum number of tests, two or three kinds of mate- rial of a given class were applied in each test. (a) Columns Protected by Concrete The fire and water tests with concrete protections are scheduled in Table 4a. Three kinds of concrete were applied to each column. In this and succeeding tables the concrete is distinguished by the name of the coarse aggregate, the sand used with each being the same as in the combinations given above in par. 2d (p. 42). The metal tie in the covering is the same as for the correspond- ing protections in the fire test series. In No. 102 the tie is omitted. (b) Columns Protected by Hollow Clay Tile These coverings are also placed in three sections (Table 46) with one of the varieties of tile used in the protections of the fire test series in each section. The proportions of the mortar and size of metal ties are the same as for the corresponding protections of the fire test series. * (c) Columns Protected by Gypsum Block The two kinds of gypsum with the method of application pecu- liar to each, described in par. 2f. (p. 50) of this section, are employed in the two tests (Table 4c). The filling for both consists of a 1 :1 :4 mixture by volume parts of calcined gypsum, fine lake sand, and broken gypsum block, mixed to wet consistency. (d) Plaster on Metal Lath Protection The protection of this type included in the fire and water series is described in Table 4d. The metal lath, proportion of the plaster and method of application are the same as for the corresponding protections of the fire test series. (e) Reinforced Concrete Columns One column of each type is included in this series. Details of concrete and reinforcement are given in Table 4e. (f) Unprotected Cast Iron Columns Two duplicate columns are listed in Table 4f. They are ver- tically cast and have bearing details as shown in Fig. 6 (c) (p. 27). 56 SCHEDULE OF TESTS . TABLE 4a. SCHEDULE OF FIRE AND WATER TESTS Columns Protected by Concrete Test No. SECTION PROTECTION Thickness, In. Mixture *Kind of Concrete 101 102 103 104 Rolled H 2 2 4 2 1:2:4 1:2:4 1:2:4 1:2:5 1:2:4 1:2:4 - . -1 Chicago limestone New York trap Joliet gravel ' New York trap Joliet gravel Chicago limestone . New York trap New England granite Chicago limestone Hard coal cinders Cleveland sandstone New York trap . o'J^f ""^x^O * jy ;>;); cT*^-=- =="-4r'o l2 -' * Rolled H D ' a ' 6 1 ' . ' $ . * I 12' J Plate and Angle ' >?r m *\/J 1 i' i' i h-'? Plate and Angle i m m f T-J *Three kinds of concrete were used on each column, placed in three vertical sections in the orde named, from top to bottom of column. NOTE: Ties where used are of No. 5, B. & S. gage, steel wire, wound spirally on a pitch of 8 in. SCHEDULE OF FIRE AND WATER TESTS TABLE 4b. SCHEDULE OF FIRE AND WATER TESTS Columns Protected by Hollow Clay Tile 37 Test No. SECTION Thick- ness of Tile, In. *Kind of Tile and Method of Application Filling 105 106 107 Plate and Angle 2 2 4 Surface clay. Boston district; semi-fire clay, N. J. district; Ohio shale %-in. mortar on flanges Outside wire ties Ohio semi-fire clay; surface clay, Chicago district; Ohio semi-fire clay %-in. mortar on flanges Outside wire ties on upper half %-in. wire mesh in horizontal joints in lower half Ohio shale; semi-fire clay, N. J. district; surface clay, Boston district 1-in. mortar on flanges Outside wire ties on upper half %-in. wire mesh in horizontal joints in lower half No filling 1:3:5 concrete, Portland cement Long Island sand Chicago limestone No filling or J Plate and Angle I 1 i f^^f n } n 12" * ^ Plate and Channel DyJJn O5 in In ! -(6t - 'Three kinds of tile were used on each column, placed in three vertical sections in the order named from top to bottom of column. TABLE 4c. SCHEDULE OF FIRE AND WATER TESTS Columns Protected by Gypsum Block Test No. SECTION Thick- ness of Block, In. *Kind of Gypsum and Method of Application Filling 108 109 Rolled 2 4 Western gypsum (solid); East- ern gypsum (solid) 34 -in. mortar on flanges Corrugated wall ties in hori- zontal joints in upper half %-in. wire mesh in horizontal joints in lower half Eastern gypsum (solid); West- ern gypsum (solid) %-in. mortar on flanges ^-in. wire mesh in horizontal joints in upper half. Corru- gated wall ties in horizontal joints in lower half 1:1:4 Calcined gypsum Fine lake sand Broken gypsum block 1:1:4 Calcined gypsum Fine lake sand Broken gypsum block B \\ j .' o V ?J S3s^ tf.'-i:i''^VJ /# J Rolled H m >. - o 0". L I7k" J *Two kinds of block were used on each column, placed in two vertical sections in the order named from top to bottom. 58 SCHEDULE OF TESTS TABLE 4d.-SCHEDULE Or FIRE AND WATER TESTS Column Protected by Plaster on Metal Latli Test No. SECTION PROTECTION T r-6*"-^ Two 2-coat layers of Portland cement plaster; inner layer Y% in. thick, on woven wire lath; outer layer 1 in. thick, 110 Plate and 91 Angle i \ tf on expanded metal lath. M-in. air space between layers. Proportion of plaster, 1 part Portland cement, 1/10 part hydrated lime, 2^ parts coarse lake sand I2i. TABLE 4e. SCHEDULE OF FIRE AND WATER TESTS Reinforced Concrete Columns Effective Length, 12 ft. 8 in. Test No. SECTION Mix- ture *Kind of Concrete **Effective Area, Sq. In. Reinforcement, Percent of Effective Area Ill 112 113 j:?*i IO{\2& 1:2:4 1:2:4 1:2:4 Chicago limestone Meramec R. gravel Chicago limestone Chicago limestone Meramec R. gravel Joliet gravel New York trap Meramec R. gravel Rockport granite Concrete, 140 Steel, 4.00 Concrete, 127 Steel, 6.00 Concrete, 129 Steel, 3.38 Vertical, 2.78 Lateral, 0.14 Vertical, 4.52 Lateral, 0.13 Vertical, 2.54 Lateral, 0.99 Square Vertically Reinforced |LJ^<| U 16' A Round Vertically Reinforced ($$?$ r '-/"Bars- / y Hooped Reinforced H *Three kinds of concrete were used in each column, placed in three sections in the order named, from top to bottom of column. **A depth of 2 in. all around deducted from the gross section for fire protection. SCHEDULE OF FIRE AND WATER TESTS 59 TABLE 4f. SCHEDULE OF FIRE AND WATER TESTS Unprotected Cast Iron Columns Effective Length, 12 ft. &A in. Least Test No. SECTION DETAILS Nomi- nal Area, Radius of Gy- ration, 1 r Sq. In. r In. 114 Round Cast Iron, Vertically cast ^^^rrrrjfc Ends not restrained 14.45 2.38 63.2 115 Round Cast Iron, ^^Krtq: / Vertically cast U "7g' Ends not restrained 14.45 2.38 63.2 PLACING OF COVERINGS AND COLUMNS Fig. 11. Forms and staging for placing concrete. IV. PLACING OF COVERINGS AND CONCRETE COLUMNS The work was planned so as to reproduce as nearly as possible the conditions obtaining in building construction in point of meth- ods of application and workmanship. This was done to make the results of the tests applicable without undue allowance for differ- ences that otherwise might be deemed to exist between the test sample and a similarly constructed member in a building. 1. CONCRETE PROTECTIONS AND COLUMNS (a) Forms and Staging The wood forms were made of 1^-in. yellow pine planks with clamps spaced about two feet apart vertically. The round columns and coverings were cast in metal forms made of No. 12 (0.1094 in. thick) sheet steel, the forms being made into halves which were bolted together through angles riveted on their edges. The form was supported within a staging extending to the top of the test column proper, the floor of the staging being used as a platform from which the concrete was placed and on which subse- quently the form for the column head or column head protection was erected. A view of the staging with column forms in place is shown in Fig. 11. (b) Method of Proportioning The proportions were based on volume parts of the materials as taken from the bins except that the Portland cement was meas- ured in the original package, one bag containing 94 Ib. of cement being taken to be one cu. ft. The sand and stone were measured in deep steel wheelbarrows in two or three cu. ft. portions, the volume for each being determined by striking off the top with a board cut to the required shape (Fig. 12). In some tests where the mixtures appeared lean in sand, two or three shovelfuls of sand were substituted for an equal amount of stone. (c) Mixing and Placing The concrete was mixed in a motor-driven Marsh-Capron batch mixer having a capacity of 6 cu. ft. of mixed concrete. The mate- rials were charged into the mixer in the following general order, subject to minor variations introduced by the different men in charge 61 62 PLACING OF COVERINGS AND COLUMNS CONCRETE PROTECTIONS AND COLUMNS 63 of the mixing: (1) 2 cu. ft. coarse aggregate, (2) 2 or 3 cu. ft. of sand, (3) one bag Portland cement, (4) 2 or 3 cu. ft. of coarse ag- gregate, (5) water. Before admitting the water the materials were mixed dry for a period varying from J4 to J^ min., the total time of mixing being limited to lJ/2 min. as a maximum and 1 min. as minimum. The water was measured by means of a gage glass and scale, the former connecting with a vertical measuring tank placed above the mixer (Fig. 12). The concrete was discharged into wheelbarrows, which were raised to the platform of the staging for discharge into the forms. The concrete was spaded along the inside of the form and the latter was tapped with a hand hammer to assist in obtaining a good con- crete surface. To obtain workmanship comparable with that on field placed concrete, several experienced men connected with local construc- tion companies were at different times placed in charge of the mix- ing and placing, about one-half of the total number of concrete coverings and columns being thus placed. The methods thus in- troduced were followed in the mixing and placing of the concrete for the remaining columns. 2. PLASTER ON METAL, LATH PROTECTIONS (a) Placing of Lath For Test No. 23 the lath for both the outer and the inner layer was supported on round bars held upright by iron clips made from Y% by 1 in. flat bars and secured to the structural steel section. This method proved very cumbersome and the lath for the other steel columns was supported on ^ by ^ m - channels held in ver- tical position by wire ties. The high-ribbed lath was supported directly on the metal. The lath was placed around the column in horizontal courses with laps of about three inches. Horizontal joints between sheets had generally shorter laps. All laps were wired with No. 18 wire ties placed 3 to 6 in. apart vertically and one on the middle of each side of the horizontal joints. (b) Applying the Plaster The plaster coats were of the maximum thickness practicable with the given mixture of plaster. The first coat of a layer was allowed to set two to three days before applying the second coat. The lathing and plastering were done by experienced men ob- tained through a local plastering contractor. 64 PLACING OF COVERINGS AND COLUMNS HOLLOW CLAY TILE AND BRICK PROTECTIONS 65 3. HOLLOW CLAY TILE AND BRICK PROTECTIONS (a) Proportioning of Mortar The mortar was proportioned by volume parts of loose mate- rials. The proportion used was 1 part Portland cement, 1 part stiff lime putty (slaked lump lime) and 4 parts fine bank or lake sand. (b) Placing of Tile and Brick The coverings were detailed in advance, and tile of the re- quired size was supplied when possible. All cutting of tile and brick was done on the job with the hammer or trowel. . A view of tile and gypsum block protections under construction is shown in Fig. 13. The work was done on a contract basis by a mason contractor and it is thought that the workmanship obtained approximates that secured in good building practice. (c) Placing of Concrete Filling Where concrete filling was used the tile was held in place by- clamping both ways every 2 ft., boards being placed along the protection inside of the clamps. The filling, which in all cases was confined to the space between the tile and the structural section, was placed from the platform of the staging shown in Fig. 11, the whole column being filled in one continuous operation. The clamps effectively held the tile against the pressure of the wet fill and very few mortar joints were broken from this cause. 4. GYPSUM BLOCK PROTECTIONS (a) Proportioning of Mortar The proportion of mortar used, 1 :3, neat unfibered calcined gypsum and fine lake sand, was the richest mixture that would work satisfactorily under the trowel, the materials being measured by loose volume. (b) Placing of Block The blocks were cut from standard size partition blocks with a hand saw, the resulting pieces being generally all used either in the covering or filling. The mortar joints in the covering and be- tween the blocks and flanges of the test column were well filled. (c) Placing of Filling Where wet filling was used, the dry materials were first turned three times by hand and then mixed with water in small batches. The filling was placed as the blocks were laid up, two courses being generally filled at one time. The placing and filling of the gypsum coverings was done by a fireproofing contractor employing men experienced in handling the given material. 66 PLACING OF COVERINGS AND COLUMNS 5. METHOD OF STORAGE Normal air storage was used for all columns and for the greater number of auxiliary test specimens. The test columns were stored in the testing room, the tem- perature of which during the summer months was, about the same as that of the outside air and varied during the winter months from 5 to 25 C. (41 to 77 F.). The auxiliary test specimens consisting of 8 by 16-in. concrete cylinders and 2-in. mortar cubes made from the material of the coverings as placed were arranged in tiers and stored near the test columns. In some laboratory tests with mortar the briquettes and cubes were stored for periods in damp closet or water as stated in Sec. V (Table 28, Appendix D, p. 371). V. AUXILIARY TESTS OF MATERIALS The results of the auxiliary tests give information on the phys- ical, chemical and thermal properties of the materials used in the columns and coverings. Where generally accepted standards in the form of specifications exist, some comparable measure of qual- ity, is thereby afforded. For the majority of the materials no gen- eral specifications have as yet been developed and their representa- tive character must be determined by the extent of their use and the methods employed to obtain material of average quality. The large number of tests of concrete, mortar and plaster give important information on their properties and variability as made under conditions approximating those obtaining in building con- structon. 1. TESTS OF STRUCTURAL, BAR AND WIRE STEEL Results of tension tests are given in Tables 5 and 6 (Appendix D .* The specimens of structural steel, about seven inches long and y% to J/ in. wide, were cut before test from the upper enlarged portion of the column section by drilling and sawing. They were finished to uniform width over a gage length of 2 in. Tests of bar steel were made on the full sections of the bars used except as noted in Table 5 (p. 351). Specimens for hardness tests were taken where tension speci- mens were difficult to obtain and results of tests are given in Table 7 (p. 353). Chemical analyses of structural and rivet steel are given in Table 8 (p. 354). The column steel was of the grade generally used for struc- tural purposes. Of the 77 structural steel columns used in the tests, 36 were donated by the manufacturers and 22 were bought from the same sources, with no specifications as to quality of ma- terial. The steel for the remaining columns, which were purchased at a later date, was specified to conform with the specifications for structural steel for buildings of the American Society for Test- ing Materials. Correspondence with the manufacturers indicates that all of the steel was made by the open-hearth process and that with the exceptions above noted, the specifications followed were *The tabular matter for this section is placed in Appendix D (p. 349-379). 67 68 AUXILIARY TESTS OF MATERIALS Manufacturers' Standard Specifications for Steel for Railway Bridges or for Medium Open-Hearth Steel, tensile strength 55,000 to 70,000 Ib. per sq. in. A few of the test results were above or below the specification limits by 10 percent or less, a variation that may be allowable, considering that most of the test specimens secured were smaller than the standard size. The metal for the reinforcing bars was specified to conform with specifications for billet-steel concrete reinforcing bars of the American Society for Testing Materials, structural grade. The spiral hooping was of hard drawn wire of high tensile strength (87,400 Ib. per sq. in.). 2. TESTS OF CAST IRON Results of transverse and tension tests are given in Table 9 (p. 354). The specimens of the horizontally cast columns were cut from the projecting flanges in the upper three feet or head of the col- umn. Those representative of the metal in the vertically cast iron pipe columns, 10 A, 114 and 115, were cut from a duplicate column. Results of chemical analyses of the iron in the horizontally cast columns are given in Table 10 (p. 354). The iron for the horizontally cast columns was of gray foun- dry pig with admixture of machinery casting scrap. The mixture used for the cast iron pipe columns and caps was the same as that regularly used in the manufacture of cast iron water pipe. The following analyses of the mix were furnished by the makers: Horizontally Vertically Cast Cast Columns Columns Caps Silicon 2.04 1.60 1.70 Manganese 0.45 0.34 0.32 Combined carbon 0.72 .... .... Phosphorus 0.714 .... Sulphur 0.108 0.081 0.060 For the iron in the horizontally cast columns, the analyses and test results indicate conformity with accepted specifications for gray-iron castings of medium weight. For the vertically cast col- umns, tests of specimens cut from one end of the duplicate column gave transverse and tension values about equal to the specification limits and those of specimens cut from the other end gave values lower by about 15 percent. TESTS OF PORTLAND CEMENT * 69 3. TESTS OF PORTLAND CEMENT Tests of the Portland cement used in the columns and cover- ings were made by the Washington and Pittsburgh laboratories of the Bureau of Standards and by the R. W. Hunt Company. The results are given in Tables 11 to 13 (p. 355-357). Sample Nos. 1 to 5 and B-l and B-2, Table 11, H-l to H-6, Table 12, and H-l to H-3, Table 13, were all from the mill shipment received in April, 1916. Sample Nos. H-7 and H-8, Table 12, were of a later pur- chase of the same brand as the original mill shipment. Sample No. 12, Table 11, was of the Portland cement used in rilling the pipe column of Test No. 12. All samples were individual sack samples taken from the portions of the shipment used at the given time. The time of setting was determined with the Gillmore needles in all tests. Other details of the tests conformed with the speci- fications published by the American Society for Testing Materials, 1916. As based on average results, the tests indicate conformity with the given specifications within the pertaining limits and tol- erances, excepting the test of sample No. 12. The latter gave low results in points of fineness and 7-day tensile strength. 4. TESTS OF SAND The chemical and physical properties of the concrete and finer sands are given in Tables 14 to 17 (p. 357-359). The specific gravity was determined by measuring the volume of benzine displaced by a given dry weight of sand in a Le Chate- lier apparatus. The weight per cu. ft. is that of the loose dry sand poured into the measure without shaking or bumping and leveled off even with its top. The weight of the dry contents of a cubic foot of the sand as used on the work was somewhat less than that given in the tables, due to the moisture contained, which caused it to assume greater bulk than in the dry condition, the difference being about ten per- cent with coarse sand of 3 percent moisture content. With the finer sands the decrease in weight was about 25 percent as caused by a moisture content of 4 percent. The percentage of computed voids was taken equal to the fol- lowing relation of values, 10Q / Weight per cu. ft. (dry) \ V Specific grav.X weight of cu. ft. of water/ The granular analysis gives percentages by weight passing the given sieve openings. 70 AUXILIARY TESTS OF MATERIALS 5. TESTS OF COARSE CONCRETE AGGREGATES Chemical analyses and physical properties of the broken stone, gravel and cinder used for concrete aggregate are given in Tables 18 and 19 (p. 359). The physical properties were determined according to the methods given for tests of sand, except that apparent specific grav- ity was determined in water in a graduated vessel on the saturated aggregate, and was taken as the ratio of the dry weight to that of the water displaced. 6. SOURCE AND CLASSIFICATION OF CONCRETE AGGREGATES The sands and coarse aggregates used for concrete were ana- lyzed for mineral composition and their chief constituents are given in Table 20 (p. 360). Further information on their mineral compo- sition, geological origin, geographic location and the method of preparing them for commercial use are given in the following descriptions. (a) Fox River Sand. This sand was obtained from a sand and gravel deposit about three miles east of Elgin, 111. After crushing of the oversized gravel, the whole is washed and screened to size. The grade is known in the Chicago market as coarse "torpedo" sand, the general maximum size of grains being J4 i n - It is clean and very sharp, only 15 percent of the grains being rounded. The sand is of glacial origin and its principal mineral con- stituents are, calcite and dolomite, 44 percent; quartz and chert, 39 percent. Ferro-magnesians, chiefly biotite, pyroxene and horn- blende constitute 4 percent. No free clay matter was present, al- though about 2 percent of hydrous aluminum silicates were con- tained in the calcite and dolomite. (b) Joliet Sand. This is a clean, sharp, glacial sand obtained from a sand and gravel deposit at Rockdale, 111., the method of preparation and grading being the same as for Fox River sand. The chief mineral constituents are, calcite and dolomite, 47 percent; quartz, 42 percent; feldspar, chiefly orthoclase (KA1S 3 O 8 ), 7 per- cent; ferro-magnesians, chiefly as biotite, mica and hornblende, 3 percent. . (c) Meramec River Sand. This sand is obtained incidentally to screening and washing of gravel dredged from the bed or banks of the Meramec River at Drake, Mo. It consists almost wholly of quartz and chert grains formed from sandy chert by rolling in the stream bed. A small amount of calcite (one percent) is present CLASSIFICATION OF CONCRETE AGGREGATES 71 as a coating on some of the grains. The quartz grains are fully rounded, while the chert is partly rounded or subangular. (d) Long Island Sand. This sand was obtained from banks near Roslyn, Long Island, N. Y., and was screened and washed. It is a glacial sand formed from the crystalline rocks of New England. The principal constituents are quartz and feldspar, with minor amounts of ferro-magnesians, slate, magnetite and cinders. The cin- ders are not an original constituent of the sand. The sand is clean, sharp and angular, the grains showing little rounding. (e) Pelee Island Sand. This sand was dredged by boat from the bottom of Lake Erie, at Fish Point, Pelee Island, Ontario. It is of glacial origin with sharp and angular grains that show almost no rounding. Of the mineral constituents, calcite and dolomite constitute 32 percent, chert and quartz, 51 percent. Clay is present to the extent of 4 percent, of which about one-half is free clay matter and the rest shale. (f) Plum Island Sand. This sand was dug on a beach at Plum Island on the Massachusetts coast and was not screened or washed. It is of glacial origin, although much modified by ocean waves and currents. About 50 percent of the grains have been worn to a sub- angular condition and about 3 percent are well rounded. It is fine grained and contains no free clay material, the mineral composition being otherwise closely identical with that of the Long Island sand. (g) Chicago Limestone. The stone, which was crushed to nominal ^-in. size, was quarried at Gary, Indiana, from a ledge of the Niagara formation. It is a true dolomite (calcium magne- sium carbonate), carrying a moderate amount of clayey impurities. (h) Joliet Gravel. This is obtained from the same source as Joliet sand. It is a glacial gravel, consisting largely of limestone pebbles, of which 20 percent are rounded and 60 percent subangu- lar or partly rounded. Mineralogically the composition is 86 per- cent dolomite, containing about 5 percent clayey impurities ; 5 percent quartz in the form of sandstone and quartzite; 2 percent quartz, 5 percent feldspar and 2 percent ferro-magnesian silicates as pebbles of granite, gabbro and other basic igneous rocks. (i) Meramec River Gravel. The pebbles consist almost en- tirely of chert, an amorphous form of silica, containing a variable amount of water in chemical combination. In the sample exam- ined, 85 percent of the pebbles showed no trace of an earlier struc- ture, 4 percent were sandstone replacements, 9 percent were lime- stone replacements and 2 percent had once been shale. The gravel is colored brown with limonite (2Fe 2 O 3 . 3H 2 O). 72 AUXILIARY TESTS OF MATERIALS (j) New York Trap Rock. This was quarried at Haverstraw, N. Y., from the northern end of the sill of diabase which extends along the western shore of the. Hudson River from this point to Staten Island, forming the Palisades of the Hudson. It is an. in- trusive igneous rock of finely crystalline texture. Of the minerals present, feldspar, chiefly plagioclase (Ca A1 2 Si 2 O 8 ), with some al- bite feldspar (NaAISi 3 O 8 ), constitute 71 percent; ferro-magnesians as augite, 19 percent, and as olivine, 7 percent. In addition to 2 percent of magnetite (Fe 3 O 4 ), there are present scattered crystals of quartz (SiO 2 ) and apatite [Ca 5 F (PO 4 ) 3 ]. (k) Rockport Granite. This stone was quarried at Rockport, Mass., and is sometimes known as Cape Ann granite. It is an in- trusive igneous rock that crystallized under great pressure from a fused condition. The mineral composition is 59 per cent feldspar, chiefly orthoclase (KA1 Si 3 O 8 ) with some albite (NaAlSi 3 O 8 ) ; 35 percent quartz; 5 percent ferro-magnesian silicate as hornblende [(Fe, Mg) SiOJ. The feldspars show slight alteration to kaolin and chlorite. The quartz contains many tiny cavities filled with gases and water occluded when the rock was formed. (1) Cleveland Sandstone. The stone was quarried at Amherst, Ohio, and geologically is known as Berea sandstone or Berea grit. It is a pure sandstone, 98 percent consisting of subangular grains of quartz. (m) Hard Coal Cinders. This is an anthracite cinder repre- sentative of the product used for cinder concrete in New York, N. Y. It consists largely of a porous fused mass of basic silicates, apparently high in lime and magnesia and low in iron. There is present about 10 percent of unburned coal and 5 percent unfused ash - 7. TESTS OF CONCRETE The quality of the concrete secured is thought to represent that of field placed concrete as nearly as it can be conveniently du- plicated under laboratory conditions. The method used for pro- portioning the dry materials was more accurate and the time of mixing longer than now generally obtain on construction work. The range of consistency resulting from the method employed for mixing the concrete is deemed to be representative of current field conditions. Where concrete is properly placed in large building members, its properties are probably more uniform than as given by tests of the relatively smaller cylinders, being, for a given mix- ture and consistency, more nearly the average values obtained in the tests. TESTS OF CONCRETE 73 (a) Test Specimens Four cylinders of 8-in. diameter and 16-in. length were molded of the concrete mixed for each concrete covering, filling or column. Cylinders were also taken of the concrete in the head protections of some of the columns where the method of mixing had been modified so as to give information on the effect of a lower water content and of a longer mixing period. The molds were of cast iron with machined base plates. After the concrete had set and before removal of the molds, the cylin- ders were capped with a plastic mixture of Portland cement and calcined gypsum applied even with the top of the molds by means of a finished iron plate, which remained in place until the mixture had set. In molding, care was taken to obtain the same consis- tency of concrete in the cylinders as in the column. Except for spading with a thin tool near the surface, the concrete was not puddled or tamped in the mold. 14. Concrete cylinder after test. 74 AUXILIARY TESTS OF MATERIALS (b) Percent Water in Concrete Mixture The water introduced in mixing was measured at the mixer and for all but the first 15 columns covered, that present in the aggregates was determined from samples taken on the day the con- crete was mixed. The dry weight in pounds per cubic foot of the ag- gregates as used was determined in a number of separate tests with each aggregate in which the same methods of filling the measures were used as were employed in proportioning materials for the con- crete. The net weight per bag of Portland cement was found to be very nearly 94 pounds. The water content of the mixture is the sum of the water introduced and that contained in the aggre- gates, and in the tables and diagrams is expressed as a percentage of the total dry weight. While the above method gives a fair comparison, in point of consistency, of concrete made from the same aggregate, the com- parison between those of different aggregates is less direct, due to differences in specific gravity and absorption. (c) Testing of Concrete Cylinders Two cylinders of each set were tested in compression at the age of four weeks and two at the time the corresponding column was tested. In the case of the latter, the compressive load was applied by increments of about 10,000 pounds and the deformation measured over a 10-in. gage length by means of an Ames dial gage mounted in a pivoted frame (Fig. 14)'. The results of tests on con- crete mixed for the protections and columns are given in Table 21 (p. 361) and those of the concrete in some of the head protections in Table 22 (p. 365). (d) Compressive Strength of Concrete The diagrams in Figs. 15 and 16 give the average and range of compressive strength of the cylinders taken from the concrete mixed for the columns, their covering and filling. In Figs. 17 and 18 the general effect of consistency on compressive strength is shown. Herein are also included the tests (Table 22) made to study the effect of a lower water content. Fig. 19 gives a compari- son of the strength of concrete mixed for one minute and for two minutes. The mixtures having a water content of 9 to 11 percent were of quaking or mushy consistency, the drier ones being discharged from the mixer with considerable difficulty. The higher water percentages (12 to 15) represent varying degrees of fluid consis- tency. The restricted space in which some of the concrete was placed made fluid or semi-fluid consistencies necessary in order to TESTS OF CONCRETE 75 secure proper placement, although beyond the point where water collects above the concrete after discharge, little is gained in this particular by the excessive use of water. For a given consistency the cinder, and to less extent, the sandstone, required a larger amount of water than the other aggregates due to greater absorp- tion. CL o O 3500 3000 2500 1500 (0 -i 1000 500 Number of Tests . Number of II 8 25 II 20 5 5 118 ^5 II i Test^ 5 5 i A { I i Maximum ^jcfx-X^* t ^&^<^' X 3( 4 > i i 4 ( ^ > I 1 ( i^ -' /Average ( ( r p -- ** ' i Minimum < { h- - ( - - i I 3 f. 29 29 28 28 30 27 491 460455462471 488 458 werage Age in Days Average Age in Days Fig. 15. Average and range of compressive strength of 1:2:4 and 1:2:5 concrete. 76 AUXILIARY TESTS OF MATERIALS 2500 000 ? t 1500 1000 Number of Tests Number of Testa 8 5 2 16 8521 I 1 i < 4 dstoQ? 4 roaU=^ "1 ' I -^ > 3( ~~ * ^* i^rAn"^^ w i 29 29 29 29 497 430 459 476 Average Age in Days Average Age In Days Fig. 16. Average and range of compressive strength of 1:3:5 concrete. For the concrete in the columns and coverings (Table 21) the amount of water introduced was determined by the man in charge of the mixing and placing of concrete for the given column, the water for the first batch being added by increments until the de- sired consistency was attained. For the concrete in the head pro- tections (Table 22) the amount of mixing water necessary for any desired total moisture content was generally predetermined, know- ing the dry weight of the aggregates employed and their moisture content at the given time. TESTS OF CONCRETE 77 2OOO 1500 > 1000 500 IO D Water in Mixture, Percent of Weight of Total Dry Materials Fig. 17. Effect of consistency on compressive strength of concrete. Average age, 28 days. sf 3000 i 8500 -Q 5 2000 2 S w 1500 a >^ & o o oS^ ^^ R ^ k ^ ^ + ^ X ' off N^ "^^O . ? s / - + X . ^sQ ^s ^ ^ * x / ^ L 5 ^ v > ^ s . x^ ; . ^% N. O 1 500 OK4 crScaqoIlmestone 35 Chicago Limestone -HM New WK Trxjp xte4 Rochport Granile Ote4Meramec RGravel O ( ' X % V * H D o 9 Water in Mixture, Percent of Weight of Total Dry Materials Fig. 18. Effect of consistency on compressive strength of concrete. Average age, 490 days. 78 AUXILIARY TESTS OF MATERIALS S" 4000 Q. O O 300O 2000 E 1000 Each point is the avera5e of two tests Time of Mixing in Minutes ). Effect of time of mixing on compressive strength of concrete. (e) Modulus of Elasticity of Concrete A comparison of values for 450, 650 and 850 Ib. per sq. in, is given in Fig. 20 as obtained from Table 21. The modulus of elas- ticity is taken as the ratio of the given unit stress to the corre- sponding total unit deformation. In Fig. 21 the variation with ultimate compressive strength is shown, and in Fig. 22, the effect of water content of the mixture. The plots are based on values of modulus of elasticity given in Tables 21 and 22 for stress of 650 Ib. per sq. in. In all tests the age of the concrete was over one year and the values of modulus of elasticity found are on the average higher than those generally taken to obtain for concrete at lower age. TESTS OF CONCRETE 79 c X M 'o 'i _ UJ s (0 450 65O 85O Unit Compress! ve Stress, Ib. per sq. in. Fig. 20. Modulus of elasticity of concrete at 450 to 850 Ib. per sq. in. ff ^^ O 00 . + 1- ^ o oX? x -1- #0 3 OO ^x< ^ <>0 o X o ^ >0 o * 4 K xV x X ++ / 3f O ^ o , > /' + + LEGE O Chicaqo + NewYt x RocKpo jd" Merame O .JolieT tX Clevela 94 Tests. Av ND Limestone rK Trap 1 Granite C R. Gravel 3ravei id Sandstone ocje 476 da^s So /o fa. t>. t, tt. + + OO 1000 I50O 2OOO 25OO 3OOO 35OO 4O Fig. Ultimate Compressive Strength, Ib. per sq. in. 21. _ Modulus of elasticity of 1:2:4 concrete at 650 Ib. per sq. in Variation with ultimate compressive strength. 80 AUXILIARY TESTS OF MATERIALS \5 Water in Mixture, Percent of Weight of Total Dry Materials Fig. 22. Effect of consistency on modulus of elasticity of concrete at 650 Ib. per sq. in. 8. TESTS OF LIME Chemical analyses and physical properties of quick lime and hydrated lime are given in Table 23. The analyses disclosed a high calcium lime. The quicklime passed standard specifications, but the hydrated product failed in point of CO 2 content, fineness, and soundness. The latter was used only as a minor component in the Portland cement plaster protections. 9. TESTS OF CALCINED GYPSUM Analyses and tests of Eastern and Western gypsum are given in Table 24 (p. 366). 10. TESTS OF MORTAR, PLASTER AND FILLING Results of compression tests on the mortar and plaster used in the coverings are given in Tables 25 to 27 (p. 367-370) and a further comparison of average and range of compressive strengths is given in Fig. 23. The specimens for these tests were taken of the mate- rials as mixed by the workmen. They were stored in air without artificial drying or curing. TESTS OF MORTAR, PLASTER AND FILLING 81 3500 L .0 3000 o500 w 2000 4) | 1500 a o 1000 "1 50O D O "1 ( Maximum j > "^^^^^_ Average 4 ^^ A . ! Minimum 3? twit - 1 1:4 Portland Cement-Gme Mortar - 32 tests X Av age 25 days _ >- tests- 13 Gygsum Mortar Avag507daysT 14 tests A X Av as?e 29 day s Ava^e503daysW Fig. 23. Average and range of compressive strength of mortar and plaster. The results of a series of mortar tests made by the Pittsburgh laboratory of the Bureau of Standards are given in Table 28 (p. 371). The same materials, proportions and average percentage of water were used as for the mortar and plaster of the column coverings. Table 29 (p. 369) gives results of compression tests on cylinders molded of the mixture with which gypsum block protections were filled. 11. TESTS OF HOLLOW CLAY TILE (a) Classification and Description The characteristics of the hollow tile employed as column covering are given in Table 30 (p. 372). The straight partition tiles, Nos. A to E, were non-porous, that is, burnt without sawdust or other filling. The curved tiles, Nos. F, G and H, in point of method of manufacture, were porous (b) Porosity and Absorption The porosity of the burnt clay (Table 31, p. 373-374) was obtained by drying samples of tile to constant weight at 112 C, and immersing in hot water under vacuum of 24 in. of mercury for about four hours, the porosity being based on the ratio of volume of water ab- sorbed to that of the test specimen. The weight of water absorbed is also expressed in Table 31 as a percentage of the dry weight. 82 AUXILIARY TESTS OF MATERIALS (c) Compressive and Transverse Strength Table 31 gives results of compression tests of all types of hol- low tile used in the column coverings. The curved tile was tested on end and the partition tile was tested both on end and on edge. By the latter method the load was sustained by the outer shells only and the average maximum unit loads developed are in all cases lower than for the tests made with the tile on end. The transverse tests (Table 32, p. 375) were made with center load and supports 10 in. apart. Failure generally occurred on inclined planes extending from points on the lower surface upward toward the loading line. In calculating the maximum outer fiber stress and horizontal shear, the moment of inertia and other properties of the section were obtained using the measured dimensions of each test specimen, (d) Temperature of Vitrification and Fusion In determining temperature of vitrification a number of pieces of each kind of tile were dried and weighed as for the porosity tests, and heated to 800 C. in a muffle furnace after which samples were withdrawn at temperature intervals of 30 C., allowed to cool slowly and tested for porosity. The temperature of vitrification was taken as the point or region of minimum porosity. In preparing samples for the fusion test, fragments of a num- ber of tiles from the same clay were broken up and a sample ob- tained by quartering. This was ground and again sampled, the final sample being ground to pass through an 80-mesh sieve and made into cones J/s in. high. These were fired in a small pot furnace between standard cones, the temperature of the furnace being de- termined with platinum thermocouples. Softening was indicated when the tip of the test cone went over. Fusion was taken as oc- curring at the stage when the tip of the cone reached the level of its base. The temperatures of vitrification and fusion determined for the hollow tile and brick are given in Table 33 (p. 376). 12. TESTS OF BRICK Results of tests giving the porosity, absorption, compressive and transverse strength of the brick used in the brick protections, are given in Tables 34 to 36 (p. 376-377). The brick was made in the Chicago district of calcareous sur- face clay and burnt to medium hardness, the color being gen- erally light red. The average dimensions in inches were 2^ by by 8. . TESTS OF GYPSUM BLOCK AND WALL BOARD 83 13. TESTS OF GYPSUM BLOCK Results of porosity, compression and transverse tests of gyp- sum block are given in Tables 37 to 39 (p. 378-379). The porosity tests were made on pieces of block dried for 24 hr. at 60 C. and saturated in kerosene under vacuum, the method being in other respects the same as given above for clay tile. In calculating modulus of rupture, the outside dimensions ot the block were used, the scoring and imprints being neglected. 14. TESTS OF GYPSUM WALL BOARD Results of transverse tests on gypsum wall board, in the dry condition and after saturation in water, are given in Table 40 (p. 379). The strength of the board was limited by the tensile strength of the paper facing, the latter developing greater resistance when the strain was parallel with the grain of the paper. 84 DESCRIPTION OF FURNACE EQUIPMENT v lndicotinq Potentiomerer ~ Rotary Switch Push Button Switch Fig. 24. Plan of testing room. VI. DESCRIPTION OF FURNACE AND RELATED EQUIPMENT The furnace and accessory equipment used in the tests were specially designed for the purpose and consist of a carriage and traveling crane for handling the test columns, a furnace in which the columns are subjected to fire, a ram with restraining frame for applying load, and hydrant with means for applying water in the fire and water tests. 1. BUILDING The tests were made at Underwriters' Laboratories, Chicago, 111., in a building designed for work of this character, a partial plan of which is given in Fig. 24 and a sectional elevation through the center in Fig. 25. The central portion of the building wherein the furnace for testing columns is located, is in one story about 37 feet high, an intermediate operating floor being located in the outer bays. Slid- ing skylights in the roof of the building above the furnace pro- vide means for ventilation. The operator's station on the upper floor is enclosed within fire resistive partitions with openings pro- tected by wired glass. 2. APPARATUS FOR HANDLING COLUMNS A carriage traveling on the lower flange of the I-beams placed above the storage bays for the columns is used for transferring the latter to the traveling crane. The column to be moved is lifted on threaded rods passing through the top plate of the column and plates supported on a truck contained within the carriage. This truck carries the column from the traveling crane to its loca- tion in the furnace on I-beams (a, Fig. 25) spanning the space above the furnace (Fig. 24). The column is finally attached to the head of the loading ram and lowered into position, 3. LOADING APPARATUS (a) Loading Ram The special hydro-pneumatic ram used for loading the columns was designed to maintain a constant load during the test and to develop characteristic deformation at the point of failure. The main ram is 36 in. in diameter and' is connected with a smaller lifting ram supported on its upper head. The operating medium is water maintained at the required pressure by an air compressor which discharges into steel pressure tanks connected with the ram cylinder through a 6-in. main. A pump is also provided to main- tain the water at any given level. 85 86 DESCRIPTION OF FURNACE EQUIPMENT Fig. 25. Elevation of testing machine. LOADING APPARATUS 87 Provision is also made for applying load by pumping water directly into the main cylinder. The gate valve in the main leading to the air pressure tanks is in this case closed and regulation of pressure obtained with a spring relief valve. (b) Controlling Devices A gate valve is placed in the pipe connection between the pressure tanks and the main cylinder, and also an automatic cut- off valve which shuts off the pressure tanks and releases the pres- sure in the main cylinder after a predetermined downward move- ment of the plunger of the ram has taken place. For the present tests the valve was set to begin shutting off pressure after the plunger had gone down 2 in., the valve releasing the pressure after an addi- tional 1%-in. downward movement. This caused maximum center deflection of the column at failure of about 15 in. As a further pre- caution a pressure of not less than 400 Ib. per sq. in. was main- tained in the lifting cylinder. The portion of the main cylinder chamber below the piston is connected with the outside air and also with a closed discharge chamber, with the latter through perforations in the cylinder lin- ing. A depth of water is maintained in this part of the cylinder to act as a cushion in case the travel of the ram piston, following a sudden column failure, should extend to the end of the cylinder. To obtain an approximate record of the load sustained by the column during test and during the period of failure, a steam engine indicator was mounted on the control board (S, Fig. 27) with its pressure chamber connected with the main cylinder of the ram and the drum actuated by a cord attached to the ram plunger. The resulting card diagram indicated on axes at right angles, the pres- sures in the main cylinder and the corresponding positions of the ram plunger. For convenience in operating, the valves for admitting and re- leasing pressure to all parts of the loading system are located at the control board (Fig. 27). Here are also located the load and pressure indicating gauges and the automatic and manually oper- ated controls for the starting switches of the air compressor and water pump. The main features of the installation are shown in Fig. 25, minor piping and details being omitted. (c) Restraining Frame The ram is supported from the upper transverse members of the frame, the lower set being embedded in the foundation pit. Each set consists of two pairs of 24-in. I-beams with cover plates. Two vertical tension bars on each side carry the reactions from the 88 DESCRIPTION OF FURNACE EQUIPMENT applied column loads. The lower end of the ram is supported laterally in an intermediate cross frame. (d) Bearing Details The ends of the test column are bolted to rolled steel plates 2 in. thick, which are in turn bolted to a cast steel foundation plate at the bottom and to the lower flanged head of the ram at the top. Between these and the column plates are placed adjustable bear- ings consisting of skew steel discs, the middle two of which can be turned to obtain even bearing. (e) Capacity and Calibration The machine has a load capacity of 545,000 Ib. and has been calibrated by the Bureau of Standards, using a comparison bar whose load-deformation relation was determined in the 2,300,000-lb. Emery testing machine at Washington. The accuracy of loading within the range used in this series of tests can generally be taken to be within one percent of the ap- plied load, with a possible extreme variation of two percent. The errors incurred are due to variation in the ram friction and in the indication of the test gauges used for determining the load. The latter were calibrated in a dead weight gauge tester before or after each test. 4. TESTING FURNACE (a) Combustion Chamber The chamber is 7 ft. square and 12 ft. high, exclusive of two shallow pits to receive falling material and carry off water during the fire stream tests. The sides are formed by two stationary brick walls, and two movable brick walls suspended in structural steel frames from overhead beams by trolleys (Fig. 25). These walls are pulled open by means of a motor-driven hoist. The top of the furnace consists of heavy fire clay blocks supported by steel I-beams and hangers. Some of the blocks are removable to permit installa- tion of the test column. Concrete made of Portland cement and crushed fire brick and reinforced with rods and wire mesh was later substituted for fire clay in making additional roof blocks. The bot- tom of the chamber is formed by the protection provided for the lower bearing plate and the supporting members of the restraining frame. The products of combustion are carried off through four flues extending from the furnace through the roof of the building. The furnace walls are provided with mica glazed observation holes, so arranged near the top, middle and bottom that all parts of the test column can be observed. TESTING FURNACE Fig. 26. General view of testing machine. 90 DESCRIPTION OF FURNACE EQUIPMENT bfl TESTING FURNACE 91 A general view of the furnace with a preliminary test column in place is given in Fig. 26. (b) Burners The furnace is heated by means of four primary blast burners extending in at the corners at the bottom of the chamber and all are arranged to discharge in an inclined direction upward and to- ward the adjacent corner. The burners are supplied with gas and air through tubes connecting with mains located in a shallow pit under the floor outside of the furnace. Gas is supplied to the fur- nace through a 6-in. pipe connected to the city service mains. Air is supplied by an electrically driven blower. The primary burners are operated with a smaller proportion of air to gas than is required for full combustion. The additional air needed to complete combustion and distribute the fire is sup- plied by secondary air inlets extending through the walls of the furnace at regular intervals toward the top, each inlet being pro- vided with a regulating valve (Fig. 25). The air from the burners is so directed as to avoid impingement on the test column and to set up a whirling motion of the furnace gases as an aid in securing uniform temperature distribution. (c) Operating Details Means for regulating the gas and air supplied to the burners and the draft from the furnace chamber are located on the main floor. An emergency cut-off valve with electrical control is placed in the gas main leading to the furnace, with switches for operating it set at several points in the building. A Hoskins direct reading millivolt-temperature indicator with connections to four chromel-alumel furnace thermocouples is placed near the furnace for use in regulating its temperature. 5. FIRE STREAM APPARATUS The pressure head for the hose stream used in the fire and water tests is supplied by air pressure in a tank of 4,500 gallons capacity. The water is applied through a standard Underwriter playpipe with nozzle l l /% in. in diameter (Fig. 28). It is connected with the hydrant through about twenty feet of 2^-in. cotton rub- ber-lined hose. A throttling valve is placed at the outlet to the hose and a pressure gauge connected with the base of the nozzle by means of which the desired pressure during water application is maintained. The water was applied to three sides of the column, the nozzle being moved back and forth on one side of the furnace and kept at a distance of about twenty feet from the center of the column (Fig. 24). 92 TEMPERATURE MEASUREMENTS Fig. 29. Temperature measuring instruments. VII. TEMPERATURE MEASUREMENTS All temperature measurements were made by the thermo- electric method, platinum-platinum, rhodium being used in the thermocouples placed in the furnace and base metal in those on the test columns. The electromotive force was measured with in- dicating and recording potentiometers and the corresponding tem- perature obtained from comparison calibrations with standard thermocouples whose temperature-emf. relations were known. The temperatures are expressed on the Centigrade scale. The Fahrenheit equivalents are given at the right of the time-tempera- ture plots. A Centigrade-Fahrenheit conversion table is given in Appendix -F (p. 389). 1. INSTRUMENTS A view of the instruments used is given in Fig. 29 wherein an indicating potentiometer or indicator is shown at A, a recording potentiometer at B, dial and push-button switches at C and D respectively, and busbar distributing board at E. (a) Indicating Potentiometer The potentiometer consists essentially of a means for securing a known variable electromotive force and balancing it against the electromotive force to be measured. ^) Standard Cell Battery "=p c Fig. 30. Wiring diagram of indicating potentiometer. A wiring diagram of a simple form of this instrument is shown in Fig. 30. Current from a battery flows through the resistance ABCDE, of which the portion BCD is a slide wire. A scale is at- tached to the slider giving the potential drop between points on 93 94 TEMPERATURE MEASUREMENTS f I bb INSTRUMENTS 95 the slide wire and the point B for a given value of the battery cur- rent. The latter is adjusted to the given value by opposing the electromotive force of a standard cell to the drop of potential over the resistance AB and varying the resistance R until the gal- vanometer included in the circuit shows no deflection. In a similar manner, an unknown electromotive force as that of a thermocouple, is balanced against the potential drop over some portion, BC, of the slide wire and its magnitude read from the attached scale. Corrections for variation in the temperature of the cold end of the thermocouple require in general the addition of a small electro- motive force to the observed one. With the potentiometer used in these tests, this could be accomplished mechanically at the time of making the observation by setting off the corresponding electro- motive force on the cold junction compensator, which has the same effect as moving the point B up the scale the same amount. The potentiometer indicator used in these tests is equipped with two scales, one reading from to 16 and the other from to 80 millivolts. The accuracy of this particular instrument was found to be within one-fourth of one per cent of the total range at all points on the scale. In the above method of measurement, the indication is inde- pendent of the resistance of the thermocouple and lead wires and no errors are introduced by variations in resistance caused by tem- perature changes in them. (b) Recording Potentiometer The wiring diagram of this- instrument is an exact equivalent of that of the indicating potentiometer (Fig. 30), the electromotive force of the thermocouple being automatically balanced and record- ed. It has scales of the same range as the indicating instrument and a 13-point selector switch provides connections for a maximum of 12 thermocouples. On the remaining switch point the battery current is automatically adjusted to the correct value. Records are made at intervals of one minute. Where the temperature dif- ferences between the different couples connected are not too large records can be made every half minute. (c) Accessories The accessories consist of a busbar board that was used for connecting any desired set of thermocouples with the recording potentiometer, a 12-point double-pole double-throw push-button switch by means of which the couples connected with the recorder could be read on the indicator, and a 24-point double-pole dial switch for connecting thermocouples directly with the indicator. TEMPERATURE MEASUREMENTS FURNACE TEMPERATURES 97 2. FURNACE TEMPERATURES Because of the high temperatures attained in column tests of long duration it was deemed advisable to use rare metal (Pt.-90 Pt. 10 Rh.) thermocouples for the measurement of furnace tem- peratures. (a) Location of Furnace Thermocouples In general four couples were used to measure furnace tem- peratures, placed two on each of two levels, at 3 ft. and 9 ft. above the fireproofing about the base of the column (Fig. 31). The couples on the 3-ft. level passed through the furnace walls near the northwest and southeast corners; those at the 9-ft. level, near the northeast and southwest corners. Laterally the junctions of the furnace pyrometers were placed 15 in. from the nearest point on the column. The above symmetrical distribu- tion is such that the center of gravity of the couple locations is identical with that of the portion of the furnace chamber above the fireproofing line on the column. The curves on the time-temperature plots (Appendix B) cor- responding to the respective furnace couples are designated as L-NW, L-SE, U-NE and U-SW, the letter preceding the dash indicating the level (L, lower; U, upper) on which the correspond- ing couple was placed ; those following it, the corner nearest to which the couple entered the furnace. The same system of designation is extended to include the few cases where couples were used in locations other than those mentioned. An exception is found in Test No. 20, in the case of curves L4 and U4. The corresponding couples measured fur- nace temperatures at points \y 2 in. from the column face, 3 ft. and 9 ft., respectively, above the fireproofing line. They were made of No. 16 iron and constantan wires with the junctions exposed directly to the furnace atmosphere. (b) Thermocouple Mountings Details of the thermocouple mounting are shown in Fig. 32. The use of rare metal couples necessitated porcelain protecting tubes whidh were covered with woven asbestos sleeving to prevent breakage from sudden temperature changes. The alundum tube with its winding of asbestos cord covered the outer two feet of the porcelain tube and served as a protecting sleeve where the. mounting passed through the furnace walls. The porcelain protecting tubes 1 differed somewhat in wall thickness, as furnished by three different makers. The maximum 98 TEMPER'ATURE MEASUREMENTS and the minimum wall thickness were & and ^ in., respective- ly. About 85 percent of the total number of tubes used had a wall thickness. of very nearly j in. Practically all of the woven asbestos sleeving was bought in two lots both of the same nominal size. The first lot, comprising approximately three-fourths of the sleeving used, ran about fifteen feet per pound, the second lot about twenty-four feet per pound, as unwound from the spool. (c) Connections to Instruments Permanent leads of No. 18 copper fixture wire were installed in a conduit leading from the case housing the recording poten- tiometer to the base of the furnace wall, from whence branches extended up to the thermocouple points. Hubbell receptacles were provided at the couple outlets (Fig. 31) which received the Hubbell plugs terminating the short leads attached to the cold ends of the furnace couples (Fig. 32). At the instruments the leads led to the busbar board where each of the four furnace couples was con- nected to three recorder points, and also through the push-button switch, with the indicator. The temperatures of the cold junctions in the heads of the furnace pyrometers were measured by thermocouples formed of one of the copper leads in each head and No. 18 constantan wires (Fig. 32) which were installed in the same conduit as the copper leads, all wires extending to the case housing the recorder, from whence copper wires led through the dial switch to the indicator. 3. COLUMN TEMPERATURES The base metal thermocouples used for measuring column temperatures were of No. 16 (B. & S. gauge) iron, No. 16 and No. 18 constantan, and No. 18 nickel wires, in the combinations, iron- constantan and nickel-constantan, 90 percent of the total number of couples used being of the iron-constantan combination. As sup- plied, a portion of the wire carried a thin waterproofed asbestos covering, while the remainder was bare. As used on the column, all wire was covered with closely fitting asbestos sleeving. (a) Attachment of Thermocouples to Column A preliminary test consisting in subjecting to heat in a gas- fired furnace two concrete covered lengths of wrought pipe, with thermocouples placed on the metal and in the covering, indicated that the proposed method of measuring column temperatures gave in general reliable results. Two methods of attaching the couples to the pipe section were tried out and appreciable differences of COLUMN TEMPERATURES 99 indication found to be caused by the given variation in this detail. By the one method, which will be termed "peening," the ends of the individual couple wires were placed in closely fitting holes drilled in the metal, and secured in place by driving in the metal around the holes, using a slotted punch placed in turn over each wire. Couples attached by the other method and referred to as "insulated," had fused or twisted junctions that were laid against a piece of mica about 0.01 inch thick placed between it and the metal. Since it was apparent that the peened couples gave more nearly the true temperature of the metal, the couples on the columns prepared subsequent to the preliminary test were attached by peen- ing, except that one or two insulated couples were added at cer- tain important locations as a check on the adjacent peened couples. The couples placed before the preliminary test was made were all insulated, and include those under the concrete covering or filling of all partly protected columns, Test Nos. 14 to 22 inclusive, and the couples of the concrete protected column of Test No. 28, and those on the vertical bars of the reinforced concrete column of Test No. 73. To decrease the danger of injury to the peened junctions in placing the coverings and in testing the columns, the region imme- diately surrounding the point of attachment was covered to a thickness of about l /& in. with asbestos wool loosely placed under a shield of sheet iron, 1 in. square and 0.015 in. thick. The couple wires, protected by the applied sleeving, were held firm- ly in place under a strap iron clip screwed to the column near the junction. The same clip also held' the shield over the asbestos wool in place. Similar clips, placed about eighteen inches apart, held the couple wires on the column up to one foot below the top bear- ing where they were led out through a 1%-m. pipe (Fig 31). The asbestos wool and shield were omitted over the insulated junctions since it was thought that they would not be subjected to as large strains as the junctions that were peened. As it was very difficult to attach couple junctions to the inside of hollow steel or cast iron columns by the peening method, the junctions were laid against the metal and protected with asbestos wool as described above. In placing couples in the column coverings or in locations other than on the metal, suitable means were used for supporting them in place, the methods varying with the conditions presented by the different types of columns and coverings. In all cases the details were so arranged as to reduce to a minimum heat inter- 100 TEMPERATURE MEASUREMENTS change between the couple junction and the couple wires. The latter was accomplished by placing a sufficient length of the wires immediately leading from the junction in a plane where, with the contemplated fire exposure, the same temperatures would normally obtain as at the junction. (b) Location of Column Thermocouples In all tests, except in those of timber columns, the thermo- couples were spaced vertically in four general locations, B, N, M and T, 1 ft. 6 in., 4 ft. 6 in., 7- ft. 6 in., and 10 ft. 6 in., respectively above the fireproofing line at the base of the column (Fig. 31). The lateral locations are numbered, 1, 2, 3, 4, etc., and marked by small solid circles on the sectional location diagrams of the time- temperature plots in Appendix B. The letter and the number designating, respectively, the vertical and horizontal position, as combined in the curve designations define completely the location of the couple. Additional couples, designated on 'the plots (Appendix B) as H2 and H3, were placed on some of the structural steel and cast iron columns at the base and on the edge of the beam bracket near the top (Fig 31). In general the letter i following the numbers in the column couple designations (Appendix B) is to be interpreted as insulated, referring to the method of attachment. Exceptions occur only in Test Nos. 3 and 4 (Fig. 90) in the case of the couples attached on the inside of the column. Letters indicating points of the compass are, in general, in- cluded in the designations of the couples that are not on the side of the column on which the general vertical distribution occurs. In the latter case, the couples are designated by the location letter and number only. Exceptions to the above are designations for the insulated couples in Test. No. 27 (Fig. 98), No. 47 (Fig. 101), and Nos. 62 and 63 (Fig. 126), which are located near the couple on the same level that has a direction letter in its designation. The couples whose curves on the plots for the timber column tests (Figs. 140 and 141) carry the designation T, were located 13 in. below the cap bearing, the lateral positions being evident from the location diagrams, as are also the location of the couples on the metal of the caps and pintles. The other vertical positions were the same as in the other tests. COLUMN TEMPERATURES / 10 1 . In Test Nos. 10 and 11 (Fig. 92) and No. 13 (Fig. 93) the prime mark (') on one couple designation in each test indicates that the given couple had no asbestos and sheet iron protection over it. In Test No. 21 (Fig. 96) the prime marks on two curves indi- cate couples whose leads for 19 in. immediately above the junction were protected by strips of asbestos board 1 in. wide and 34 m - thick, the object being to determine what influence possible heat interchange between the leads and the junction would have on the indication of the couple. (c) Connections to Instruments The wires of the column thermocouples led from the outlet in the column head above the furnace roof to the junction box placed to one side of the latter (Fig. 31), where they were put under bind- ing posts on a set of connecting blocks. Duplex leads of insulated iron and constantan wire were permanently installed from the junction box to the busbar board in the case housing the recording potentiometer from whence copper leads extended to the dial switch. The column couples could accordingly be connected with either the indicator or the recorder. 4. METHOD OF TAKING AND REDUCING OBSERVATIONS In most tests, the rate of temperature change was such that readings of both furnace and column thermocouples could be taken on the indicating potentiometer. Since it was found that the observations taken with it were more readily reduced to final form than the recorder records, the temperature determina- tions as given in the tables and plots are in general based on in- dicator readings, although the recorder was connected with the furnace couples in practically all tests, and its records served as a general check on temperatures during the test, and were also used in making occasional interpolations between indicator readings in plotting the results. 'In taking observations with the indicating potentiometer, the electromotive forces of the furnace or the column couples were read in succession in a chosen order, then repeated in reverse order, with equal time intervals (10 seconds or less) between consecutive read- ings. Mean values were taken of the direct and reverse readings on the respective couples, which, on the assumption of linear tem- perature change, are equivalent to simultaneous readings on all couples. The readings of the copper-constantan couples at the cold ;l$j ; TEMPERATURE MEASUREMENTS junctions of the furnace pyrometers, were reduced to the corre- sponding platinum-platinum rhodium electromotive forces, and added to the indications of their respective furnace couples. In the case of the iron-constantan column couples the cold junction correction, which was due to temperature differences 'between the junctions at the busbar board and the zero of the calibration plot, were set off directly on the compensator. For the nickel-constantan column couples a further correction was applied due to the electro- motive force introduced by the couple formed in connecting the nickel couple wire to the iron wire leading from the junction box above the 'furnace to the instruments. After the proper corrections to the observed electromotive forces had been applied, the corresponding temperatures were ob- tained from the calibration plots. 5. CALIBRATION OF THERMOCOUPLES (a) Furnace Thermocouples The furnace couples, in addition to being compared several times during the series of tests with a standard couple, were frequently submitted to a homogeneity test. The latter is in effect a determi- nation of the electromotive force, at frequent points along the couple wire, against standard wire of the same kind. This test was necessary since the electromotive force of a non-homogeneous couple, that is one whose thermoelectric properties vary from point to point along the wire, depends not only on the temperature of the junction, but also on the magnitude and position of the tem- perature gradients along the length of the couple, which in general were not the same as placed in the column testing furnace as in the furnace used for calibrations. Changes in calibration were found to be very small as long as the protecting tubes served their intended purpose of excluding the furnace gases. When a protecting tube was broken, or the couple wires had in any manner been exposed to the furnace gases, a homogeneity test was made. When such test showed no electro- motive force greater than the equivalent of 15C. at 1000 C., the couple was used again without further treatment. When this value was exceeded, the wire was either brought sufficiently near to its original (uncontaminated) condition by annealing, for several hours at 1500 C. by passing an electric current through it, or the bad portion of the wire was removed and good wire substituted. CALIBRATION OF THERMOCOUPLES 103 An accuracy within one percent of the indicated! temperatures was attained in the great majority tests. In the case of individual couples in a few tests the homogeneity determination indicated possibility of errors as high as 5 per cent, although the actual errors incurred were probably considerably smaller since the non-homo- geneous portion of the couple was not necessarily in the region of maximum temperature gradient. (b) Column Thermocouples Practically all of the wire used in constructing the column couples was bought in two lots, one of which was purchased in 1914, the other in 1917. A preliminary study of the variations in the thermoelectric properties among a number of samples taken from the wire in the first lot, indicated that to secure the desired accuracy,, calibration of individual couples made from this wire would be necessary, and that differences between the indications of individual couples were ap- proximately proportional to the temperature. The latter result showed that a good estimate could be made of the calibration of a given couple by comparing it at one tem- perature with a standard, and this practice was in general followed for all the couples made from the wire in the lot first purchased. Tests on about fifty representative couples made from the wire in the second lot showed sufficiently small variations among the in- dividual couples to permit the use of one temperature-electro- motive force curve for all the couples made from this lot. The results of the large number of tests made in studying the wire used in constructing column couples indicate that the accu- racy was within 2 percent of the indicated temperatures. 104 DEFORMATION MEASUREMENTS VIII. DEFORMATION MEASUREMENTS 1. GENERAL OUTLINE Included under this head are means for measuring (1) the unit compression and expansion over a definite gauge length, (2) the total depression or expansion of the column measured at a point above its heated portion, (3) the lateral center deflection. The general method used for measuring unit deformation and center deflection is shown in diagram in Fig. 33, and a view of the furnace with attachments in place is given in Fig. 34. Fine nickel- chromium alloy wires were connected to opposite sides of the test column at points symmetrical with its center, using for each a short IKS. Weight (3.3 Ibs.) n ^ Lower Microscope f _^. Q ^ ^ jUpper Microscope ^ \V\\\j k\\\ No. 30 Nichro ne Wire| ,, a 9 ; f k '/ [ I - N0.84 ' Wire v ' i < "f - \ ^^^ ^ v_ North and South Deflection Scales 1 ' II 1 ?J." ~ / _ _Ifi 1 -IM (0 "o / /, ''/, <' ^ 11 Z i6 16 Of IT' ?-l" I7.-2* x tast and West Deflection Scale L V *3" ... 77'- a 2" Fig. 33. Diagram showing method used for measuring deformation. length of heavier wire and a threaded insert. The other ends of the wires were weighted and passed over small flanged wheels located in the end posts. The movement of the wires was measured at an inter- mediate station on each side of the furnace. (a) Attachment and Protection of Wires A detail of the insert used for attaching the wire to the column is given in Fig. 35 as are also details of the water-cooled insulating tube. The hole for the insert was prepared before the column was covered or placed in the furnace and a IJ^-in. pipe with collar was bolted around it to provide a clear space for the wire. The pipe .projected outside of the covering to afford support for the insulating tube. With the column in place in the furnace, the inser ( t with wire attached and held in a suitably formed tool, was threaded into the column flange and turned so that the wire was left supported on the upper ledge of the insert. 105 106 DEFORMATION MEASUREMENTS GENERAL OUTLINE 107 The insulating .tube was designed to protect the wires from the heat of the furnace as otherwise they would break under the tension to which they were subjected. The circulating water was contained in the annular space between the 2-in. and 3-in. wrought pipes, the outer pipe being further protected by fire clay tubing. A 5-in. wrought pipe with the annular space between it and the 3-in. pipe filled with finely crushed fire brick was substituted for the fire clay tubing in the later tests of the series. Outside of the furnace the wires were shielded by sheet metal tubes. 2. UNIT COMPRESSION AND EXPANSION (a) Micrometers and Mounting The vertical movement of the wires was measured by means of microscopes set in micrometer slides (Fig. 36). The latter were mounted one on each end of nickel-steel bars supported near the mid- dle. The supports were provided with pivots and slides to secure angular, vertical and horizontal adjustment of the bar as a whole. The micrometer heads are graduated to 0.005 mm. and can be read to the nearest 0.001 mm., the total range of the slide being 50 mm. (b) Method of Taking and Reducing Observations Readings were taken at the same time on both sides of the fur- nace, the lower micrometer, upper micrometer and again the lower micrometer being read in the given order on equal intervals. The compression or expansion in the gauge length was obtained by mul- tiplying the movement of the upper wire relative to the lower wire at point of observation, by the ratio the distance from the column to the wire support in the end post has to the distance from the. latter point to the microscope (Fig. 33). The unit deformation is the aver- age of the values of total deformation obtained as given above, divided by the distance between gauge points (94 cm.) 3. CENTER DEFLECTION The lower gauge point was located near the center of the heaied length of the column and the center lateral deflection was measured by means of polished nickel scales, readings being taken with ref- erence to points on the wires and their reflection in the scales. The east and west deflection scales were placed perpendicular to the wires, and the deflection of the column was obtained by multiplying the observed movement at the scale by the ratio of distances as given in Fig. 33 of the column and of the scale, respectively, from the wire supports in the end posts, taking the average of values obtained on he two sides. 108 DEFORMATION MEASUREMENTS Fig. 36. Apparatus for measuring deformation CENTER DEFLECTION 109 The north and south deflection scales were placed parallel with the wires, small flat discs being attached to the latter in front of the scales with reference to which readings were taken. The deflection in the north or south direction is the average of the movements observed at the two posts, assuming the expansion of the measuring wires on both sides of the column to be equal. 4. TOTAL DEPRESSION OR EXPANSION The total vertical depression or expansion of the column before failure, as indicated by the movement of the head of the loading ram was determined for the columns in the fire and water test series, the timber columns and a few subsequent tests of structural steel and cast iron columns. For this purpose a single No. 30 wire on one side of the furnace only was attached to the bearing below the head of the ram plunger, the details of attachment and measurement of its move- ment being the same as described in par. 2 of this section. 5. CALIBRATION AND ACCURACY Calibrations of the instruments and appliances used for measuring unit deformation, and study of the test results, indicate possible maxi- mum errors of 20 parts in 100,000 (0.0002), which correspond to errors in instrument readings of about 0.008 in. (0.2 mm.). These errors were caused mainly by the change in sag of the wires due to moisture in the insulating tubes and also by movement of the column as a whole in the time interval required by a set of micrometer readings. The errors due to irregularities in micrometer screws and slides and in parallelism of slides and of microscopes as mounted on the support- ing bar were relatively small. In determining the total expansion or depression of the column by measurement of the movement of the loading ram, a large error was incurred in applying the 'load due to deflection of supports. Dur* ing the subsequent fire exposure under constant load the supports appear to have remained fairly rigid, the maximum errors for this period being probably within 0.01 in. (0.25 mm.) for the steel and cast iron columns and 0.04 in. (1 mm.) for the timber columns. The center deflection in the East and West direction was de- termined with an accuracy of about 0.04 in. (1 mm.) and in the North and South direction, within about 0.08 in. (2 mm.). The principal source of error in the latter case was unequal expansion of the wires due to unequal temperatures within the insulating tubes. IX. METHOD OF TESTING The columns in the fire test series were subjected to a constant working load and fire exposure increasing according to a predeter- mined time-temperature relation until failure occurred or until they had withstood the test 8 hr. or more. In the fire and water tests the working load was maintained con- stant and the column exposed to fire for a predetermined period when water at given pressures was applied by means of a hose stream. TABLE 41. COMPUTED AND APPLIED WORKING LOADS v Computed Load Applied Load Nominal SECTION Formula Area, 1/r Percent Sq. In. Lb. per Total, Total, of Sq. In. Lb. Lb. Com- puted Load Rolled H 16000-70 1/r... 10.17 75.6 10710 108900 119500 109 7 Plate and Angle . . do 13 00 111.8 8170 106200 116000 109.2 Plate and Channel do 8.76 64 7 11470 100500 111000 110 5 Latticed Channel do 7 78 44.0 12920 100500 111000 110 5 Z-bar and Plate do 9.32 81.7 10280 95900 105000 109^5 I-beam and Channel . . do 10 12 72.1 10950 110800 122000 110 1 Latticed Angle do 8.44 40.7 13160 111000 122500 110'.4 Starred Angle do 13.27 108.5 8435 111900 124000 110.7 Round Cast Iron (Vertically Cast) .... 10000-60 1/r 14.45 63.2 6210 89700 98500 109.8 Round Cast Iron (Horizontally Cast) .... do 14.73 68.2 5910 87100 95500 109.6 Round Cast Iron (Concrete filled) do 14.73 68.2 5910 87100 95500 109.6 . 1/d Steel Pipe As (13500-140 1/d) Steel Steel (Concrete filled) . . -f Ac (1000-11 1/d). 6.93 10750 Concrete 19.6 Concrete 104900 114500 109.2 38.74 784 Reinforced Steel Pipe do Steel Steel (Starred angles em- 18.36 11060 bedded in the concrete Concrete 17.7 Concrete 234700 236000 100.6 filling) 40.07 805 Square Vertically Reinforced Concrete 450 (Ac-fl5As).... Concrete 140 Concrete 450 Steel 12.7 Steel 90000 101000 112.2 4.00 6750 Round Vertically Concrete Concrete Reinforced Concrete 450 (Ac+15As).... 127 11.7 450 97500 107500 110.3 Steel Steel 6.00 6750 Hooped Concrete Concrete Reinforced Concrete. . . . 650 (Ac+15As).... 129 650 Steel 11.7 Steel 117000 129000 110.3 3.38 9750 Timber "oo' 1 -^ 1 ' 129.4 13.4 833 107700 118500 110.0 1 Effective length, inches. As Area of vertical steel, sq. inches, r Least radius of gyration, inches. Ac Area of concrete, sa . inches, d Diameter or side, inches. 110 LOADING FORMULAS AND APPLIED LOADS 111 1. LOADING FORMULAS AND APPLIED LOADS (a) Working Loads The formulas used in calculating the working loads to be placed on the columns were among those in most general use at the time the method of procedure for these tests was determined. They are given in Table 41, where are also given the properties of the columns and the calculated and applied working loads. The applied loads, which include weights of the column head and bearing blocks, (2500 Ib.) exceed the calculated working loads by about 10 percent for most of the columns. The principal part of the excess was incurred in the first tests of the series which were made before -the calibration of the loading ram was completed. It was decided to maintain the same loads for the subsequent tests as repre- sentative of a moderate condition of overload. No allowance was made for the load carrying capacity of the covering or filling in any of the tests except in case of the pipe columns where the loads were calculated according to the loading formula in use by the manufacturer who supplied the columns. (b) Loading to Failure In case the column withstood the 8-hr, fire test it was imme- diately loaded to failure under. full fire exposure. In the fire and water test series, three protected structural steel, the two unprotected cast iron and the three reinforced concrete col- umns were loaded to failure after they had cooled. Four protected structural steel columns after subjection to fire and water applica- tion were loaded to a little over twice the applied working load and reserved for use in further tests. 2. FIRE EXPOSURE (a) Character of the Fire The fuel used was carburetted water-gas from the city service mains. It was admitted at the primary burners with insufficient air for immediate complete combustion, in order to avoid excessive tem- peratures at the bottom of the furnace and allow further combustion to take place at the secondary air inlets. The gas was generally burned with sufficient air to prevent deposit of soot on the test column or furnace walls. (b) Preliminary Panel Tests During the first half hour it is not in general possible to regulate the temperature of a large testing furnace to correspond closely with predetermined temperatures, also, the determination of temperature is complicated by the lag of the furnace pyrometers with the rapid tem- 112 METHOD OF TESTING O ^ 11 FIRE EXPOSURE 113 perature rise occurring during this period. To obtain information on the effect of varying the rate of temperature rise, two panels built up of the five kinds of hollow clay tile used as protection in the column tests, were subjected to fire on one side for one-half hour and allowed to cool in place. The average furnace temperatures obtaining in the two tests are given in Fig. 37, and in Fig. 38 the condition of the panels after test is shown. Most of the tile developed fine cracks which extended to the inside of the inner shell and in a few cases through the cross webs to the outer shell. Cracks along the cross webs near the inner shells were common and some inner shells were loose. While in one test the indicated furnace temperature rise in the first ten minutes was over twice as rapid as in the other, the condition of the two panels after test was nearly the same. 900 800 700 600 500 400 300 ZOO 100 . 1700 1600 1500 1400 -1300 1800 -1100 -1000 -900 -800 700 600 500 400 300 aoo 100 ^^> ^*-* <--"~"*" ^ .,. *"*"' " J 7. AVERAGE COLUMN \ CURVE/d TESTS^ \/f PANEL NO ^^^ " / / / / 1 1 PANEL NO.I ^_ / / / I J / \ S 4* Furnace F*NEL 1 X4* Claq 1 Coyoles: t] 40. 1 ile Panel o.l4 base netal wire %1 i expo 4 ed;# in. in; PANEL X4' Clau. n pipe moo . NO. e Tile Pane rtincj. j Furnace ( enclose covered v Couples : No J;7Bia po ^Ith asbes 4 platinu ceiam tube OS insulati n wire mounting )n in.thick- D 5 10 5 80 25 30 Time in Minutes O) & Fig. 37. Furnace temperatures, preliminary panel tests.. 114 METHOD OF TESTING TEMPERATURE IN DEGREES FAHRENHEIT 000000000000000000 oooooooooooooooooo ^_(ON(OU)^OCM^OO)eor-->io*ocM-oo>a>r-io*ON- n r^ T ^h -T t 1 r~ T~ T 1 ! I I 1 L | t | s I \ I 1 I i [ 2 ^ \ c I j 1 L s f t I ^ J 4 * ^ S 5 r \ UJ ^ \ ? I ^ 8 } < 2 u z L ;? \ u f ^> ' l fc Q r^ I o: 2 7 \ o ,N \ | u i tb 1 1 1 t 1 s \ ^ I ti t- C u -=; < y ^~ P s ^ s y ^ !fe u ^ < s < -=^ e -? 5 o ' i ^ H > a i S S \, ft: I 4 \ t ^ I \ Q i 1 3 4 \ . L ^ V S \ ' -=r i t -=: t * \ / i ? r~ ! ? i s =: ? - ! ^ ? X s= ! ^=^ 5 2 ! ! = ! > <> > "~^ ? < ? < -<^ --^ ? ^~ . -.Tra f =3S > c a Ss 1 1 Z '" " s ui Q 2 S P -2 ^ -^T i g f bfl TEMPERATURE IN DEGREES CENTIGRADE FIRE EXPOSURE 119 substituting the given value of A in equation (1), the rate of rise, dG -= , being obtained from tangents drawn to the average curve at points K minute to one minute apart. As given by the differ- ence between the original and corrected curves, the lag decreases from a little over 100C. at 5 min. to 14C. at 20 min. From there on the decrease is gradual up to the uniform slope after 2 hr. (Fig. 39) where the lag correction is about 1C. For the furnace temperatures of the individual tests the corrections would be much more irregular than those on the average curve on account of irregularities of slope, although in general after the first hour, they would be relatively small and within the limit of error applicable to furnace temperature measurements. The furnace temperatures as given on the plots in Figs. 90 to 145 are indicated temperatures, as it was not deemed practicable to apply corrections for either lag or radiation effects to results of individual tests. (2) Radiation Effects In a gas-fired furnace where the source of heat is combustion within the chamber the inside of the walls of the latter will be at lower temperature than the furnace contents. The indications of a pyrometer introduced into the chamber to measure the temperature of its contents will be influenced by radiant inter- change of heat with the inclosure, the extent of the effect being de- pendent mainly upon the size of 1 the pyrometer and the temperature difference between the inclosure and the gaseous contents. To obtain a measure of the extent to which the indications of the furnace pyrom- eters were thus affected, an unprotected thermocouple of fine platinum platinum rhodium wires 0.004-in. (1/10 mm.) in diameter was sup- ported l*/2 in. outside of the closed end of a porcelain tube on similar wires of larger diameter that were passed through and sealed into the end of the tube, through which they led to the outside of the furnace. Two pyrometers of the same design as those used in the column tests (Fig. 32) were placed about three inches away from the unprotected couple and several runs made in a furnace having walls of the same material and of about the same thickness as those of the column furnace. Readings of the unprotected and the protected couples were taken at intervals of ^2 minute or less. The indicated temperatures obtained in a run extending to 8 hr. are plotted in Fig. 41. Those given by the unprotected couple were consider- ably higher than those of the protected couples because the tempera- ture of the fine wire was influenced to a much smaller extent by radiant heat interchange with the inside of the furnace inclosure than 120 METHOD OF TESTING that of the protected couples, and the temperatures indicated by it approximate those of the furnace contents as closely as can be attained without excessive refinements. The difference in indication due to radiation, as given by the lower curve in Fig. 41, was obtained by correcting the average indication of the protected couples for lag and subtracting the corrected value from that of the unprotected couple. While the variations in the resulting difference of indication are partly due to local and general variations in furnace conditions and minor changes in calibration of the unprotected couple, the general de- crease from about 150C. during the first half -hour to less than 50 C. at the end of 8 hr. can be ascribed mainly to decrease in temperature difference between the furnace contents and the inside surface of the furnace chamber. The average difference due to radiation was applied to the re- sults plotted in Fig. 40 (b) and the estimated indication of the un- protected fine wire couple is given by the upper curve. Since the indication of all pyrometers is influenced by lag and radiation effects, the comparison of furnace exposures afforded by the indicated temperatures given in Fig. 39, is limited by differences in these particulars incident with the types of pyrometers used. 3. FIRE AND WATER TEST PROCEDURE The duration of the fire periods varied from 22J4 min. to 1 hr., and that of the subsequent water application, from 1 to 5 min. The length of the maximum fire period was determined by the time within which water is generally applied in building fires, which was estimated as being one hour. The unprotected columns and some of the protected columns were given fire periods of shorter duration which were well within the time to failure of the corresponding columns in the fire test series. The duration and pressure of the water application were also varied for the different types of protection, the heavier ones being subjected to the most severe test conditions. In applying the hose stream, the nozzle was moved back and forth on one side of the furnace and maintained at a constant dist- ance from the column, the water being applied in succession over the full height on three of its sides. OBSERVATIONS DURING TEST 121 4. OBSERVATIONS DURING TEST Readings for temperature of furnace and of test column were taken at intervals of 2 to 15 min., the frequency of the readings depending on the rate of temperature change. Readings for de- formation were also taken at intervals of 2 to 15 min. Notes were taken on the character of the fire and on its effects on the test column at all stages of the test where the latter could be observed. 5. OBSERVATIONS AFTER FAILURE . ' , After the column had cooled notes were taken of its general condition and the covering was partly or wholly removed to de- termine the extent to which it was damaged. Measurements were taken of the amount and direction of the final buckle. 6. PHOTOGRAPHIC RECORDS Photographs were taken of all columns after test and also of a number of typical columns before test. The views were generally taken diagonally and from opposite sides so as to show all faces of the column, only one view 'being, as a rule, included in this report. X. RESULTS OF FIRE TESTS 1. FIRE TEST RESULTS IN TABLES AND FIGURES The results of the fire tests in points of time to failure, load sustained and relative fire exposure are given in Tables 42a to 42i. The columns are grouped by classes of protection and the thickness and material applied in each test are indicated. In Table 43 (p. 136) are given the period of expansion, the time to failure and the maximum temperatures attained in the metal. The period of expansion of a column when loaded and exposed to fire, is the period from the beginning of the test to the time when expansion of the column ceases, due to yielding of the heated metal under the applied load. The time to failure in the fire test extends from the beginning of the test to the time when the column is unable to sustain the applied working load. The time to failure of all columns in the fire test series is given in diagram form in Fig. 42 (p. 129) and the period of expansion of the steel, cast iron and concrete columns is given in similar manner in Fig. 45 (p. 134). 2. PHOTOGRAPHIC RECORDS Views before and after test of the columns in the fire test series are given in Figs. 58 to 82, Appendix A (p. 231-255). Since a large portion of the effects shown on the photographs of columns after test is due to the deformation and deflection taking place at failure, they should not be considered as representing the condition of the column or its covering immediately before this point was reached. The general condition of the test columns near the end of the fire period is indicated in their respective test logs. 3. FURNACE TEMPERATURES The temperatures of the furnace in the fire tests, as indicated by thermocouples located on two levels at symmetrical points with- in the chamber, are given by the upper curves in Figs. 90 to 141, Appendix B (p. 265-316). (a) Variations from Average Curve To obtain a measure of the variation in furnace exposure be- tween the different tests, the area under the average furnace curve given in Fig. 39, was calculated up to the end of successive in- tervals and compared with the area under the average furnace curve for each test up to a point near failure. The comparisons are given in Tables 42a to 42i as percentages of the area under the average curve of all tests. 122 FIRE TEST RESULTS IN TABLES AND FIGURES 123 TABLE 42a. RESULTS OF FIRE TESTS Unprotected Columns Test No. SECTION Nominal Area, Sq. In. 1/r Load Sustained During Teot Time to Failure, Hr-Min. Furnace Expo- sure, Percent Total Load, Lb. Unit Load, Lb. per Sq.In. 1 2 3 4 6 6 7 8 9 10 10A 11 12 13 Rolled H 10.17 13.00 8.76 7.78 9 32 10.12 8.44 13.27 14.73 14.73 14.45 14.73 Steel 6.93 Concrete 38.74 Steel 18.36 Concrete 40.07 75.6 111.8 64.7 44.0 81.7 72.1 40.7 108.5 68.2 68.2 63.2 68.2 63.9 68.2 119500 116000 111000 111000 105000 122000 122500 124000 95500 95500 98500 95500 114500 236000 11750 8900 12650 14250 11250 12050 14500 9350 6500 6500 6800 0-11M 0-19& 014 011 0-14& 017 14 021^ 0-34^ 34H 0-34M 0-45M 036 1-11% 95.6 97.0 101.4 101.1 100.0 89.6 96.3 99.0 101.2 101.7 100.3 103.1 101.9 99.3 Plate and Angle Plate and Channel Latticed Channel Z-bar and Plate I-beam and Channel Latticed Angle Starred Angle Round Cast Iron Round Cast Iron Round Cast Iron Round Cast Iron (Concrete filled) Steel Pipe (Concrete filled) Reinforced Steel Pipe (Starred angles imbedded in concrete filling) . o 4it^ : & i?e e n tS Fs S i e f l prope?tfes o S f the sections and details of protections are given in Tables (p. 37-52). to 124 RESULTS OF FIRE TESTS TABLE 42b. RESULTS OF FIRE TESTS Columns partly protected by concrete 'Protection Age of Cover- Load Sustained Time to Furnace Test No. SECTION Mixture Kind of Concrete ing, Days During Test, Lb. Failure, Hr. Min. Exposure, Percent 14 Rolled H 1-2-4 405 119500 1 0414" OK 1 15 Rolled H 1:2:4 Rockport granite 407 119500 0-48M 91.5 16 Plate and Angle. . . 1:2:4 New York trap 416 116000 0-44K 94.8 17 18 Plate and Angle. . . Latticed Channel. . 1:1H:4H 1:2:4 Hard coal cinders New York trap 408 418 116000 111000 0-41% 2 53 99.6 98 1 19 Z-bar and Plate. . . 1:3:5 Chicago limestone 414 105000 1-07M 95.8 20 I-beam and Channel 1-3-5 415 122000 1 24V6 100 2 21 I-beam and Channel 1-3:5 New York trap 416 122000 1 21^ 99 6 ', 22 Latticed Angle 1:2:4 Chicago limestone 408 119500 5 14 99.2 'R/i-entrant portions and interior filled with concrete. TABLE 42c. RESULTS OF FIRE TESTS Columns protected by plaster on metal lath Test No. SECTION Protection Age of Cover- ing, Days Load Sustained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure Percent 23 Plate and Angle... Two 2-coat layers of Portland cement plaster on expanded 508 1 17500 2 52 103.1 metal lath, each layer 1 in. thick, with a M-in. air space between layers 24 Plate and Channel. Two 2-coat layers of Portland 496 111000 2 24 101.6 cement plaster on woven wire lath, each layer % in. thick with a %-in. air space between layers 25 Z-bar and Plate. . . One 2-coat layer of Portland ce- 484 105000 1 -07^ 103.7 ment plaster, 1 in. thick, on expanded metal lath 26 Latticed Angle One 2-coat layer of Portland ce- 497 122500 1 _ 2ZYz 104.2 ment plaster, 1^ in. thick, on expanded metal lath 27 Round Cast Iron. . . One 2-coat layer of Portland ce- 498 95500 2 58 68.2 ment plaster, 1J^ in. thick or high ribbed expanded metal lath with a J^-in. broken air space 'Heavier load used as plate has 1/32 in. greater thickness than nominal. FIRE TEST RESULTS IN TABLES AND FIGURES 125 TABLE 42d. RESULTS OF FIRE TESTS Columns protected by concrete Test No. SECTION Protection Age of Cover- ing, Days Load Sustained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure, Percent Thick- ness, In. Mix- ture Kind of Concrete 28 Rolled H . 2 1:2:4 Chicago 437 119500 vtas 96.9 limestone u oo/^ 28A Rolled H 2 1:2:4 Chicago 438 119500 7 nois 95.2 limestone I vy% 29 Rolled H 2 1:2:4 New York 435 119500 4 QOL^ 99.5 trap * ooT'j 30 Rolled H 2 1:2:4 Joliet 439 119500 716 99.2 gravel 31 Rolled H 2 1:2:4 Cleveland 500 119500 4 11H 99.4 sandstone 32 Rolled H 2 1:2:5 Hard coal 503 119500 3 44 101.3 cinders 32A Z-bar and Plate 2 1:2:5 Hard coal 497 105000 4 02 100.5 cinders 33 Rolled H 4 1:2:4 Chicago 450 119500 8 08 99.2 limestone 1431000 33A Rolled H 4 1:2:4 Chicago 455 119500 8 07M 98.8 . limestone J405000 34 Rolled H ... 4 1:2:4 Rockport 452 119500 7 58 98.6 granite 34A Rolled H 4 1:2:4 Rockport 454 119500 7 23 102.5 granite 35 Rolled H 4 1:3:5 Chicago 504 119500 8 07 101.3 limestone J348000 36 Plate and Angle. . . 2 1:2:4 New York 445 116000 3-53M 100.3 trap 37 Plate and Angle... 4 1:2:4 New York 503 116000 7-34H 99.9 round trap 38 Plate and Channel. 2 1:2:4 Joliet 449 116500 5-28M 100.2 gravel 39 Plate and Channel. 4 1:2:4 Meramec R. 436 116500 3 41M 98.3 gravel 40 Latticed Channel.. 2 1:2:4 New York 501 111000 7 57 99.1 round trap 41 Z-bar and Plate. . . 4 1:3:5 Chicago 451 105000 8-24M 99.6 limestone 1332000 42 Z-bar and Plate. . . 4 1:3:5 Chicago 453 105000 8-11M 98.5 limestone 1333000 43 I-beam and 2 1:2:4 Cleveland 456 122000 4 11 98.7 Channel sandstone 44 I-beam and 2 1:3:5 Cleveland 458 122000 3-04M 100.6 Channel sandstone 45 Starred Angle 2 round 1:2:4 Meramec R. gravel 447 124000 1 47 99.7 46 Latticed Angle. . . . t2 1:2:4 New York 451 122500 6-43K 99.0 47 Round Cast Iron... 2 1:2:5 trap Hard coal 446 95500 2 482i 99.6 cinders m Heavier load used as plates have 1/32 in. greater thickness than nominal. f2-in. outside rivets, 3p-in. outside angles. jLoad necessary to cause failure of column. After 8 hr. the load was increased until failure occurred. 126 RESULTS OF FIRE TESTS TABLE 42e. RESULTS OF FIRE TESTS Columns protected by Hollow Clay Tile Protection Age of Load Test No. SECTION Thick- ness of Tile, In Kind of Tile, Filling, and Method of Tying Cover- ing, Days Sustained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure Percent 48 Rolled H 2 New Jersey semi-fire clay 496 119500 1 50 100.9 No filling Outside wire ties 49 Rolled H 4 Same as No. 48 497 119500 1 40 99.9 50 Plate and Angle. . . 2 Surface clay, Boston. . . Granite concrete fill 494 116000 1 -05% 99.8 50A Plate and Angle . . . 2 Same as No. 50 505 *1 17500 1 _ 591^ 101.8 51 Plate and Angle . 4 Same as No. 50 487 116000 2 17% 101.8 51A Plate and Angle . . . 4 Same as No. 50 507 116000 2 _ 551^ 100.5 52 Plate and Channel. 2 Ohio shale 513 111000 1 40% 100.2 Cinder concrete fill Outside wire ties 53 Plate and Channel. 4 Same as No. 52 495 111000 1 -22% 103.0 54 Latticed Channel.. 2 Ohio semi-fire clay .... 489 111000 3-17% 101.1 Trap concrete fill Outside wire ties 55 Z-bar and Plate... 2 Ohio semi-fire clay .... 485 105000 3 46% 99.5 Limestone concrete fill Outside wire ties 56 Z-bar and Plate... 4 Ohio semi-fire clay .... 491 105000 3-33^ 100.3 Limestone concrete fill Wire mesh in joints 57 I-beam and Surface clay, Chicago. . 491 122000 3 23 100.0 Channel . ... 4 Limestone concrete fill Outside wire ties 58 I-beam and Surface clay, Chicago. . 502 122000 4-35% 101.7 Channel Two 2 Hollow tile fill Wire mesh in joints 59 I-beam and Surface clay, Chicago. . 490 122000 1-33% 101.2 Channel Two 2 Hollow tile fill Outside wire ties 60 Latticed Angle 2 Ohio semi-fire clay .... 487 122500 3 09^ 100.4 Trap concrete fill, placed before tile was e/vf S6t Outside wire ties 61 Latticed Angle 2 Ohio semi-fire clay 501 122500 0-50% 100.3 No filling Outside wire ties 62 Round Cast Iron... 2 Porous semi-fire clay, round New Jersey 483 95500 4 UK 101.3 No filling Outside wire ties 63 Round Cast Iron. . . 2 Same as No. 62 493 95500 2- 57y 2 100.6 round 76 Rolled H 2 Ohio shale ; Ohio semi- fire clay; semi-fire clay, New Jersey . . 42 119500 4-25K 98.1 Limestone concrete fill Wire mesh in joints Tile covered with %-in. layer of gypsum plas- ter 77 Plate and Angle. . . 4 Semi-fire clay, N. J.; surface clay, Chicago; surface clay, Boston. . 45 116000 4-42% 97.3 Limestone concrete fill Wire mesh in joints Tile covered with 5^-in. layer of lime plaster ""Heavier load used as plate has 1/32 in. greater thickness than nominal. FIRE TEST RESULTS IN TABLES AND FIGURES 127 TALE 421. RESULTS OF FIRE TESTS Columns protected by gypsum block Test No. SECTION Thickness of Block, In. Protection Age of Cover- ing, Days Ixmd Sustained During Test. Lb. Time to Failure, Hr.-^Iin. Furnace Exposure, Percent Kind of Block, Filling and Method of Tying 64 Rolled H.. 4 Western gypsum (solid) 502 119500 4-43M 104.5 Hollow gypsum block fill Wall ties in joints 65 Plate and 2 Western gypsum (solid) 505 111000 2-21M 104.5 Channel Solid gypsum block fill Wall ties in joints 66 Latticed 2 Eastern gypsum (solid) 495 111000 2 36 101.0 Channel Poured gypsum fill Wire mesh in joints 67 Rolled H.. 4 Same as No. 66 492 119500 5-31^ 101.2 67A Rolled H.. 4 Same as No. 66 491 119500 6-24M 99.7 TABLE 42g. RESULTS OF FIRE TESTS Columns protected by brick Test No. SECTION Thickness of Brick, In. Kind of Brick and Filling Age of Cover- ing, Days Load Sustained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure, Percent 68 Rolled H.. 2K Chicago common brick set 498 119500 1-40M 104.0 on edge and end Brick fill 69 Rolled H.. m Chicago commonbrick laid 502 119500 7-13M 101.2 flat Brick fill 128 RESULTS OF FIRE TESTS TABLE 42h. RESULTS OF FIRE TESTS Reinforced Concrete Columns Effective length, 12 ft., 8 in. Concrete Ixmd Test No. SECTION Outside Dimensions and Reinforcement Age, Days Sus- tained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure, Percent Mix- ture Kind 70 Square Vertically Reinforced 16-in. square Four 1-in. sq. bars 1:2:4 Chicago limestone 433 101000 J294000 8-40M 101.1 71 Square Vertically Same as No. 70 1:2:4 New York 450 101000 7 22% 99.2 Reinforced trap 72 Round Vertically 17 in. diameter 1:2:4 Chicago 520 107500 8 04H 102.1 Reinforced Six 1-in. sq. bars limestone J250000 73 Round Vertically Same as No. 72 1:2:4 New York 442 107500 7 57^ 98.5 Reinforced trap 74 Hooped Reinforced 17 in. diameter. . . . 1:2:4 Chicago 522 129000 8 06J-3 99.5 Six%-in. sq. bars limestone 1243000 M-in. (j) spiral on IMi-in pitch] 75 Hooped Reinforced Same as No. 74 1:2:4 New York 460 129000 8 01M 100.7 trap U63000 JLoad necessary to cause failure of column. After 8 hr. the load was increased until failure occurred. TABLE 42L RESULTS OF FIRE TESTS Timber Columns Nominal net section, 11^ by 11^ in. Effective length, 12 ft., 8^ in. Test No. Species Bearing Details Protection of Column and Cap Load Sustained During Test, Lb. Time to Failure, Hr. Min. Furnace Exposure, Percent 78 79 Longleaf pine... Cast iron cap and pintle One 2-coat layer of Portland cement plaster 1 in. thick on woven wire lath, M-i Q - air space. Age, 30 days 118500 118500 2 - 15M 50 97.6 105.2 80 81 Longleaf pine... and pintle Steel plate cap and timber strut Steel plate cap One thickness of z A-\n. gypsum wall board with metal corner beads nailed to column Unprotected 118500 118500 1 13 35 103.5 113.0 82 and timber strut Unprotected 118500 45M 106.6 83 and pintle 118500 38^ 106.1 and timber strut NOTE: Details of design of reinforced concrete and timber columns are riven in Figs. 8 to 10 (p. 30-33) and further details of protections are given in Fables 3i to 3j (p. 53-54). FIRE TEST RESULTS IN TABLES AND FIGURES 129 TIME TO FAILURE IN FIRE TESTS GROUP 'NO' 1 2545678 Unprotected Structural Steel Unprotected Cd3t Iron Unprotected nmDer ynprot ectsd rip* Columns ffcrtly Protected JStrvictura Steel Haater Protections Two inch Hollow Glau, Tile and DricK Protections Four Inch Hollow Claq Tile and BrlcK Protections Twoln.5ol!dSypsuin BlocKProtetcWis four In.Solid Gypfum Btoch Protect ions Two Inch Concrete Protections Four kien Concrete Protect loirs Reinforced Concrete Coivunoa *> i 8 II li 18 ) Hi HHI HI Hi HHI HI HI HHI HHI HHI HHI HI HH Hi I | mm \ mm mmm M~mm mm ay mmm E= Mi m mmmm er 8 hours, lofld on column was ed until (bilure occurred at loOd noted i| HH MHl 6O 78 at. | ^^^H M i vl 76 II 5"IA HBHHI m mmmt mmmmm tmmmm ._ 65 66 64- 67 32 I! mmmm - 30 i 70 72 74- IH^E^M ^i mmmm mmmm ==: mmmmmnm mmmmmmm mmmm ammm MP mmmm* mmmm ammmi mil ill ii mm i vn mmmi fmmmml rnmax mmmm mmaa mmrnnm LU 3 333000 j 348000 ! c \ f . f HOUF I. - ?s i : r 1 i esoooo 3 frWOOO Fig. 42. TViwe ^o failure of columns in fire test series. 130 RESULTS OF FIRE TESTS 4. COLUMN TEMPERATURES The temperatures attained in the test columns and their cover- ings are given by the lower curves in Figs. 90 to 141, Appendix B The arrows on the plots indicate the time of failure for each test hollow ClavTile Protect Thermocouple Locations Fig. 43. Temperature variation over cross section of typical columns. COLUMN TEMPERATURES 131 (a) Temperature Variation Over Length of Column The highest temperature generally obtained over the middle half of the column, the loss of heat at the ends due to conduction tending to maintain a lower temperature in the adjacent portions of the column. The difference was seldom very large and in some tests, due to local variations in furnace temperature or in column protection, the highest temperature was indicated by one of the end couples. (b) Temperature Variation Over Cross Section The temperature variation laterally across the section was quite marked in all protected column tests, the highest temperature in the metal obtaining almost invariably at the outer edges. In Fig. 43 this variation is given for some typical columns near failure. The temperature indicated by the couple in the covering, varied with its distance from the surface and the character of the cover- ing material. (c) Dehydration Points In the tests with concrete or gypsum protections and rein- forced concrete columns, temperatures in the column of about 100 C. (212 F.) obtained over a considerable length of time due to evaporation of water in the concrete and gypsum. To less ex- tent, this effect was present in tests with plaster on metal lath and concrete filled hollow clay tile protections. 5. LONGITUDINAL DEFORMATION AND AVERAGE TEMPERATURE The unit longitudinal deformation measured over a 37-in. gauge length located immediately above the mid-height of the column (Fig. 33) together with the computed average effective tempera- ture over the same length, are plotted for a number of fire tests in Figs. 146 to 171, Appendix C (p. 322-347). (a) Computation of Average Effective Temperature The relative location of gauge points and thermocouple points and the temperature variation between the latter assumed in calcu- lating the average effective temperature in the gauge length, are shown in Fig. 44 for the case of the Rolled H section. It can be readily shown with reference to the diagram at (a) that the average 132 RESULTS OF FIRE TESTS M Fig. 44. Assumed temperature variation between thermocouple points. temperature in the gauge length of the edge couples, N, M, and T, located in the (3) position, is given by, .115 T + .143 N + .742 M. = Av. (3) where T, N and M are the temperatures indicated by the respective thermocouples at a given time. Similarly with reference to the diagram at (b) it can be shown that the average temperature in cross section at a given level, say at the M position, is expressed by, .17 (1) + .38 (2) + .45 (3) = Av. M. (1), (2), and (3) being the temperatures indicated by thermocouples in the respective positions in the cross section. The average effect- ive temperature in the gauge length (Av. G. L.) can then be ob- tained from the relation. /Av. 3 \ Av. G. L. = Av. M. V M 3 / For the other structural steel sections the average temperature at the M or N level was obtained by taking the sum of parts of temperature readings of couples in the (1), (2) and (3) positions as given below, the derivation being similar to that foj the Rolled H section : Plate and Angle, .33 (1) + .38 (2) + .29 (3). Plate and Channel, .20 (1) + .27 (2) + .53 (3). Latticed Channel, .27 (1) + .365 (2) + .365 (3). Z-bar and Plate, .441 (1) + .232 (2) + .327 (3). I-beam and Channel, .223 (1) + .294 (2) + .483 (3). Latticed Angle, Test No. 26, .484 (1) + .35 (2) 4- .166 (3). Latticed Angle, Test No. 60, .513 (2) + .487 (3). Starred Angle, .416 (1) + .584 (2). LONGITUDINAL DEFORMATION AND AVERAGE TEMPERATURE 133 The average temperature in the vertical plane was obtained from the same expression as that given for the Rolled H section in all cases except that for the Plate and Channel section, due to a slight difference in the relative positions of couples and gauge points, the average temperature was given by, .122 T + .742 M + .136 N. In the case of the cast iron and pipe columns, the average temperatures plotted pertain to the outer surface of the metal. Readings obtained on the inside of a number of the unfilled cast iron columns indicate temperatures generally lower by 5 to 10 C. For the reinforced concrete columns, Figs. 169 to 171, the tempera- tures plotted are those of the vertical reinforcing bars. The maximum error involved in computing average tempera- tures by the above method is estimated to be within 20 C. for tests where the covering material remained in place until near the time of failure. Where parts of the covering fell off, as for tests plotted in Figs. 163; 165 and 166, the resulting local heating and irregular temperature distribution introduced much larger errors as evidenced by the discrepancy between the computed tempera- ture and the corresponding unit deformation. For such tests the limit of error is probably as high as 50 C. (b) Deformation Under Heat and Load On application of working load to the column before starting the fire test, a compressive deformation resulted, which in a few tests increased slightly during the first part of the fire period caused either by shrinkage stresses set up by dehydration of the covering or by increased load on the metal portion of the column resulting from cracking of the covering. As the temperature increased, the steel, cast iron and reinforced concrete columns expanded up to a point where the yielding due to the load became equal to or greater than the thermal expansion. (See curves, p. 321-347.) The unit expansion per degree C. during this period varied generally between 0.000010 and 0.000014 for the steel and cast iron columns, the average of the calculated values for each of these two types of columns being very nearly 0.0000125. These were taken from room temperature up to a point where the rate of expansion began to decrease rapidly due to yielding of the metal. The total observed unit expansion up to the point where expansion ceased, varied in the tests of steel columns, from 0.0044 to 0.0066, the average being 0.0054. For the cast iron columns the variation was from 0.0060 to 0,0071, with an average of 0.0064. The lower values are due mainly to local heating which caused the metal to yield 134 RESULTS OF FIRE TESTS PERIOD OF EXPANSION GROUP BE 3 4 5 6 7 8 Unprotected Structural Steel Unprotected Cast Iron Unprotected Pipe Columno Parti q Protected Structural Steel Plaster Protections Two inch Hollow ClaqTile .and Brick Protections Four Inch Hollow Ciou,nie and BricK Protections TvvOin.3olidGqpsuni BlocH Protections ourlnSolkiGupsun 4. ,A !? : m tmm mm Mmmm MM fmmmm. m^mmm mmmtm ummm mmm* wmmm tm mm mm mmmmm Mi mmmm MM mmmmm ^HHI ^H S2 M i t mmmm mmtmm ammm mmmm Ml = mm, % MWM I i ^ fc>b W BlocK Protections Two Inch Concrete Protections Tour Inch Concrete Protections Reinforced Concrete Columns 6>A \\ 3EA mmmm MVi = = m ! i c 1 HOI 4 JRS 3 t D / 8 Fig. 45. Expansion period of steel, cast iron, and concrete columns in fire test series. LONGITUDINAL DEFORMATION AND AVERAGE TEMPERATURE 135 over a relatively short portion of the gauge length before full expan- sion had been attained elsewhere. The columns under the lower unit loads generally attained higher expansion than those more heavily loaded. In the tests of reinforced concrete columns unit expansions of 0.0000095 to 0.0000102 per degree C. obtained with values of maxi- mum unit expansions of 0.0023 to 0.0046. The point of maximum expansion was less sharply defined than for the steel and cast iron columns and the expansion attained was lower. The compressive deformation taking place subsequent to maxi- mum expansion varied in rate and duration with the type of column and the load carrying capacity of the covering material. In some tests the total compression before failure more than equalled the previous expansion. In the tests of timber columns slight expansions were noted during the first few minutes of the fire period, subsequent to which the movement was one of progressive depression, the principal de- formation occurring at the bearings on the steel or cast iron cap introduced near the top of the column. (c) Period of Expansion The period of expansion and time to failure of all columns in the fire test series are given in Table 43 (p. 136-137). A comparison is given between the length of the portions of the test period preced- ing and following the point of maximum expansion, as also the maximum temperatures obtaining at the latter point and at failure. The period of expansion of the steel, cast iron and concrete columns is shown in chart form in Fig. 45. (d) Maximum Column Temperatures These are given in Table 43 for the point of maximum expan- sion and the time of failure, the temperatures being obtained from the time-temperature curves extended where necessary to the fail- ure point of the given test. The edge temperature for the structural steel columns is the maximum temperature indicated by the couple located nearest to the edge of the section on any of the four regular thermocouple levels. For the cast iron columns the temperatures given pertain to the outer surface of the metal and for the reinforced concrete columns, to the vertical reinforcing bars. The edge temperatures given for the timber columns were measured on the metal cap at the edge of the column bearing. The maximum average temperatures for the sections of the columns having the highest edge temperatures were computed by 136 RESULTS OF FIRE TESTS TABLE 43. TIME TO FAILURE, PERIOD OF EXPANSION AND MAXIMUM COLUMN TEMPERATURES Test No. Period of Expansion Hi. Min Time to Failure. Hr. Min Difference, Percent of Expansion Period Maximum Observed Temperature in Metal, Dee. C. At End of Expansion Period At Failure Couple Level Edge Average Couple Level Edge Average 1 08 11% 40.6 B 530 B 624 2 017 19', 13.2 N 633 N 668 3 11 14 27.3 M 557 M 626 4 09 11 22.2 M 510 M 578 5 11 14% 29.5 M 620 M 670 6 13 17 30.8 B 623 B 660 7 11 014 27.3 M 547 M 622 g 19 21J^ 13.1 B 575 B 620 9 24 34% 42.7 M 584 5| M 694 s 10 23 34^ 50.0 B 638 B 745 10A 11 22 27 34% 45% 55.7 67.6 N B 626 570 [Measured j on surface N B 718 758 [Measured [on surface 12 14 36 157.0 N 502 of column of column 13 52 1 11% 37.9 M 781 J ""M" "'872' J 14 45 1 04% 42.8 M 623 M 810 15 40 48% 20.6 N 670 N 730 16 40 44J^ 11.2 M 671 M 717 17 40 41% 4.4 N 700 N 724 18 2 00 2 53 44.1 N 672 N 788 19 1 00 1 -07% 12.1 M 831 M 860 20 1 10 1 24^ 20.7 N 853 N 909 21 1 10 1 21% 16.8 M 820 M 858 22 1 40 5- 14 214.0 M 504 N 790 23 2 30 2 52 14.7 M 573 '"556"' M 650 '"635"' 24 2 00 2 24 20.0 N 504 498 N 614 609 25 57 1 - 07% 18.9 N 564 522 N 653 610 26 1 10 1 -23^ 19.3 N 512 501 N 606 598 27 211 2 58 35.9 T 607 N 735 28 3 30 6-33% 87.5 M 590 545 N 750 '"716"' 28A 3 31 7 09% 103.5 N 515 484 N 723 690 29 3 15 4-38^ 42.8 N 565 525 N 735 693 30 3 45 716 93.8 N 570 535 31 2 46 4 \\y 2 51.5 N 533 504 "N"' "732" '"702"' 32 2 32 3 44 47.4 N 547 503 B 722 685 32A 2 50 4 02 42.4 M 576 486 N 736 656 33 7 50 *8 08 B 546 533 B *554 *541 33A 7 50 *8 - 07% M 536 522 M *547 *532 34 6 34 7 58 2L3'" N 598 574 N 718 690 34A 5 50 7 23 26.6 N 571 542 N 732 700 35 7 - 40 *8 07 N 539 527 - N *558 *546 36 3 10 3 53% 22 ; s --- B 603 571 B 695 664 37 6 10 7 34M 22.8 B 545 525 B 664 644 38 3 10 5 28% 73.0 N 531 516 N 696 683 39 3 20 3 41% 10.6 M 759 M 794 40 5 01 7 - 57 58.5 B 574 '"536"' M 881 837 41 7 30 *8 24% N 527 496 N *561 *535 42 8 00 *8 - 11M B 553 526 B *560 *535 43 2 50 4 11 "'47.'6'" N 601 553 N 769 724 44 2 23 3 04M 28.8 N 562 520 N 727 677 45 1 41 1 47 5.9 B 519 510 B 575 570 46 4 55 6 43H 36.8 N 543 N 695 47 2 03 2 48% 37.2 N 568 N 710 48 1 32 1 -50 19.6 M 542 '"537"" M 647 '"636" 49 1 21 1 40 23.4 M 561 M 654 50 55 1 05% 19.5 N 682 N 775 50A 1 44 1 59H 14.9 B 695 B 778 51 51A 2 11 2 40 2-17% 2 55H 4.8 9.7 N N 617 600 "'546'" 549 N N 670 678 ""m" 622 52 1 32 1 40% 9.5 N 520 497 N 593 570 53 1 17 1 22% 6.8 N 580 535 N 659 603 54 2 20 3 - 17% 40.9 B 543 493 B 820 764 55 2 51 3 46% 32.6 M 684 527 M 889 692 56 2 30 3 33H 42.3 M 643 564 M 795 732 57 2 15 3 23 50.4 N 749 593 T 894 755 58 59 4 00 1 25 4 35% 1 33% 14.9 10.3 T 624 523 T 714 591 60 1 47 3 09H 77.0 "N"' "561" '"532"' "N"' "750" "'737'" 61 45 50% 11.7 N 585 571 N 638 625 62 3 00 4 11*4 39.7 M 584 M 760 63 2 20 2-57^ 26.8 N 598 N 730 'Column loaded to failure after 8 hr. fire exposure. LONGITUDINAL DEFORMATION AND AVERAGE TEMPERATURE TABLE 43.-TTME TO FAILURE, PERIOD OP EXPANSION AND MAXIMUM COLUMN TEMPERATURES Concluded 137 Test No. Period of Expansion, Hr. Min. Time to Failure, Hr. Min. Difference, Percent of Expansion Period Maximum Observed Temperature in Metal, Deg. C. At End of Expansion Period At Failure Couple Level Edge Average Couple Level Edge Average 76 77 64 65 66 67 67A 68 69 70 71 72 73 74 75 78 79 80 81 82 83 3 45 4 10 4 32 2 20 2 32 5 01 5 45 1 10 5 30 5 00 2 40 5 00 4 10 5 50 4 50 4 - 25y 2 4 42% 4-43% 2-21^ 2 36 5 31^ 6 2iy 2 1 40% 7-13% *8 40% 7-22% *8 04^ 7 57H *8 - 06^ *8 01% 2 15% 50 1 13 35 45% 38^ 18.0 12.9 . 4.1 1.1 2.6 10.1 11.4 43.9 31.3 'ite.'e'"'. N N T N T - N '"N"' N N T T N B B 553 600 513 479 463 496 '"606" 550 642 468 475 528 493 552 524 558 N B T N T " M'" N N N B T N N B ' H H H H H H 663 690 868 490 491 '"980" 754 706 *797 942 *623 845 *589 *788 360 510 564 432 510 544 619 652 '"516 553 Measured on vertical reinforcing bars 677 716 Measured Ion vertical [reinforcing I bars 91.0 *Column loaded to failure after 8 hr. fire exposure. H. temperature measured on metal cap at edge of timber column bearing. the method given in par. 5a above, the limits of error involved being somewhat higher than for the plotted results, as each determina- tion is based on fewer couple readings. In the case of the unpro- tected and partly protected columns, gypsum block protections and a few of the concrete and hollow clay tile protections, the average temperatures are not given, since the rapid temperature rise and ir- regular distribution obtaining near the end of these tests made the computed results unreliable. At the point of maximum expansion, the average over the sec- tions having the maximum temperature, ranges for tests of struc- tural steel from 484 to 593 C. (903 to 1099 F.) with an average of 530 C. (986 P.). Similarly at the time of failure in the fire tests the computed values vary for the given structural steel columns from 570 to 837 C. (1058 to 1601 F.), the average being 668 C. (1234 F.). The high temperatures obtaining at failure in a number of the tests indicate that at this point the covering carried a large proportion of the applied load. The same effect appears to have in- fluenced to much smaller extent the temperatures attained at the point of maximum expansion. The temperatures on the surface of the metal at failure and at maximum expansion in the tests of cast iron columns were on the average about 70 C. (126 F.) higher than the average over the section for structural steel columns at the given stages of the test. 138 RESULTS OF FIRE TESTS Total Expansion in Inches TOTAL VERTICAL DEFORMATION 139 6. TOTAL VERTICAL DEFORMATION (a) Before Failure Measurement of the movement of the head of the loading ram was made for a number of columns as described in Sec. VIII., par. 4, and the results are plotted in Figs. 46 and 47. An approximate measure of the total expansion and depression was also obtained from the card of the indicator (Sec. VI., par. 3b) mounted on the control board. The total expansion of the steel columns varied from % in. to J /s in. and of the cast iron columns from 1 in. to J^ in., the lower values being due to local heating caused by impairment of the covering over a short length, which induced failure while other portions of the .column were at much lower temperature. The expansion of the reinforced concrete columns was about one-half that of the cast iron columns. The depression of the top of the timber columns is given in Fig. 47. These deformations were due mainly to crushing of the wood at the metal cap, the heat conducted by it into the bearing causing a large reduction in the compressive strength of the wood in contact with it. (b) At Failure With the setting used for the cut-off valve of the cyl : rder, the .esulting downward movement at failure varied between 2j^ and 3*4 in. As given on the indicator card, from J4 m - to 2j^ in. of this travel was made under nearly full pressure. The indicated pressure in the cylinder at the end of the travel varied from one-fourth to one-half of the original pressure in tests with steel columns and some of the cast iron columns. In the case of the cast iron columns that broke before the end of the travel and of the reinforced con- crete columns that failed under working load, the pressure indi- cated immediately before the valve cut off was less than one-fourth of the original pressure. 7. LATERAL DEFLECTION (a) Before Failure The center deflections observed, where large enough to have any bearing on the manner of failure of the column, are noted in the respective test logs. In most tests, decided deflection did not begin until after the point of maximum expansion was passed. The deflection observed at the last reading before failure, varied for different tests from less than y% in. to 2% in. In almost all cases the direction of the deflection before failure was the same as that 140 RESULTS OF FIRE TESTS c o w w g Q. 4 in. long tested 14 days after the fire test developed ultimate compressive strength % of 730 Ib. per sq. in. (Figs. 62 and 96.) Test No. 20. I-beam and Channel. .1:3:5 trap concrete 34 min. trace of color on steel flanges. 36 min. color in concrete. 40 min. flanges dull red. 60 min. concrete and exposed steel bright red. 1 hr., 8 min. no cracks or spalling of concrete. 1 hr., 10 min. maximum expansion. 1 hr., 24, x /^ min. failure, buckling to south, maximum at 6 ft. above base. After failure. Concrete remained in place except where crushed at middle, top and bottom. Rivet heads probably helped to hold it. (Figs. 62 and 96.) Test No. 21. I-beam and Channel. 1:3:5 trap concrete 38 min. traces of color on steel flanges. 1 hr., 10 min. maximum ex- pansion. 1 hr., 20 min. no cracks or spalling of concrete. Steel flanges dark red, concrete bright red. 1 hr., 21 24 min. failure, buckling to north, maximum at 6 ft. above base. After failure. Concrete remained in place except where crushed at failure. (Figs. 62 and 96.) Test No. 22. Latticed Angle. 1:2:4 limestone concrete 25 min. concrete glowing on corners; a number of fine cracks noted on all faces. 1 hr., 40 min. maximum expansion. 3 hr. surface of column glowing at white heat. 4 hr., 50 min. large vertical cracks appeared under brackets near top. Very little cracking or spalling of concrete before fail- ure. 5 hr., 14 min. failure with local buckling of steel and crushing of concrete about 11 ft. above the base. Unprotected brackets probably caused failure, at this point by conducting heat into angles. After failure. Except at point of failure concrete did not appear greatly damaged. Limestone calcined to depth of 1 in., and one month after test the whole exterior concrete had become loose due to air slaking of the lime. From temperature of steel at 3 hr., it is probable that the concrete carried most of the load after that time. (Figs. 62 and 95.) LOG OF FIRE TESTS 145 (c) Plaster on Metal Lath Protections Test No. 23. Plate and Angle. Two 1-in. layers of Portland cement plaster on expanded metal lath 12^2 min. distinct thud heard caused by failure of covering due to ex- pansion; plaster cracked and spalled on all faces at top of column near bottom of 'bracket. 23 min. to 1 hr., 15 min. some six or eight fine vertical and horizontal cracks, 3 in. to 8 in. long appeared on east, south and west sides from 1 to 8 ft. above base. Very little change up to failure except that all cracks opened up slightly. 2 hr., 30 min. maximum expansion. 2 hr., 41 min. deflection of % in. northwest, increasing to 1 in. west at 2 hr., 51 min. 2 hr., 52 mm. failure, buckling to west, maximum at 7j^ ft above base. After failure. Plaster of outer layer dehydrated and both outer and inner layers very crumbly. Both layers fairly well keyed to lath. (Figs 63, 97 and 148.) Test No. 24. Plate and Channel. Two 7/s-in. layers of Portland Cement plaster on woven wire lath 8*4 min. distinct thud heard; plaster cracked and spalled on all faces at bottom of bracket exposing lath on corners. 14 min. to 1 hr., 45 min. some fifteen fine vertical cracks, 3 in. to 8 in. long, appeared on all sides near corners. 2 hr. maximum expansion. 2 hr., 15 min. very little change except some cracks opened up to l /& in. 2 hr., 24 min. failure, with local buckling about 6 ft. above base. After failure. Outer layer of plaster dehydrated; inner layer fairly hard except at failure point. Plaster well keyed to lath. (Figs. 63, 97 and 148.) Test No. 25. Z-bar and Plate. One 1-in. layer of Portland cement plaster on expanded metal lath 10 min. slight noise heard; plaster cracked and spalled on all sides under bracket. 48 to 54 min. fine vertical cracks noted on all faces near corners, opening up slightly towards end of test. 57 min. maximum ex- pansion. 41 min. slight deflection to north noted, increasing to J A in at 1 hr., 1 min. 1 hr., 7^4 min. failure, buckling to north, maximum at S% ft. above base. After failure. Plaster appeared to be in fairly good condition and was quite hard except where crushed. Plaster well keyed, covering inner face of lath. (Figs. 63, 98 and 149.) Test No. 26. Latticed Angle. One iy 8 -in. layer of Portland cement plaster on expanded metal lath 10 min. to 17 min. cracking and some spalling of plaster^ on bracket. 20 min. to 1 hr. some fifteen fine vertical cracks, 6 in. to 12 in. long, ap- peared near corners on all sides; also horizontal cracks near bottom. Be- fore failure bracket cracks had opened up to */> in. and others nearly H i n 1 hr. 10 min. maximum expansion. 1 hf. 2Z l / 2 min. failure with local buckling- about 6 ft. above base. After failure. Very little strength in plaster, very crumbly. Keys cov- ered lath on inside. -)4 in. air space between plaster and angles. (Figs. 63, 98 and 149.) Test No. 27. Round Cast Iron. One 1^-in. layer of Portland cement plaster on high-ribbed metal lath 18 min. vertical-and horizontal cracks under bracket. 1 hr., 40^ min. to 2 hr., 5 min. several fine vertical and horizontal cracks, 3 in. to 12 in. long, mostly near middle. 2 hr., 11 min. maximum expansion. 2 hr., 50 min. cracks opening up to % in. 2 hr., 30 min. slight deflection to southwest noted, increasing to H in- at 2 hr., 51 min., and 1 1 A in. southwest at 2 hr.j 56 min. 2 hr., 58 min. failure, buckling to southwest and breaking about 6 ft. above base. After failure. Plaster fairly hard where not crushed. Plaster pushed through to iron except at ribs; average thickness of plaster 1H in. (Figs. 63, 98 and 149.) 146 RESULTS OF FIRE TESTS (d) Concrete Protections Test No. 28. Rolled H. 2-in. 1:2:4 limestone concrete 30 min. to 45_4nin. a few fine vertical cracks at middle and top of east face opening up slightly towards failure. No spalling before failure. 3 hr., 3C min. maximum expansion. 6 hr., 33% min. failure, buckling to west, maximum at 6 l / 2 ft. above base. After failure. Concrete fairly hard although calcined on surface. Flanges exposed at middle, and flange edges exposed at several points, this all occurring at failure. Wire tie not broken. (Figs. 64 and 99.) Test No. 28A. Rolled H. 2-in. 1:2:4 limestone concrete. Not tied 2 hr., 55 min. to 3 hr., 23 min. several fine vertical cracks 3 in. to 12 in. long, and about 3 in. from corners, appeared on east and west faces. No spalling or other effects noted before failure. 3 hr., 31 min. maximum expansion. 5 hr. sHght deflection to west noted, increasing to Y$ in. at 6 hr., 2 min., and \y 2 in. west at 7 hr., 2 min. 7 hr., 9% min. failure, buckling to west, maximum 6% ft- above base. After failure. Concrete surface fairly firm although discoloration and calcination extend to depth of 1 in. Concrete fell off at failure exposing about one half of area of steel flanges. (Figs. 64, 100 and 150.) Test No. 29. Rolled H. 2-in. 1:2:4: trap concrete 50 min. to 3 hr., 50 min. several fine vertical and horizontal cracks ap- peared on east and west faces which became larger near failure. No spall- ing or other effects noted before failure. 3 hr., 15 min. maximum expan- sion. 3 hr., 30 min. slight deflection to west noted, increasing to y$ in. at 4 hr., 2 min., and \y> in. west at 4 hr., 32 min. 4 hr., 38^4 min. failure, buckling to west, maximum at SjA ft. above base. After failure. Surface of concrete reddish in color. No fusion noted. Concrete fell off at failure exposing flange for 1^ ft. on south side and flange edges at other points. Wire tie not broken. (Figs. 64, 101 and 151.) Test No. 30. Rolled H. 2-in. 1:2:4 Joliet gravel concrete . 37 min. fine cracks noted in brackets. 3 hr., 4 min. to 5 hr., 5 min. a number of fine cracks, 2 in. to 12 in. long, mostly vertical and near edges, appeared on east and west faces opening up to & in. near end of test in some cases. No spalling before failure. 3 hr., 45 min. maximum expan- sion. 6 hr., 40 min. slight deflection to east noted, increasing to $ in. at 7 hr., 9 min. 7 hr., 16 min. failure, buckling to east, maximum at 5^2 ft. above base. After failure. Concrete on surface fairly hard after test but disinte- grated in 30 days, due to air slaking. Flanges and flange edges exposed in places due to spalling of concrete at failure. (Figs. 64 and 102.) Test No. 31. Rolled H. 2-in. 1:2:4 sandstone concrete 28 min. to 1 hr., 5 min. vertical cracks appeared on east and west faces about 3 in. from edges running nearly full length of column, opening up in places to % in., also a few fine vertical cracks on north and south faces in lower half. 45 min. southeast corner spalled off 3 in. deep from 3 ft. to 6 ft. up, exposing edge of steel. 1 hr., 5 min. to 3 hr. vertical cracks at corners became continuous, opening up to & in.; concrete on southeast and southwest corners generally spalled off or loose in lower half exposing edges of flanges in places. Very little change to failure except for minor cracking and spalling. 2 hr., 46 min. maximum expansion. 2 hr. slight center deflection to northwest noted, increasing to fy& in. at 3 hr., 1 min., and 2% in. northwest at 4 hr., 11 min. 4 hr., 11^ min. failure, buckling to west, maximum at 5^ ft. above base. After failure. Concrete on flanges disintegrated and crumbly. Nearer the web the concrete was harder but had apparently lost much strength, (Figs. 64, 103 and 152.) LOG OF FIRE TESTS 147 Test No. 32. Rolled H. 2-in. 1:2:5 cinder concrete 3 hr. no cracking or spalling noted. 3 hr,, 20 min. to 3 hr., 38 min. a few small vertical cracks 4 in. to 6 in. long appeared near corners on east and west faces in lower half extending in length and opening up towards end of test. No spalling before failure. 2 hr., 32 min. maximum expan- sion. 3 hr. slight deflection to east noted, increasing to Y 2 in at 3 hr 31 min., and 1$4 in. east at 3 hr., 43 min. 3 hr., 44 min. failure, buckling to east about 6 ft. above base. After failure. Concrete very crumbly to a depth of about 1 in. Quite hard and apparently little affected at column web 5 in. from surface (Figs 65, 104 and 153.) Test No. 32A. Z-bar and Plate. 2-in. 1:2:5 cinder concrete 2 hr., 50 min. maximum expansion. 3 hr. no cracking or spalling noted. 3 hr., 50 min. fine vertical cracks developing on all faces mostly near northeast and southwest corners. 3 hr., 30 min. slight deflection to north noted, increasing to ^ in. at 3 hr., 51 min., and Ifcj in. north at 4 hr., 1 mm. 4 hr., 2 mm. failure, buckling to north, maximum at $y 2 ft. above base. After failure. Concrete crumbly and dehydrated to a depth of about \V 2 in. Beyond this it was harder and apparently little affected. (Figs. 65, 104 and 153.) Test No. 33. Rolled H. 4-in. 1:2:4 limestone concrete 2 hr. to 4 hr. fine vertical cracks 6 in. to 12 in. long on east and west faces, 4 in. from corners, in lower half; also small cracks in bracket. Cracks opening slightly towards end of test; no spalling. 7 hr., 50 min. maxi- mum expansion. 8 hr. column still supporting working load with no ap- parent change; less than ^ in. deflection! 8 hr., 2 min. load increased with fire going until failure occurred under load of 431,000 Ib. with local buckling about 10 ft. above base, at 8 hr., 8 min. After failure. Outer ^ in. of concrete soft and could be easily knocked off 8 days after test, and was dehydrated for another \ l / 2 in., inside of which it was hard and apparently little affected by the heat. (Figs. 65, 105 and 154.) Test No. 33A. Rolled H. 4-in. 1 :2 :4 limestone concrete. Not tied. 30 min. slight surface flaking at several points. 34 min. to 40 min. fine cracks noted on east and west sides of bracket. 2 hr., 10 min. to 5 hr., 20 min. three or four fine vertical cracks 3 in. to 24 in. long on east and west faces, 3 in. from corners, in lower half. No spalling or further crack- ing before failure. 7 hr., 50 min. maximum expansion. 8 hr. column still supporting load with no apparent change; less than ^ in. deflection. 8 hr., 5 min. load increased with fire going until failure occurred under load of 405,000 Ib. with buckling to the east, maximum 7 ft. above base, at 8 hr., 7% min. After failure. In lower 8 ft., concrete checked and pitted with small holes of 3z in. to t\ in. diameter, and hard to depth of over & in. Concrete calcined to depth of l}/2 in. from surface. Concrete on flanges broke loose at failure due in part to absence of wire tie. (Figs. 65 and 106.) Test No. 34. Rolled H. 4-in. 1:2:4 granite concrete 32 min. to 1 hr., 5 min. fine vertical cracks about 3 in. from corners mostly on east and south sides, 5 ft. to 9 ft. up; also cracks on all sides in bracket. 1 hr., 28 min. cracks opened generally & in. to 3s in. width. 2 hr., 13 min. crack through concrete at southeast corner 6 ft. up. 4 hr., 7 min. 54-in, crack through northeast corner 6 ft. up. 6 hr., 34 min. maxi- mum expansion. 6 hr., 40 min. very little change except for slight spalling on northwest corner 8 ft. up. 7 hr., 33 min.- spalling on northwest corner 6 in. by 3 in. by 3 in., at 8 ft. up; spalling on southeast corner, 6 in. by 6 in. by 20 in., &/ 2 ft. up, exposing steel. 3 hr. slight deflection to east noted, in- creasing to ^j in. at 7 hr., 31 min. 7 hr., 58 min. failure, buckling to east, maximum at 7 ft. above base. After failure. Incipient fusion of concrete \ l / 2 in. to 2 in. in depth throughout. Concrete underneath very soft and crumbly. (Figs. 65, 107 and 155.) 14$ RESULTS OF FIRE TESTS Test No. 34A. Rolled H. 4-in. 1:2:4 granite concrete 55 min. to 1 hr., 45 min. small vertical cracks appeared on all faces 3 in. to 5 in. from corners, mostly from 5 ft. to 7 ft. up, opening up to ^ in. in some cases; also several cracks in bracket. 3 hr., 16 min. cracks opening up to Y$ in., no spalling except small piece at bracket. 4 hr., 44 m i n> gas shut oft for \ l / 2 min. to cool furnace. 5 hr., 50 min. maximum expansion. 6 hr., 30 min. gas shut off for 2 min. to clear furnace; small spall noted on southwest corner 7 l / 2 ft. up. 7 hr. gas shut off for 2 min.; incipient fusion apparently present. Minor spalling of corners noted. 6 hr., 30 min. slight deflection to west noted, increasing to y 2 in. at 7 hr. 21 min. 7 hr., 23 min. failure, buckling to west, maximum at 5 ft. above base. After failure. Incipient fusion of concrete 1 in. to \y 2 in. in depth over whole surface. (Figs. 65 and 108.) Test No. 35. Rolled H. 4-in. 1:3:5 limestone concrete 56 min. fine vertical crack, 12 in. long, on both faces at southeast cor- ner at bottom, 4 in. from edge. 3 hr. no spalling or further cracking noted. 4 hr. to 7 hr. furnace filled with heavy flame; impossible to see column. 7 hr., 40 min. maximum expansion. 8 hr. column still supporting working load with no apparent change; deflection less than % in. Load increased with fire going until failure occurred under load of 348,000 Ib. with local buckling, 7 l / 2 ft above base, at 8 hr., 7 min. After failure. Surface concrete hard and sand fused throughout to depth of y in. to % in. Limestone completely calcined up to 1 in. from surface, and soft and dehydrated up to 2y 2 in. from surface. It was harder further in, although less so than in 33 and 33A. (Figs. 66, 109 and 156.) Test No. 36. Plate and Angle. 2-in. 1:2:4: trap concrete 37 min,. small crack on west face, 5 in. long, running up diagonally from southwest corner, 2y 2 ft. up. 1 hr., 13 min. small spall, 3 by y in. on southeast corner, 6]/ 2 ft. up. 1 hr., 20 min. to 3 hr., 40 min. several fine cracks at bracket. 3 hr., 10 min. maximum expansion. 3 hr., 46 min. several vertical cracks 2 in. from corners on east and west faces, 2 ft. to 4 ft. up. No spalling before failure. 3 hr. slight deflection to northwest noted, increasing to % in. at 3 hr., 44 min. 3 hr., 53J4 min. failure, buck- ling to west, maximum at 6 ft. above base. After failure. Concrete soft and crumbly to a depth of \y 2 in. to 2 in. (Figs. 66, 103 and 151.) Test No. 37. Plate and Angle. 4-in. 1:2:4 trap concrete, round section 35 min. to 1 hr. small cracks noted on all sides at bracket. 1 hr., 25 min. to 1 hr., 40 min. spalling of southwest and southeast corners at bracket. 4 hr., 20 min. no further cracking or spalling. 6 hr., 10 min. maximum expansion. 6 hr., 24 min. spalling across west face at bracket about 1 in. deep. 7 hr., 10 min. spalling on south face at bracket; impossible to observe lower part of column on account of furnace gases. 6 hr., 30 min. slight deflection to west noted, increasing to y 2 in. at 7 hr., and 1^4 m - west at 7 hr., 30 min. 7 hr., 34^ min. failure, buckling to west, maximum at 5*/2 ft. above base. After failure. -Considerable fusion and flowing of concrete to depth of 2 in. and incipient fusion for 1 in. to \ l / 2 in. further in, in lower 8 ft. Partial fusion to l / 2 in. depth above this point. Concrete crumbly for 1 in. inside fusion portion; fairly hard further in. Trap rock extends to surface quite generally in upper portion which was not fused. (Figs. 66, 110 and Test No. 38. Plate and Channel. 2-in. 1:2:4 Joliet gravel concrete 45 min. to 2 hr., 55 min. several fine vertical cracks appeared on east and west faces about 2y 2 in. from corners, 5 ft. to 8 ft- above base, some opening up to ik in., also several cracks in bracket. 3 hr., 10 min. maxi- mum expansion. 3 hr., 26 min. horizontal cracks on north face 4 ft. up, y$ in. wide. .4 hr., 6 min. vertical cracks on east and west faces opening up to J /s in.; very few cracks on north and south faces. 5 hr., 4 min. con- crete loose on corners 3 ft. up. 5 hr., 28 min. no spalling. 4 hr. slight deflection to east noted, increasing to l / 2 in. at 5 hr., 21 min. 5 hr., 28^4 . failure, buckling to east, maximum at 2J4 ft. above base. LOG OF FIRE TESTS 149 After failure. Concrete calcined to depth of 1/4 in. and very crumbly to depth of 2 in. Inside of this point on web side, concrete was quite hard and apparently little affected" by the heat. (Figs. 66, 111 and 158.) Test No. 39. Plate and Channel. 4-in. 1:2:4 Meramec River gravel concrete 19 min. to 26 min. vertical cracks developed on east and west faces near corners in lower half and at bracket. 26 min. 2 ft. spall on northwest corner near middle. 28 min. to 40 min. vertical cracks extending upward and opening up. 40 min. horizontal crack, 5 ft. up, across north face. 45 min. large spall on southwest corner, 7 ft. up. 1 hr., 20 min cracks open- ing up to y 2 in. in some cases. 1 hr., 26 min. concrete cracked through northeast corner, this corner spalling off from 4 ft. to 8 ft. up at 2 hr., 6 min., exposing edge of steel for 4 ft. 2 hr., 13 min. southwest corner spalled off for 3 ft. near middle exposing steel. 3 hr. northwest corner and west side spalled off above middle of column exposing steel on corner for 2 ft. 3 hr., 20 min. maximum expansion. 3 hr., 41 J4 min. failure with local buckling 6 l / 2 ft. to 8 ft above base. After failure. Concrete inside of spalled or cracked portions was quite hard and split witk fracture of aggregate. Aggregate also fractured by cracks produced in the fire test. (Figs. 66 and 112.) Test No. 40. Latticed Channel. 2-in. 1:2:4 trap concrete, round section 5 hr., 1 min. maximum expansion. 6 hr., 56 min. no cracking, spalling or fusion of concrete. 7 hr., 25 min. a number of vertical cracks on east and west sides in lower half varying from very fine to Y% in. by 16 in. at southeast 3 ft. up. No spalling or fusion. 7 hr., 55 min. cracks opening up; the crack noted above open % in.; no spalling, possibly some fusion. 7 hr., 57 min. failure with local buckling about 5 ft. above base. After failure. Fusion of concrete from depth of J^ in. to \Yz in. near failure point. Very little concrete had run. Concrete outside of steel gen- erally disintegrated; between channels it is harder. (Fig. 67, 113 and 159.) Test No. 41. Z-bar and Plate. 4-in. 1:3:5 limestone concrete. 10 min. fine vertical crack, 2 in. long, on west face near north corner 7 ft. up. 1 hr. to 1 hr., 50 min. several vertical cracks, 3 in. to 12 in. long, appeared on west face near corners .in middle section of column; some open- ing up to y% in.; no spalling. 2 hr., 50 min. concrete cracked through for 2 in. length on northwest corner, 5 ft. up. 7 hr., 30 min. maximum expan- sion. Lateral deflection at middle of column less than Y% in. 8 hr. column still supporting working load with little apparent change; no spalling. Load increased with fire going until failure occurred under load of 332,000 lb., buckling to south, maximum 6 ft. above base, at 8 hr., 24% min. After failure. Concrete reddish in color and dehydrated to depth of 1 in. from surface. Concrete outside of flanges dehydrated and crumbly. (Figs. 67, 114 and 160.) Test No. 42. Z-bar and Plate. 4-in. 1:3:5 limestone concrete 1 hr., 15 min. small crack on southwest corner at bracket. 2 hr., 20 min. fine vertical crack on west face 4 in. from northwest corner, 4 ft up. 8 hr. maximum expansion. Column still supporting working load with little apparent change; no spalling; deflection less than ^ in. Load in- creased with fire going until failure occurred under load of 330,000 lb. with buckling to north, maximum 6 ft. above base, at 8 hr., 11^2 min. After failure. Concrete affected same as in Test No. 41. (Figs. 67, 115 and 161.) , . Fb 'S'lEi Test No. 43. I-beam and Channel. 2-in. 1:2:4 sandstone concrete 13 min. vertical crack, 4 in. long, on southeast corner, S l / 2 ft. up, caus- ing slight spalling at 20 min. 21 min. to 30 min. vertical cracks appeared on east and west faces near corners, mostly in middle part of column. 30 min. southeast corner spalled off to a height of 5^ ft. exposing edge of steel and ties for 4 ft. 33 min. to 41 min. vertical cracks on east and west faces extended nearly full length of column. 45 min. southwest cornei spalled off 4 ft. to 10 ft. up. 51 min. southeast corner spalled off 6 ft. tc 9 ft. up. 55 min. cracks opening up to l /4 in. in places. 1 hr., 15 min. southwest corner spalled off, lower 4 ft. 2 hr., 50 min. maximum expan- ISO RESULTS OF FIRE TESTS sion. 3 hr., 5 min. concrete checking all over surface. 4 hr., 11 min. failure, buckling to north, maximum 6 ft. above base. After failure. Channel flanges and ties on south oxidized. Concrete discolored on surface and very crumbly for depth of 1 in., rest dehydrated and possessed little strength. Fractures split aggregate which also seems to have lost much of its strength, crumbling under light hammer blows. (Figs. 67, 116 and 152.) Test No. 44. I-beam and Channel. 2-in. 1:3:5 sandstone concrete 17 min. vertical crack on northeast corner, 2 ft to 5 ft. up, corner spalling off at 18 min., also vertical crack on northeast corner, 3 ft. to 7 ft. up, corner spalling off at 25 min. 22 min. vertical cracks on both sides of northwest and southwest corners. 32 min. southeast corner spalled off in lower 3 ft. 35 min. vertical cracks on all faces about 2 in. from corners running full length of column. Edges of steel exposed for lower 7 ft. on northeast and southeast corners; concrete loose on northwest and south- west corners. 36 l /2 min. southwest corner spalled from 6 ft. to 7 ft. up. 1 hr., 2 min. spall east side near middle for length of 3 ft. exposing flange edges. 1 hr., 23 min. all corners at bracket spalled or cracked. 1 hr., 24 min. northwest corner spalled from 6 ft. to 9 ft. up. l.hr., 35 min. south- east flange of channel dull red at middle of column; no other change. 2 hr., 23 min. maximum expansion. 3 hr., 4J4 min. failure, buckling to north, maximum 6 ft. above base. After failure. Concrete generally very soft and crumbly. Falls off column readily in large pieces. (Figs. 67 and 116.) Test No. 45. Starred Angle. 2-in. 1:2:4 Meramec River gravel concrete, round section 20 min. to 30 min. a number of deep cracks, mostly vertical, in lower half of column; concrete becoming loose in places. 35 min. some spalling near middle of column. 36 min. cracks in upper half of column; practi- cally all sides have large cracks. 38 min. crack on west, 3 ft. up, open 3 in. exposing steel 44 min. spalling to steel on west. 47 min. spalling to steel on north and west near bottom. 55 min. wire tie appeared to be holding concrete between angles in place. 56 min. edge of steel exposed on west from 1 ft. to 6 ft. up, on north from 1 ft. to 2 ft. up. 1 hr., 7 min. steel exposed on south 1 ft. to 2 ft. up. 1 hr., 10 min. large pieces spalled^ on north side near middle of column. 1 hr., 34 min. concrete on lower part of bracket spalled off. 1 hr., 41 min. maximum expansion. 1 hr., 47 min. failure by local buckling about 3 ft. above base. After failure. Coarse aggregate was quite generally broken on fracture planes. Concrete inside of fractures appeared to be in good condition. (Figs. 66 and 112.) Test No. 46. Latticed Angle. '2-in. 1:2:4 trap concrete. 1 hr. diagonal crack, southeast corner at bracket. 2 hr., 35 min. vertical crack, 3 in. long on east face, 4 in. from southeast corner, 8 ft. up. No spalling before failure. 4 hr., 55 min. maximum expansion. 6 hr., 43J^ min. failure with local buckling about 6 ft. above base, each angle deflect- ing outward about 2y 2 in. After failure. Incipient fusion on surface of concrete with small cracks. Concrete crumbly from dehydration to \ l /2 in. from surface. It was other- wise apparently in fair condition except where crushed at point of failure. (Figs. 67 and 117.) Test No. 47. Round Cast Iron. 2-in. 1 :2 :5 cinder concrete. Not tied. 50 min. piece of concrete 2 in. diameter, spalled off under bracket on south exposing bracket; also 6 in. long crack extended down from spall. 2 hr., 3 min. maximum expansion. 2 hr., 42 min. vertical cracks noted on all sides at middle of column. 2 hr., 47 min. concrete fell off from 2 ft. to 10 ft. up, exposing metal. 2 hr. slight deflection to south noted, increasing to % in. at 2 hr., 20 min. 2 hr., 48^4 min. failure with buckling to south, maxi- mum 6 ft. above base. After failure. Column broken up and thickness found to vary from y 2 in. to li^ in. with thinnest metal on north. A short horizontal crack had formed on north side 3 ft. above base. Concrete crumbly for fa in. from surface. Inside of this it appears almost unaffected by the fire test. (Fig. 67, 101 and 158.) LOG OF FIRE, TESTS 151 (e) Hollow Clay Tile Protections Test No. 48. Rolled H. 2-in. semi-fire clay tile, New Jersey district. No filling 7 min. a number of vertical joints open about & in. 12 min. vertical cracks in center of north, east and south sides, 5 ft. to 9 ft. up; cracks in about l /z of all vertical joints. 20 min. vertical cracks extending and in some cases opening to % in.; cracks on all sides at bracket, and lower edge of tile spalled off on southwest corner at bracket. 30 min. north face cracked, 2 ft. to 10 ft. up; vertical cracks on east from 3 ft. to W% ft.; on south from 5 ft. to 9 ft. up; cracks in some cases open 94 in. 1 hr., 15 min. outer shell of tile spalled off along lower west edge at bracket; little change in tile below. No spalling below bracket before failure. 1 hr., 32 min. maximum expansion. 1 hr., 40 min. slight deflection to northwest noted, increasing to ^ in. at 1 hr., 49 min. 1 hr., 50 min. failure, buckling to west, maximum 8 ft. above base. After failure. At failure tile fell off from 5 ft. up to top course of bracket. Lower two or three courses almost intact. (Figs. 68, 118 and 162.) Test No. 49. Rolled H. 4-in. semi-fire clay tile, New Jersey district. No filling 3^2 min. to 8^ min. a number of vertical cracks in tile and joints in lower 8 ft. opened -fe in. to fs in. 12 min. to 24 min. cracks opening to i in. maximum; west face bulged out 3/4. in. from 4 ft. to 8 ft. up. 22 min. ties down at 9th and 12th courses. 25 min. tile in middle section of column, on south and west sides cracked and crushed. 1 hr., 27 min. cracks opening up to % in. in places; no extension of cracks or spalling. 1 hr., 20 min. slight deflection to north noted, increasing to % in. at 1 hr., 38 min. 1 hr., 21 min, maximum expansion. 1 hr., 40 min. failure with compound buckling to northwest 8 ft. above base and to southeast 6 ft. above base. After failure. A few tile intact without cracks; tile generally cracked longitudinally through the shells, not often cracked transversely across webs. This probably accounts for the fact that no spalling of shells occurred until very near failure. (Figs. 68, 118 and 162.) Test No. 50. Plate and Angle. 2-in. surface clay tile, Boston district. Granite concrete fill. (Tile, 6 in. wide, laid horizontally. No ties). 7 min. cracking and spalling on corners, 4 ft. to 6 ft. up. 10 min. tile spalled, concrete exposed on south and east for 1 ft. near bottom. 16 min. tile bulged out on south face from bottom to 6y 2 ft. up. 21 min. tile fell off on south where bulged, exposing steel. 26 min. concrete ex- posed from 4 ft. to 6}4 ft. up on north, east and west. 32 min. cracks open- ing up at joints in upper half. 55 min. maximum expansion. 1 hr., S$4 min, failure with local buckling about 5^ ft. above base. After failure. Tile broke clear from- concrete with no splitting of tile at keys. Transverse shearing of long tile at joints of short tile very marked. Tile in all courses fell in whole or part except top bracket course and three lower courses. Concrete in fill where not crushed by compression ap- parently uninjured (Figs. 68 and 119.) Test No. 50A. Plate and Angle. 2-in. surface clay tile, Boston district. Granite concrete fill. (Tile 6 in. wide, laid horizontally. No ties). 5 min. several horizontal joints open % in.; vertical crack 12 in. long through tile on east face, 6& ft. up; large number of vertical cracks near corners at bracket. 7 min. spall part of one outer shell on each of south and west near middle. 13 min. vertical cracks *4 in. wide opposite joints at all corners. 13 min. to 20 min. outer shell spalled off for 2 ft. at middle on east and west; outer shell bulged out Y 2 in. in several places. 21 min. edge of steel exposed for 6 in. on northeast corner, 6 ft. up. 21 min. to 39 min. tile fell off exposing concrete for 3 ft. at middle on east and west; buckling of tile increasing to & in. maximum; upper 3 ft. intact except for y & -m. cracks at bracket. 1 hr., 14 min. tile fell off exposing concrete in lower 3 ft. on west face; otherwise little change. 1 hr., 24 mm. mortar joints evidently not very full on north and south, can see through in places. 1 hr., 42 min. tile buckled out 1 in. north, 5 ft. up. 1 hr., 44 min. maximum expansion. 1 hr., 59^ min. failure, buckling to west, maximum 5% ft. above base. 152 RESULTS OF FIRE TESTS After failure. All tile fell off at failure except parts of courses in lower foot and in upper three feet. Concrete fully fills re-entrant portions except where crushed out at point of failure. (Figs. 69, 119 and 163.) Test No. 51. Plate and Angle. 4-in. surface clay tile, Boston district. Granite concrete fill 7 min. to 17 min. considerably cracking and bulging, mostly in middle courses, where some corners were shattered. 14 min. vertical cracks in about 50 per cent of tile. 18 min. to 38 min. bulging increasing, vertical cracks opening to Y$ in, maximum; minor spalling on southeast and south- west corners in middle courses. 20 min. ties on 2nd and 8th courses down. 36 min.- tie on 6th course down. 40 min. to 52 min. outer shell of tile spaljed off from 5 ft. to 7 ft. up on south and west. 1 hr., 22 min. bulging of tile increased to 1^ in. maximum. 1 hr., 47 min. tile fell on north, to 7 ft. up exposing mortar and concrete. 1 hr., 30 min. slight deflection to west noted, increasing to ^ in. at 2 hr. 2 hr., 11 min. maximum expansion. 2 hr., 17*/i min. failure, buckling to west, maximum 6 ft. above base. After failure. Tile generally shattered. Parts of tile near bottom blackened and partly fused by the heat. Concrete fills web spaces fairly; it is apparently little injured. Mortar joint on flanges not full in, places but voids are partly filled with concrete. (Figs. 69 and 120.) Test No. 51A. Plate and Angle. 4-in. surface clay tile, Boston district. Granite concrete fill 3 min. to 15 min. considerable cracking and some bulging at corners. 16 min. cracks quite general, open to % in. in lower two-thirds, not over t"g- in. above. 16 min. to 44 min. cracks increasing and opening up; bulg- ing out of tile at horizontal joints to maximum of 2 in., mostly in middle four courses. 38 min. tie broken on 5th .course. 1 hr., 6 min. cracks and bulges opening up in lower 8 ft.; little change above. 1 hr., 14 min. ties dropped on 2nd and 3rd courses. 1 hr., 20 min. to 1 hr., 32 min. outer shells on east and west side in middle course spalling; at end of this period tile had fallen exposing concrete from 4 ft. to 8 ft. up on east and from 4 ft. to 10 ft. up on west. 1 hr., 44 min. all ties down except on 3 upper courses. 1 hr., 45 min, tile buckled away from flanges on north and south, 6 ft. up. 2 hr., 6 min. tile spalled on north, 6 ft. up, exposing east flange 3 by 4 in. 2 hr., 23 min. tile buckled away from flanges on north and south, 8^2 ft. up. 2 hr., 26 min. no change in upper courses. 2 hr., 40 min. maximum expansion. 2 hr., 54 min. tile fell on south, 6 ft up, exposing steel. 2 hr., 41 min, lateral deflection at center less than Y% in. 2 hr., 55^ min. failure with buckling to west, maximum at 5^2 ft. above base. After failure. Upper 2y> courses almost intact except for spalling of part of outer shell on west. Tile generally cracked through shells parallel with webs, but some were also cracked through webs parallel with shells. Filling good, no voids. Tile fused near bottom on south and west sides, some pieces had been nearly plastic. Partial fusion extended up to the 10th course. (Figs. 69, 120 and 163.) Test No. 52. Plate and Channel. 2-in. Ohio shale tile, Cinder concrete fill. 2 min. cracks ]/s in. wide on east and west. 8 min. to 11 min. cracks increasing and open to *i in., some shells buckling, two outer shells spalled, and considerable number of outer shells loose. 16 min. cracks open to 1 in. maximum; tie broken on 7th course. 18 min. outer shell 7th course on west spalled off. 27 min. tie broken on 9th course. 32 min. outer shell 9th course on south spalled; a number of loose outer shells held in place by ties. 53 min. all tile cracked but little further spalling. 1 hr., 6 min. edge of southeast flange exposed opposite 6th course. 1 hr., 25 min. inner shell ready to fall on 7th course, west, edges of flanges probably exposed. 1 hr., 32 min. maximum expansion. 1 hr., 40^4 min. failure with local buckling about 6 ft. above base. After failure. Concrete. fill without voids; motar joints on north and south sides fairly full. Bracket courses almost intact. (Figs. 70, 121 and 163.) LOG OF FIRE TESTS 153 Test No. 53. Plate and Channel. 4-in. Ohio shale tile. Cinder concrete fill. 2 min. to 15 min. cracking very pronounced on all faces, cracks open- ing up to 1 in. maximum at end of this period. 7 min. to 30 min, spalling of outer shells beginning at corners and later across faces; outer shells generally loose. 8 min. to 23 min. bulging out of tile at horizontal joints on east and west, 3 ft. to 9 ft. up, increasing to \ l / 2 in. at end of period. 24 min. ties off on 3rd, 7th,' and 9th courses. 30 min. to 33 min. all outer shells spalled off on west, 2 ft. to 6 ft. up, on east, 9 ft. to 10 ft. up. 33 min. to 37 min. tile fell on west, 4th and 5th courses, on east 7th, 8th and 9th courses. 42 min. all ties down except on 1st, 8th llth and 12th courses. 45 min. tile bulged out on south exposing steel from 2 ft. to 5 ft. up. 58^ min. tile now fallen on west from 3rd to 9th courses, incl. 1 hr., 4 min. bracket courses nearly intact. 1 hr., 17 min. maximum expansion. 1 hr., 22% min. failure with local buckling about 7 l / 2 ft. above base. After failure. Cracks through tile webs parallel with faces predominate, although many units cracked through both faces. Mortar joints generally full. Concrete fill good, no voids. (Figs. 70, 121 and 163.) Test No. 54. Latticed Channel. 2-in. Ohio semi-fire clay tile. Trap con- crete fill 2 min. to 15 min. considerable cracking, both in. joints and in tile, cracks opening up generally to J-6 in. at end of period; outer shells spalling near corners and beginning to bulge out at horizontal joints, mostly in middle courses. 24 min. bulging out of outer shells increased to maximum of 2 in. 28 min. tie broken on 9th course. 48 min. nearly all of outer shells spalled off at bracket on south. 50 min. to 1 hr., 4 min. outer shell of tile spalled on south, 4 ft. to 5 ft. up, on north half of east face, 3 ft. to 5 ft up, and on west 7 ft. to 9 ft. up. 1 hr., 22 min. tie broken on 4th course. 1 hr., 4\y 2 min. inner shells on east fell, 4 ft. to 6 ft. up, exposing steel; 1 hr., 43 min. inner shells on north fell, 4 ft. to 6 ft. up, exposing steel; outer shell spalled on north, 3 ft. to 4 ft. up. 1 hr., 52 min. tile fell on west 2 ft. to 4 ft. up exposing flange edges; on north, 3 ft. to 6 ft. up, exposing part of flanges and lattice. 2 hr. 30 min. all tile off on west, 9th and 10th courses. 2 hr. slight deflection to northwest noted, increasing to J^ in. at 2 hr., 41 min., and to 1 in. west at 3 hr., 1 min. 2 hr., 20 min. maximum expansion. 3 hr., 17% min. failure, buckling to west, maximum 6 ft. above base. After failure. Concrete between flanges of channels quite crumbly; that between channel webs hard and apparently little injured except where crushed. Concrete fairly fills space between steel and tile on both flange and web sides. (Figs. 70, 122 and 164.) Test No. 55. Z-bar and Plate. 2-in. Ohio semi-fire clay tile. Limestone concrete fill 4 min. cracking and bulging out of outer shells. 13 to 23 min. outer shells generally cracked to Y& in. maximum; bulging out at horizontal joints increasing; some spalling at corners. 34 min. parts of shell on west spalled at 4 ft. to 5 ft. and 2 ft. to 3 ft. up. 45 min. all cracks opening. 1 hr., 4 min. wire tie broken on 3rd course. 1 hr., 48 min. tile fell on west, 7th to 10th courses inch, also part of 9th course on south fell. 2 hr. outer shell spalled on south at bracket course exposing edge of bracket steel 2 hr., 8 min. outer shell spalled on north 7th to 9th course. 2 hr., 37 min. tile bulged out to 1J4 in. on south, 9 ft. up. 2 hr., 51 min. maximum expan- sion. 3 hr., 20 min. tile fell on west llth course. 3 hr., 23 min. to 3 hr., 27 min. outer shells spalled on north at bracket and from 2 ft. to 6 ft. up; on east, shells now spalled from 2 ft. to 7 ft. up. 3 hr., 41 min. deflection of */s in. south. 3 hr., 46-)4 min. failure, buckling to south, maximum at 8 ft. above base. After failure. Tile shells remaining on are firmly held. Concrete filled interior fully, including space between Z-bar flanges and tile. Concrete hard where tile remained in place; where exposed, concrete was calcined to depth of about tf in. (Figs. 71, 122 and 164.) 154 RESULTS OF FIRE TESTS Test No. 56. Z-bar and Plate. 4-in. Ohio semi-fire clay tile. Limestone concrete fill 5 min. to 30 min. considerable cracking and some spalling of parts of outer shells; spalling principally in upper half near southwest corner, at middle near northwest corner, and on lower courses at northeast corner. 57 min. outer shell bulged slightly at some horizontal joints, most on west at 6 ft. and 7 ft. up; no inner shells spalled. 2 hr.-, 30 min. maximum expan- sion. 2 hr., 55 min. outer shell spalled on south at bracket; otherwise little cracking or spalling in last 2^2 hr. ; wire mesh in horizontal joints holding tile in place quite effectively. 1 hr., 51 min. deflection of % in. south; deflection changed to ^ in. northeast at 3 hr., 1 min., increasing to Y% in. at 3 hr., 21 min. 3 hr., 33^> min failure, buckling to north, maximum at &/ 2 ft. above base. After failure. Wire mesh in all horizontal joints lapping at corners. Concrete fill good, no voids; concrete hard, almost intact. (Figs. 71, 123 and 165.) Test No. 57. I-beam and Channel. 4-in. surface clay tile, Chicago district* Limestone concrete fill 3 min. to 13 min. general cracking and bulging of a few outer shells, cracks open to r /i in. 23 min. bulging increasing; general spalling of small pieces from corners. 25 min. parts of outer shell spalled on east and west, 4 ft. to 5 ft. up. 32 min. cracks and bulges generally open ^ in. on all sides from 3 ft. to 6 ft. up. 38 min. outer shells loose or fallen on west, 5 ft. to 7 ft. up and on south 4 ft. to 6 ft. up. 53 min. all outer shells spalled on, east and south, 3 ft. to 6 ft. up, and on north, 5 ft. to 6 ft. up; tile in 5th course on south fell, exposing part of flange. 1 hr., 2 min. large amount of tile fell on all sides exposing most of concrete from 3 ft. to 10 ft. up. 2 hr., 15 min. maximum expansion, 2 hr., 37 min. tile down on all sides from 2 ft. to 12 ft, up, exposing concrete. 2 hr. slight deflection to north noted, increasing to *A in. at 2 hr., 50 min., and to ^ in. at 3 hr., 21 min. 3 hr., 23 min. failure, buckling to north maximum at 8 ft. above base. After failure. A number of tile sheared at -plaster key, leaving latter in the concrete. Concrete fill fairly full except at a few points between tile and channel flange. Concrete calcined to depth of ]/> in. where exposed; hard where protected. (Figs. 71 and 123.) Test No. 58. I-beam and Channel. 2 layers of 2-in. surface clay tile, Chi- cago district. Tile fill. Wire mesh in horizontal joints 3 min. to 15 min. outer shells and tile spalled at corners quite generally. 16 min. outer shell of outer tile bulged out 1^2 in. at horizontal joint on east, -5 ft. up. 26 min. part of inner shell of outer layer of tile at south- east corner, 10 ft. up fell; outer shells continuing to spall at corners and on parts of some faces. 44 min. to 48 min. outer shells of outer tile spalled on all sides at bracket, also partly on east, at 10 ft. up, and all on west, 10 ft. to 11 ft. up; outer shell bulged 1 in. at 10^ ft. up on south. 1 hr., 36 min. all outer shells now spalled on east from 9 ft. to top. 1 hr., 57 min. outer tile down on south, 10th course and on east, 9th course. 3 hr. little change in 1 hr. 3 hr., 30 min. outer shell of outer tile spalled on south, 5th course. 3 hr., 43 min. bracket exposed for 6 in. on northeast. 3 hr., 45 min. all tile down in upper two courses on east; on north and south, outer tile down in upper two courses and inner tile bulging out 1 in.: all of bracket exposed on both sides. 3 hr., 56 min. 50 to 75 per cent of outer shells of outer tile now down, most of which occurred before 1 hr., 57 min.; total outer tile and part of inner tile fallen in a few places as noted above; little spalling now taking place. 4 hr. maximum expansion. 4 hr., 25 min. no decided change; no fusion noted although tile at 4 ft. up concave outwards as if beginning to fuse. 3 hr. slight center deflection to south noted, increasing to % in. at 4 hr., 31 min. 4 hr., 35^4 min. failure with local buckling to south and west about 11 ft. above base. LOG OF FIRE TESTS 155 After failure. Generally all but outer shell of outer tile in place in lower eight courses. On 9th course outer tile down and almost all tile down in 10th, llth and 12th courses. Wire mesh found in all joints except between the 1st and 2nd courses, between the 9th and 10th on north and south where the pipes interfered, and between the llth and 12th where the bracket angles interfered. Some mesh was found between the 10th and llth course although so much tile was down that it was impossible to determine whether all pieces had been placed. Very decided fusion of tile occurred in lower 4 ft. and incipient fusion up to 7 ft. above base, being most pro- nounced on south side of column. (Figs. 71, 124 and 165.) Test No. 59. I-beam and Channel. 2 layers of 2-in. surface clay tile, Chicago district. Tile fill. Outside wire ties. 3 min. to 14 min. considerable cracking of outer shells on all sides. 14 min. outer tile bulged out 1J/2 in. on west, 7 ft. up. 15 min. to 23 min. spalling of two outer shells at corners. 17 min. outer tile bulged out y* in. on north, 4 ft. up, increasing to 2 in. at 27 min. 26 min. nearly all of outer shells of outer tile spalled on west, 6 ft. to 8 ft. up; tie broken on 8th course. 29 min. outer shell spalled on east, 7th and 8th courses. 33 min. all outer tile, 8th and 9th courses, down and part of tile in 7th course. 35 min. inner tile bulged out 2J4 in. on west, 7 ft. up. 36 min. outer tile loose on west in llth and 12th courses, held by wire. 38 min. all outer tile down on south from 3 ft. to 6 ft. up, on north from 3 ft. to 8 ft. up. 42 min. inner tile on south bulged out $4 i R -> 5 ft. up. 1 hr., 6 min. inner tile down on south, 6 ft. to 9 ft. up, exposing both flanges. 1 hr., 16 min. all outer tile and parts of inner tile down except for parts of upper and lower courses. 1 hr., 23 min. all tile down on west, 6 ft. to 8 ft. up, ex- posing channel. 1 hr., 25 min. maximum expansion. 1 hr. slight center deflection to north noted, increasing to 2i in. at 1 hr., 31 min. 1 hr., 33% min. failure with buckling to north, maximum at 7 l / 2 ft. above base, and twisting about 22 After failure. ' All but filling tile down in middle six courses. Filling tile also thrown off near middle of column. All tie wires broken before or at failure. (Figs. 72 and 124.) Test No. 60. Latticed Angle. 2-in. Ohio semi-fire clay tile. Trap concrete fill, placed before tile was set 3 min. to 18 min. cracking of tile on all sides; vertical crack on north near west corner open to % in., 3 ft. to 6 ft. up. 13 min. to 18 min. tics broke on 9th, 6th, 8th, 4th and 3rd courses, in the given order. 18^ min. part outer shells spalled on south, 3 ft. to 6 ft. up. 26 min. tile down on west from 1 ft. to 7 ft. up, exposing concrete. 32 min. tile bulged out 2 in. on north, 2 ft. to 6 ft. up. 33 man. tile down on north from 1 ft. to 6 ft. up. 36 min. tile bulged out \ l / 2 in. on east, 2 ft. to 7 ft. up. 38 min. a few cracks in tile in upper three courses. 40 min. all tile down on east, 1 ft. to I0y 2 ft. up. 48 min. tile down on north, 7^4 ft. to 10^ ft. up. 1 hr., 2 min. tile down on south, 7th course. 1 hr., 47 min, maximum expansion. 1 hr., 58 min. little change during last hour. 2 hr., 7 min. all tile down on south up to bracket. 2 hr., 13 min. & in. vertical cracks in concrete half way up increasing to ^ in. at 2 hr., 24 min. 2 hr., 21 min. center deflection of Yz in. northwest, increasing to ft in. at 3 hr., 7 min. 3 hr., 9 l / 2 min. failure with local buckling 4^ ft. to 5 ft. above base. After failure. Tile quite generally cracked vertically through both shells, transverse cracks along webs not general. Mortar evidently did not bond tile and concrete. Except at point of failure, cracks in concrete are not wider than & in. Concrete very crumbly outside lattice, quite hard inside. (Figs. 72, 125 and 166.) 156 RESULTS OF FIRE TESTS Test No. 61. Latticed Angle. 2-in. Ohio semi-fire clay tile. No filling 3 min. to 18 min. pronounced cracking and bulging especially at middle courses; cracks mostly vertical, opening to 1% in maximum on south, 5 ft. to 7 ft. up; very little spalling. 13 min. ties broken on 4th, 6th and 7th courses. 26 min. both outer and inner shells fell on northwest corner. 4 ft. up, for width of about 4 in. 32 min. similar spall on southeast corner, 4 ft. up. 35 min. considerable bulging of tile on south, 3 ft. to 4 ft. up. 44 min. cracks and bulging increased slightly, none now more than J4 m - 45 min. maximum expansion. 47 min. center deflection of l /4 in. east. 50J4 min. failure with local buckling about 6 ft. above base. After failure. Tile cracked transversely in some cases; greater number cracked vertically through both faces without transverse web cracks. (Figs. 73 and 125.) Test No. 62. Round Cast Iron. 2-in. porous semi-fire clay tile, New Jersey district; no filling Air pressure tanks shut off, load applied by. water pressure only. 6 min. to 20 min. a number of vertical cracks in tile and in mortar joints, opening to maximum of J4 i n - at end of this period. 45 min. cracks now in 40 to 50 per cent of tile units, width varying from fine to ^ in. in column proper, and to l /2 in. at bracket. 2 hr. all ties in place; cracks have opened up slightly. 2 hr., 25 min. horizontal cracks on west between bracket courses about fff in. wide. 2 hr., 42 min. similar cracks on southwest, l / 2 in. wide. 3 hr. maximum expansion. 3 hr., 26 min. horizontal bracket cracks open to 1 in. maximum. 4 hr., 10 min, cracks open 1 in. at middle of column; no spalling or bulging of tile. 4 hr. slight deflection to southeast noted, increasing to 1^ in. at 4 hr., 10 min. 4 hr., 11^ min. failure, column unable to support working load. 4 hr., 13 min. load of about 75,000 Ib.held. 4hr., 14 min. tile fell on east; load of about 25,000 Ib. held. 4 hr., 1454 min - gas snut off- Column buckled to southeast, maximum at 8 ft. above base. After failure. Column did not crack although metal buckled near sur- face on compression side at failure point. Cracks in tile are generally ver- tical, extending through both shells. Tie wires were greatly oxidized and had little strength. (Figs. 73, 126 and 167.) Test No. 63. Round Cast Iron. 2-in. porous semi-fire clay tile, New York district. No filling 6 min. vertical crack on east, 4 ft. to 5 ft. up, & in. wide. 8 min. to \\ l / 2 min. gas shut off accidentally during this period. 13^ min. to 23^ min. fine vertical cracks 2 ft. to 6 ft. long opening up to 1 A in. maximum. 32 min. outer strell loose on 3rd course, east side. 35 min. cracks open to l /z in. 47^ min. cracks open to % in. maximum. 1 hr., 25 min. cracks opened but slightly during past 30 min, 1 hr., 37 min. some flaking of outer shells; no spalling. 1 hr., 55 min. very little change; tile above 10 ft. up almost intact except for a few cracks j in. wide. 2 hr., 20 min. maximum expansion. 2 hr., 23 min. about l /z of outer shell spalled on 3rd course, east side. 2 hr., 24 min. bulging on southeast, 4 ft. to 6 ft. up, with spalling of parts of both shells leaving crack 34 in - to 2 in. wide. 2 hr., 41 min. slight center deflection to north, increasing to 1J4 i n - at 2 hr., 55 min. 2 hr., 57^ min. failure with buckling to north, maximum at 5y 2 ft. above base. After failure. Most cracks in tile were vertical, straight through both shells. Tie wires greatly oxidized, leaving ik in. effective diameter. At failure point S 1 /^ ft. up, cast iron was mushroomed out about 1 in. for one- half the circumference in a height of 2^ in. Numerous vertical cracks in the iron formed in this region. Tension breaks extend for one half of the circumference on south, Z l / 2 ft. above the base and 1^4 ft. below the head. The thickness of metal at the center break varied from ^ in. to 1^4 in., the thinnest metaT being on the south. (Figs. 73, 126 and 167.) LOG OF FIRE TESTS 157 Test No, 76. Rolled H. 2-in. hollow clay tile covered with 94-in. layer of gypsum plaster; limestone concrete fill. Upper 4 courses, Ohio shale; middle 4 courses, Ohio semi-fire clay; lower 4 courses, semi-fire clay, New Jersey district 1 min. to 3 min. outer coat of plaster peeled off and shattered at end of this period; vertical cracks extending through to tile in places. 10^ min inner coat of plaster fell on south exposing tile 3 ft. to 8 ft. up. 11 min. to 32 min. inner coat of plaster fell exposing about two-thirds of tile at 21 minutes; at 32 min. about 90 percent of plaster had fallen below bracket course; plaster still on bracket on all four sides and down to 9 ft. up on west. 28 min. to 1 hr. 10 min. some spalling of outer shells and very slight amount of cracking, mostly at corners; at end of this period north- east corner was spalled, 5 ft. to 6 ft. up, also on west, 4 ft. to 5 ft. up and on east, 6 ft. to 7 ft. up; shell loose on north 7 ft. to 8 ft. up. 1 hr., 32 min. several corners spalled in upper two-thirds of column. 1 hr., 41 min. outer shell spalled on north 8th course; plaster on at bracket except on north side. 2 hr., 30 min. little change during past 50 min. except for a few spalls of outer shells in. upper half. 3 hr., 30 min. no change except outer shell spalled on west 9th course. 3 hr., 45 min. maximum expansion. 4 hr. little change except for a few vertical cracks, tt in. to l /% in., near top; plaster still on parts of bracket. 4 hr., 18 min. outer shell spalled on east, 9th course; no inner shells spalled before failure; no spalling of outer shells on four lower courses. Deflections not measured. 4 hr., 25^2 min. . failure with local buckling about 9 l / 2 ft. above base. After failure. Shale tile almost all off, could not be examined; Ohio semi-fire clay tile, quite shattered, no bond with mortar or fill; semi-fire clay, New Jersey district, tile in fairly good condition except for a number of fine cracks; fair bond with fill. Concrete fill full, no voids. Mortar joints on sides were fairly full. (Figs. 78, 138 and 46.) Test No. 77. Plate and Angle. 4-in. hollow clay tile covered with 54-in. layer of lime plaster; limestone concrete fill. Upper 4 courses, semi-fire clay, New Jersey district; middle 4 courses, surface clay, Chicago district; lower 4 courses, surface clay, Boston district. y 2 min. most of plaster spalled off exposing nearly three-fourths of total tile surface. 15 min. practically all of plaster down except small amount in places near top; some outer shells of tile beginning to buckle in middle courses. 20 min. to 50 min.. cracking and some spalling of outer shells, mostly at corners, in mdidle four courses; a few cracks in lower 4 courses, less than i% in wide. 1 hr., 10 min. very little change during 2( min., though cracks opened slightly; no cracks observed in upper 4 courses. 1 hr., 35 min. a few fine cracks in upper 4 courses, not over & in. 1 hr., 49 min. a number of horizontal cracks in lower 4 courses up to ^ in. wide; outer shell spalled on west, 3 ft. to 4 ft. up. 2 hr., 20 min. horizontal and vertical cracks in lower 4 courses opening up */s in. to t\ in. Cracks in upper 4 courses not opening up. 3 hr., 22 min. a few tile in lower courses curved out, splitting near ends; not much change in middle 4 courses. 4 hr. cracks in lower 4 courses open & in. to */ 2 in.; northeast corner spalled, 2 ft. to 3 ft. up; possible fusion 3 ft. up. 4 hr., 10 min. maximum expansion. 4 hr., 17 min. more spalling of outer shells in middle courses; no inner shells spalled. 4 hr., 20 min. tile bulged out from steel just above middle on north and south sides; very decided fusion, 1 ft. to 3 ft. up. 4 hr., 26 min. cracks in lower 4 courses open & in. to y 2 in.; outer shell 5th to 7th course, north side, spalled; cracks in upper 4 courses open not over & in. 4 hr., 26 min. to 4 hr., 30 min. considerable spalling of outer shells in middle 4 courses. All inner shells, all courses, in place before failure. Deflections not measured. 4 hr., 42J4 min. failure with buckling to west, maximum at 6 ft. above base. 158 RESULTS OF FIRE TESTS After failure. All of upper four courses and middle four courses of tile down, examination not possible. Lower four courses much shattered Sy vertical and horizontal cracks; incipient fusion through outer shells and through webs where exposed; pieces of this tile bent, curled and discolored. Concrete fills reentrant portions fully. Appearance of steel indicated that concrete had not fully filled space between flanges and tile. (Figs. 78, 139 and 46.) (f) Gypsum Block Protections Test No. 64. Rolled H. 4-in. Western gypsum block (solid). Hollow gypsum block fill 10 min. fine surface checks developing, about 1/32 in. wide. 30 min. fine surface checks all over faces, about J in. apart both ways. 48 min. corners spalled not over J^ in. by ^ in. 1 hr. very little change. 1 hr., 30 min. surface checks about l /% in. wide by J^ in. deep; a few vertical joints opened not over 1/32 in. 2 hr., 30 min. both horizontal and, vertical joints opened about l /% in.; motar joints project l /^ in. 2 hr., 40 min. block fell from bracket on north exposing west part of bracket steel. 3 hr., 10 min. to 3 hr., 25 min. spalling on southwest and northeast corners, just below middle, to 2 in. back. 3 hrs., 35 min. surface checks Y% in. wide by y 2 in. deep; all cracks open to about J4 m - 3 hr., 45 min. mortar joints through- out project about l / 2 in. 3 hr., 55 min. piece of block down on southwest side of bracket; blocks on northeast and southeast sides of brackets stand out. 4 hr., 5 min. block down on northeast side of bracket, exposing rest of bracket steel. 4 hr., 10 min. mortar joints project 1/4 in. Tile appears to be about 3 in. thick. 4 hr, 15 min. block down on southeast side of bracket; both sides of south bracket now exposed; bracket steel glowing dull red. 4 hr., 20 min. blocks on east and west faces tilting out from steel at 7 ft. up; 'surface checks appear to be about 1 in. deep. 4 hr., 30 min. nearly all of block down on west, 6 ft. to 7 ft. up; all fell on east, from 4 ft. up to top of column, on south from 4 ft. to 6 ft. up, exposing flange foi 5ft., also down on north, 10 ft. to 11 ft. up. 4 hr., 32 min. maximum ex- pansion. 4 hr., 39 min. all blocks down on west from 1 ft. up to top. 4 hr., 30 min. slight deflection to northeast noted, increasing to ^ in. at 4 hr., 41 min. 4 hr., 43J4 min. failure with buckling to east, maximum at 5 ft. above base. After failure. Exposed column flange on south greatly oxidized during test. Gypsum blocks shrunken to thickness of 3J4 in. to 3J/2 in. Surface of blocks checked into l /4 in. squares, cracks extending inward to depth of \Y$ m. to 2 in. from surface on sides and to Z l /2 at corners, the corner cracks extending in diagonally. Gypsum in this zone is brownish green. Further in gypsum is much more crumbly than new material, showing that the heat had affected ",t. (Figs. 74 and 127.) Test No. 65. Plate and Channel. 2-in. Western gypsum block (solid). Solid gypsum block fill 11 min. fine surface checks beginning to develop. 23 min. a few fine cracks and slight corner spalls; surface checks more distinct, forming in l / 2 in. squares. 29 min. a few vertical joints open j% in. 48 min. surface checks iV in. wide by y\ in. deep, distinct throughout courses; cracks J^ in. deep; some corners spalled y 2 in. back, corners generally ragged. 1 hr., 5 min. cracks in all joints about & in. wide; surface checks J^ in. wide. 1 hr., 30 min. shrinking of tile apparent, mortar joints project & in. to % in. Cracks in joints now ^ in. wide. 1 hr., 45 min. block fell on west 4 ft. to 5 ft. up, exposing edges of flanges. 1 hr., 49 min. block fell on south, 5 ft. to 6 ft. up; mortar in joints projects out generally, % in- to % in. 2 hr. blocks fell on north, 2 ft. to 6 ft. up, steel still covered by mortar. 2 hr., 5 min. blocks fell on east, 2 ft. to 6 ft. up, on west 2 ft. to 5 ft. up; three top courses still intact. 2 hr., 9 min. blocks down on south and west, 5 ft. to 6 ft. up. 2 hr., 10 min. edges of flanges exposed where blocks have fallen but steel plates are covered with s about 1 in. of mortar in all cases. 2 hr., 12 min. block down on west 6 ft. to 7 ft. up; piece fallen LOG OF FIRE TESTS 159 on northwest corner at bracket. 2 hr., 17 min. mortar in joints projects Y% in. 2 hr., 20 min. maximum expansion. Mortar fallen on north ex- posing steel; blocks down on north and west 7 ft. to 8 ft. up. 2 hr., 11 min. center deflection less than ^ in. 2 hr., 21 1 / 2 min. failure with local buck- ling about 3 ft. above base. After failure. Blocks shrunken to thickness of \y 2 in. to 1^4 in. Sur- faces of blocks checked into l / 4 in. to ]/ 2 in. squares, cracks being & in to % in. wide at surface and y 2 in. to ft in. deep on sides; cracks at corners extend in diagonally 1 in. to 1}4 in. Outer dehydrated surface quite firm and greenish in color in places; hardness extends to inner zone of checking where color changes from white to brownish. Gypsum further in is softer than material not exposed to fire. Galvanizing on corrugated sheet metal ties placed in the joints was removed, otherwise they were not oxidized or corroded. (Figs. 74 and 128.) Test No. 66. Latticed Channel. 2-in. Eastern gypsum block (solid). Poured gypsum filling 15 min. fine surface checks beginning to develop. 30 min. to 40 min. surface checks more distinct, forming in ^4-in. to 1-in. squares, mostly in lower half. 1 hr., 15 min. joints open to & in. increasing to % in. at 1 hr., 35 min. 1 hr., 35 min. mortar in joints projects fs in. 2 hr. surface checks now cover whole surface, and are *4 in. to y 2 in. in depth; joints open to y% in. maximum. 2 hr., 5 min. block on east 5 l / 2 ft. up tilting out ^ in, at top. 2 hr., 14 min. small spall on southwest corner at bracket, block below bracket on west tilting out at top. 2 hr., 15 min. block down on east in 4th course exposing lattice bars where unprotected by filling. 2 hr v 22 min. block fell on east 8'th course, exposing steel. 2 hr., 26 min. blocks fell on north, \ l / 2 ft. to S l / 2 ft. up, exposing steel. 2 hr., 30 min. block fell on south, 4th course up, exposing steel. 2 hr., 32 min. maximum expansion. Blocks fell on south and west 2nd course up. 2 hr., 33 min. center deflec- tion less than % in.' 2 hr., 36 min. failure with local buckling about Zy 2 ft. above base causing column to deflect to west. After failure. Filling fairly full, but has some pockets, 2-in. deep; filling extends out between lattice bars but not much beyond; very crumbly where exposed. Blocks shrunken to thickness of 1^ in., little change in color. Surface checks are A in. wide at surface and l / 2 in. to 1/4 in. deep. Strips of wire mesh in joints not greatly oxidized. (Figs. 74 and 128.) Test No. 67. Rolled H. 4-in. Eastern gypsum block (solid). Poured gypsum filling 17 min. fine surface checks, forming in 1-in. squares beginning to show. 34 min. surface checks more marked, 1/32 in. to ^ in. wide; checking most pronounced in lower half. 1 hr., 5 min. surface checks *A in. deep and % in. to l /4 in. wide; corner cracks y 2 in. to 1 in. deep and 1 in. to 2 in. long 1 hr., 20 min. joints beginning to open up; several horizontal cracks 1 in. deep across faces; surface checks now forming in y 2 in. to 24 in. squares. 1 hr., 50 min. very little change; surface checks y* in.^to l / 2 in. deep are general. 2 hr., 10 min. a few mortar joints project T"B in. to l /% in. 2 hr., 21 min. pieces of corners at bracket spalled. 2 hr., 40 min. joints open to l /% in. Surface checks 3^ in. deep and l /4 in. wide. 3 hr., 45 min. mortar in joints projects J4 in., vertical joints open to % in., little change in surface checks. 4 hr., 40 min. mortar projects to l / 2 in., otherwise little change. 4 hr., 52 min. top of block tilts out in 1 in. on north Sy 2 ft. up. -4 hr., 54 min. blocks fell on south 3rd and 4th courses, mortar still covers steel quite generally; piece of block 4 in. wide also down at^ southwest corner in ^5th course; joints near top open A in. 5 hr., 1 min. maximum expansion. 5 hr., 5 min. blocks next to those fallen tilt away from steel; steel now ex- posed on south 3 ft. to 4 ft. up. 5 hr., 7 min. blocks down on west 3rd to 6th course exposing filling and flange edges. 5 hr., 13 min. block fell on west 2nd course; west edge of flange exposed 4 ft. to 6 ft. up; little change after this until failure. 5 hr., 31^ min. failure with local buck- ling about 4 ft. above base. 160 RESULTS OF FIRE TESTS After failure. Fill fairly full but has some pockets 2 in. deep; mortar where still in place, covers flanges ^ in. to 1 in. Steel fluxed for 30 in. length near point of failure; edges of flanges attacked where exposed, un- affected where not exposed; strips of wire mesh oxidized through where they had been exposed to the fire. Blocks shrunken to thickness of 3^ in. to 3^ in. Surface check cracks formed in y$ in. to l /2 in. squares, cracks T^ in. to tk in. wide at surface and generally 2 in. deep, although some ex- tend completely through blocks; radial cracks at corners 2J4 m - deep. Block colored brownish yellow in outer 1 in., further in stained dark from oxidiza- tion of wood fibre. (Figs. 75 and 129.) Test No. 67 A. Rolled H. 4-in. Eastern gypsum block (solid). Poured gypsum filling 15 min. fine surface checks beginning to show; fine cracks on ends of blocks. 45 min. surface checks forming in ^ in. to 1 in. squares, most pro- nounced on west 1 hr., 30 min. vertical joints opening slightly. 2 hr. cracks in both vertical and horizontal joints opening up perceptibly; surface checks Y in. deep. 3 hr. vertical joints near middle of column open to YA, in. 3 hr., 30 min. all joints open from ]/% to Y in. Mortar joints project Y$ in. Minor spalling from corners. 4 hr. all blocks have shrunk consid- erably; joints open Y% in. to *4 in. 4 hr., 30 min. small pieces spalling from corners; larger piece fallen from northwest corner, 7 ft. up. 5 hr., 15 min. edge of bracket steel exposed on south side. 5 hr., 15 min. to 5 hr., 45 min considerable spalling at corners. 5 hr., 45 min. maximum expansion. 5 hr., 56 min. blocks fell on north in 2nd and 3rd courses, and on west 2nd course; steel exposed. 6 hr., 14 min. blocks now down on north from bottom to 5^ ft. up. 6 hr., 20 min. blocks down on east 2nd course and on south- 3rd course. 6 hr., 21 min. block down on west 7th course. 6 hr., 10 min. slight deflection to southwest increasing to Y in. at 6 hr., 16 min. 6 hr., 24^2 min. failure with buckling to south, maximum at 4^4 ft. above base. After failure. Filling fairly full. Column flange on north greatly oxid- ized for 3 ft. near point of failure. Blocks shrunken to thickness of 3^ in. to 3^ in., gypsum very crumbly. Surface checks Y^ in. wide, extend in to depth of 2% in. (Figs. 75 and 130.) (g) Brick Protections Test No. 68. Rolled H. 2%-in. Chicago common brick laid on edge. Brick fill 13 min. a number of irVin. cracks in joints. 15 min. some cracking and spalling at corners. 16 min. to 18 min. several vertical cracks devel- oping in middle sections, one on north face ^ in. wide, 2 ft. long. 23 min. brick fell on east from 3^2 ft. to 8^ ft. up, exposing north flange to depths of from 1 in. to 3 in. back from edge. 26 min. brick fell on west, 4 ft. to ^Yz ft. up exposing south flange for width of 1 in., bricks bulged out Y^ in. from flanges on north and south in this region increasing to y 2 in. at 36 min. 36 min. brick in upper third cracked somewhat; brick almost intact up to 3y 2 ft. above base. 1 hr., 4 min. very little change, bulging in middle slightly increased 1 hr., 10 min. maximum expansion. 1 hr., 20 min. slight deflection to southeast noted, increasing to Y^ in. at 1 hr., 37 min. 1 hr., 40^4 min. failure with local buckling 6^ ft. to 8 ft. above base. After failure. Brick soft and crumbly and cracks readily. Mortar joints apparently quite full. (Figs. 76, 118 and 166.) Test No: 69. Rolled H. 3^-in. Chicago common brick laid flat. Brick fill. First Test Trouble with one gas burner developed soon after start of test and gas was shut off at 37^4 rnin. Test postponed for two days. Column ob- served after test was discontinued. One-half to two-thirds of brick cracked through vertically in one or more places, cracks from very fine to 3s in. wide. Slight flaking and spalling of corners noted. Temperature of steel at end of test 45 C., attaining a maximum of 140 C., 3 hr., 20 min. later. Second Test 1 hr., 30 min. slight flaking, no spalling; .cracks devel- oped in first test not opening up. 3 hr., 30 min. no cracks over 0% in., brick flaking off at corners. 3 hr., 47 min. cracks are vertical and generally LOG OF FIRE TESTS 161 very fine, maximum & in. and not more than 2 ft. in length. 4 hr., 16 min. very little change, cracks open to J^-in. maximum; no fusion. 4 hr., 52 min. decided fusion in lower 3 ft. only. 5 hr., 20 min. maximum ex- pansion. 5 hr., 38 min. fusion extended up to 6 ft., fused brick run down to base at corners. 6 hr., 10 min. fusion up to 10 ft. above base. 6 hr., 27 min. fushion extends up to 11 ft. above base. No spalling, except sur- face flaking, occurred before failure. 6 hr. slight center deflection to west noted, increasing to % in. at 7 hr., 11 min. 7 hr., 13% min. failure with buckling to west, maximum at 5% ft. above base. After failure Fusion at bottom fluxed away about */ 2 in. of brick. Brick at bracket had just beg.un to fuse. (Figs. 76, 131 and 168.) (h) Reinforced Concrete Columns Test No. 70. Square Vertically Reinforced. Limestone Concrete 16 min. corners of column glowing slightly in lower 3 ft. 34 min. col- umn luminous entire length; slight flaking on corners near bottom. 1 hr., 11 min. fine vertical crack on east, 2 ft. to 3 ft. up. 1 hr., 28 min. similar crack 6 in. long, 1 ft. from base. 3 hr., 2 min. similar crack on east, 12 in. long near middle of column. 5 hr. maximum expansion. 6 hr., 39 min. fine vertical cracks with ends running horizontally to corners appeared on various faces. 7 hr., 50 min. cracks on east opening slightly; also a few additional fine cracks. 8 hr. column still supporting working load with no apparent change; no spalling. 8- hr., 1 min. load increased with fire going until failure occurred under 294,000 Ib. about 11 ft. above base, at 8 hr., 40% min. After failure. Concrete near outside calcined but had hard surface due to partial fusion of the sand in the concrete. (Figs. 76 and 132.) Test No. 71. Square Vertically Reinforced. Trap Concrete. 20 min. column glowing entire length. 2 hr,, 40 min. maximum ex- pansion. 3 hr. fine vertical cracks on east and west near bottom. 3 hr., 10 min. slight flaking at corners near middle. 4 hr., 10 min. the fine cracks on east and west faces extending in length. 4 hr., 40 min. several additional fine cracks on east and west faces, 4 in. to 24 in. long. Very little change before failure; no spalling. 5 hr. slight deflection to north noted, increasing to 54 m - at 7 hr., 22 min. 7 hr., 22^4 min. failure by compression about 5 ft. above base, reinforcing bars buckling outward. After failure. Concrete fused to average depth of 1 in. up to 7*/2 ft. above base; incipient fusion from 7^ ft. to 9 ft. up; no fusion above. Con- crete dry and loose in texture at top. Bar apparently straight except where buckled at point of failure. Concrete cracked at bars at some points but in general its condition at the corners was about the same as at the middle of the sides. (Figs. 77, 133 and 169.) Test No. 72. Round Vertically Reinforced. Limestone Concrete. 20 min. slight surface flaking. 1 hr. column glowing entire length. 5 hr. maximum expansion. 5 hr., 26 min. no spalling or cracking noted. 7 hr., 55 min. a few cracks noted on east and west faces & in. to Y& in. wide and 3 in. to 10 in. long as follows: on east at 3 ft. and 8 ft. up, on west at 2 ft. and 6 ft. up and at bracket. 8 hr. column still supporting working load with no apparent change; no spalling and but few cracks as noted; deflection less than ^ i n - 8 hr. 2 min. load increased with fire going until failure occurred under 250,000 Ib., about 6 ft. above base, at 8 hr., 4 l / 2 min., reinforcing rods buckling outward. After failure. Surface hard immediately after test due to partial fusion of sand. A few days after test concrete flaked off to depth of 1 in. due to calcination of limestone. (Figs. 77, 134 and 170.) Test No. 73. Round Vertically Reinforced. Trap Concrete. 19 min. piece of concrete about 8 in. wide and y 2 in. deep spalled on west 2 ft. above base. No cracking or other spalling noted before failure. Furnace gases very heavy making observation difficult; deflection not meas- ured. 4 hr., 10 min. maximum expansion. 7 hr., 57^ min. failure at 162 RESULTS OF FIRE TESTS 2 ft. to 4 ft. up, concrete crushing and shearing on inclined planes, reinforc- ing bars buckling outward. After failure. Concrete fused to depth of 1 in. at break, fusion being more decided in lower half than in upper half. Little or no concrete had run. A large number of fine vertical and horizontal cracks present more or less over whole surface of column. (Figs. 77 and 135.) Test No 74. Hooped Reinforced. Limestone Concrete. 40 min. no spalling or cracking noted. 53 min. two fine cracks 3 in. long, on west, $ l / 2 ft. up, opening to & in. wide and 10 in. long at 2 hr., 36 min. 5 hr., 50 min. maximum expansion. 6 hr., 50 min. several cracks % m - wide and about 8 in. long at 2y 2 ft. up and one crack $s in. wide and 8 in. long on east, S l / 2 ft. up; no cracks above. 8 hr. column still sup- porting working load with no apparent change; no spalling; deflection less than y% in. 8 hr., 5 min. load increased with fire going until failure oc- curred under 243,000 Ib. about 3 ft. above base, at 8 hr., &/ 2 min. After failure. Eight breaks in spiral reinforcement occurred near fail- ure point. Vertical bars buckled out 3 in. Concrete spalled outside of spiral 2 ft. to 4 ft. up. Otherwise no plane of cleavage at spiral. (Figs. 77, 136 and 171.) Test No. 75. Hooped Reinforced. Trap Concrete. Test. Gas shut off after 30 min. to repair burner and test post- poned till next day. Column apparently not affected. Second Test. 36 min. column glowing dull red for full length. 40 min. fine vertical crack, 4 in. long, on southeast 5 l / 2 ft. up, increasing to 12 in. long at 1 hr., 45 min. 1 hr to 2 hr. some six or eight fine cracks, 2 in. to 12 in. long noted in lower half. 2 hr., 20 min. all cracks opening slightly. 3 hr. many very fine cracks on all surfaces. 4 hr., 50 min. maxi- mum expansion. 6 hr., 25 min. cracks opened somewhat; observation difficult. 8 hr. column still supporting working load with little apparent change; no spalling. Deflection at 8 hr., less than ^ in. 8 hr., \ l / 2 min. load increased with fire going, failure occurring under load of 163,000 Ib. about 3 ft. above base at 8 hr., 1^4 min. After failure. Concrete fused to a depth of \ l / 2 in. up to IT ft. above base; concrete fluxed off to depth of 1 in., 7 ft. to 9 ft. above base. No fusion in upper \ l / 2 ft. due to excess of mortar near surface. Failure ap- parently due to yielding of spiral .although no break in it occurred. Ver- tical bars buckled out 1 in. at failure point. Concrete outside of spiral, shells off readily. (Figs. 77 and 137.) Note: For tests Nos. 76 and 77, see under par. (e) above, Hollow Clay Tile Protections, after Test No. 63. (i) Timber Columns Test No. 78. Longleaf Pine With Cast Iron Cap and Pintle. Protected by 1-in. Layer of Portland Cement Plaster on Metal Lath. 5 min. to 8 min. vertical cracks in lower half near northwest and southeast corners opening to ^ in. and 3 ft. to 5 ft. long. 9 min. vertical crack at northeast corner at bracket & in. wide, 12 in. long. 11 min. to 40 min. finish coat bulging out and spalling in lower half on north and south sides. 16 min. crack at bracket on west, y% in. by 8 in. 20 min. crack at pintle, northeast corner open % in. 44 min. ^-in. vertical crack near northeast corner \y 2 ft. to 6y 2 ft. up. 52 min. lath and supporting channel buckle out \y 2 in. on south side at west corner, 4 ft. up. 55 min. cracks at bracket on northwest corner open l /& in., on southwest corner J4 i n - 57 min. spurts of flame issue at southwest corner where lath buckled out. 58 min. crack at bracket on northeast corner open f in., on southeast open ^s in. 1 hr., 13 min. flames issue from cracks at bracket on west; flames free and full at southwest corner, 4 ft. up. 1 hr., 21 min. plaster spalled to lath, 8 in. by 12 in., on west, 2y 2 ft. up; flames issue at this point. 1 hr., 24 min. flames issue from crack at bracket on northeast corner. 1 hr., 57 min. head of column going down quite rapidly; column cap apparently level; crack noted in plaster at base of cap. 1 hr., 58 min. plaster spalled LOG OF FIRE TESTS 163 to lath, 12 in. by 12 in on east, 2 ft. up. 2 hr., 6 min. cap still level. 2 hr. f 8 min. little change in plaster during past 50 min. except as noted. . 2 hr., 9 min. small piece of plaster spalled on northwest corner, at lower part of bracket. Settlement of top of column due to heating of cap & in. at 1 hr., 10, min., % in. at 1 hr., 50 min., 1% in. at 2 hr. and 3 1 A in. at 2 hr., 15 min. (See Fig. 47). 2 hr., 15^4 mm. failure, due to cracking of cap. 2 hr., 17 min. water applied to column extinguishing flames at 2 hr., 21 min. After failure. Cap broken into three pieces by two transverse cracks across middle portion. A 2 in. by 2 in. by J$ in. chip broke off bottom edge of pintle on north. Beam ends charred to depth of 1 in. on sides and ends; inner surface surrounding pintle scarcely charred. Sides of column charred to depth of 1J4 in. in lower two thirds and to about 1 in. ^ towards top, minimum section of unburned wood, about 8 in. by 8 in.; vertical cracks on sides extend inward not over y 2 in. Top bearing surface of column not charred except for % in. at top edges but was crushed and frayed, the fibres being bent out over 3 in. beyond sound wood at the sides, and pushed up 2 in. to 3 in. into cracks in cap: A piece was sawed from southwest corner of top and fibers were found to have been crushed and turned over for a depth of 134 in. below surface. Wood crushed down on northwest corner 2 in. more than on south side of bearing surface due to pintle bearing on this side and transmitting the blow from ram at failure. Length of column below cap before test, 11 ft. 134 in.; average after test, 10 ft. 9 in., decrease in length 4?4 in. (Figs. 79, 140 and 47.) Test No. 79. Longleaf pine with cast iron cap and pintle. Unprotected. 2 min. surface of column blazing in lower 3 ft. 3 min. fine horizontal checks due to charring appeared. 9 min. column flaming all over. 11 min. three or four vertical cracks beginning to show near middle of each side, $r in. wide. 18 min. to 23 min. horizontal cracks showing in beam ends at top increasing to Y 2 in. at 32 min. 27 min. horizontal checks & in. wide and \y 2 in. apart quite general. 30 min. lazy reddish flames from combus- tion of wood envelop whole column. 32 min. vertical cracks in charred column generally 3/ in. wide. 42 min. head of column going down fast but no visible sign of distress. 44 min. vertical cracks $ in. wide; hori- zontal checks */4 in. wide. Settlement of head of column due to heating of cap iV in. at 25 min., \Y% in. at 40 min. and 3iV in. at 46 min. (See Fig. 47). 50 min. failure, due to cracking of cap. After failure. Cap broken into two pieces, cracking transversely at center. Pintle intact except for slight rounding of lower bearing surface. Beam ends charred to depth of iy 2 in. on sides and ends; inner surface sur- rounding pintle barely scorched. Sides of column charred to depth of 154 in.; minimum section of unburned wood 834 in. by 8% in. Vertical cracks on sides extend inward to a depth of 34 in. below sound wood. Column split in two in upper 3 ft. due to end of pintle being forced down through cap into top of column at failure. Top bearing surface very little charred but fibers crushed and broomed, forced outward 3 in. bevond sides, also down into crack in column and up into crack in cap. Fibers tough and ropy and bent over "for a length of 3 in. Length of column before test, 11 ft. 1 7/16 in.; average after test, 10 ft. 7 7/16 in.; decrease in length, 6 in. (Figs. 80, 140 and 47.) Test No. 80. Longleaf Pine With Steel Plate Cap and Timber Strut Bear- ing. Column and Cap Protected by One Thickness of ^-in. Gypsum Wall Board. 1 min. kalsomine burned off showing filler in joints and nailing. 5 min. paper on outer surface of wall board charring and flaking, about one half off at 7 min. 15 min. about two thirds of outer paper now off; no curling of wall board. 16 min. to 18 min. cracks noted near corners at bracket on east and west sides, up to ^ in. wide, extending and increasing to J4 in- on west at 26 min. 19 min. to 25 min. horizontal cracks developed on north, south and west faces from 1 ft. to 4 ft. up; wood burning freely 164 RESULTS OF FIRE TESTS at cracks, also a little along corners. 27 min. corner beading buckled out at several places, corners burning freely up to 7 ft. above base and to top at 40 miri. 31 min. cracks and free burning of wood on east face to 9y 2 ft. up. 32 min. about two-thirds of wall board on west side of cap fell, ex- posing steel. 35 min. board fell at cap on east exposing all of steel. 37 min. board in lower half buckled out at corners; horizontal cracks about 18 in. on centers on all sides with free burning of wood. 41 min. to 54 min. board fell off in places exposing wood; at end of this period wood was exposed on north at 4 ft. up, on east 2 ft. to 8 ft. up, and on south 2 ft. to 10 ft. up; board remaining in place, much shattered. 1 hr., 3 min. con- tinued cracking and falling of board; steel cap slanting slightly to north. 1 hr., 6 min. all board down on north 2 ft. to 4 ft. and 7 ft. to 8 ft. up; on west from 4 ft. up to top. 1 hr., 10 min. cap tilted, south edge dropped \ l /2 in. Settlement of top of column due to heating of cap & in. at 15 min., l / 2 in. at 40 min. and 27/% in. at 1 hr., 10 min. 1 hr., 13 min. failure by tilt- ing of cap, and slipping of same on top bearing strut, column and cap be- ing carried to north. After failure. Side plates of cap bent, also inner bolt on south side; bearing plate dished up 1 in. at middle. Strut did not slip and its upper bearing surface was uninjured; sides of strut charred to depth of l /2 in., lower bearing surface of strut charred about Y^ in. on edges, brown over rest of area. Fibers crushed and bent over \]/ 2 in. to 3 in. Strut cracked by longitudinal shearing. Sides of column charred to depth of 1 in. to 1^4 in.; minimum section of unburned wood, 9^ in. by 8-^4 in.; vertical cracks burnt in 24 m - to 1 m - deeper. Top bearing surface of column charred only at edges; surface convex, middle being about $i in. higher than edge; fibers crushed and bent over to south for depth of about Y 2 in.; bearing surface smooth and hard. Length before test, 12 ft. 2 in.; average after test. 12 ft. 1 in.; decrease in length, 1 in. (Figs. 81, 141 and 47.) Test No. 81. Longleaf Pine With Steel Plate Cap and Timber Strut' Bearing. Unprotected. 2 min. surface of column blazing, lower 3 ft. 6 min. column burning freely on south and west, lower half. 5 min. a few vertical cracks near middle. 8 min. column charred; irregular surface checks & in. wide, quite general. 16 min. several vertical cracks' ^ in. wide on all sides. 19 min. gases heavy making observation difficult. 32 min. color noted in cap. 34 min. all cracks about ^ in. wide. Settlement of top of column due to heating of cap -& in. at 20 min. increasing to it in. at 30 min., and It's in. at 34 min. 35 min. failure due to top of column sliding to south and west: fire kept burning until 43^ min. as it was not possible to ascertain definitely if failure had taken place owing to heavy smoke; column yielded quite gradually, only slight report heard at failure. 45 min. water applied to column extinguishing flames completely at 55 min. After failure. Upper part of side plates of cap bent forward toward the east; bearing plate dished up ^ in. at middle. Strut did not slip and its upper bearing surface was uninjured; lower bearing surface of strut charred to depth of % in. and fibers crushed and bent over to depth of */ 2 in. to 1 in.; strut split by longitudinal shearing. Sides of column charred to depth of 1-rV in.; minimum section of unburned wood 9 in. by 9 in. Top bearing surface of column charred not deeper than y% in. except at edges; fibers crushed and bent over to north for a depth of about y 2 in. Length before test, 12 ft. 2 in.; average after test, 12 ft. 1 1 4 in.; decrease in length, 7^ in. (Figs. 81, 141 and 47.) Test No. 82. Douglas Fir With Cast Iron Cap and Pintle. Unprotected. 3 min. surface of column blazing in lower 3 ft.; horizontal surface checks due to charring, \y 2 in. on centers. 10 min. column blazing freely all over; several vertical checks on all sides, < T^ in. wide, small pieces of charcoal falling. 14 min. horizontal checks & in. wide. 24 min. horizontal and vertical checks about ^ in wide. 25 min. column flaming all over but not so freely as pine columns at this stage. 36 min. pieces of charcoal falling off under cap indicating rapid dropping of head of column. 38 min. LOG OF FIRE TESTS 165 cap nearly level, no color. 41 min. buckling under cap more pronounced; noise heard at bearing. A2 l / 2 min. cap still nearly level. 44 min. wood fibers under cap appear to crush and buckle out. Settlement of top of col- umn due to heating of cap & in. at 15 min., 1 in. at 30 min., 3^in. at 41 min., and 5 J /& in. at 45 min. 45^4 min. failure due to cracking of cap. After failure. Cap broken transversely into two pieces. Small pieces chipped from outer edge of pintle on southwest at bottom; otherwise pintle uninjured. Beam ends charred on sides and ends to maximum depth of 1 in.; inner surface of wood surrounding pintle very slightly charred in places. Sides of column charred to depth of l^s in.; minimum section of unburned wood, 9J/2 in. by 9^ in.; vertical cracks did not extend into uncharred wood. Top bearing surface of column charred not more than % in. deep but was broomed and crushed, fibers bent out beyond sides of column, also pushed up 3 in. into crack in cap. A piece cut out of southwest corner showed fibers crushed and turned over 3 in to 3% in. below bearing surface; fibers tough, hardly scorched. Length before test, 11 ft, 1-M* in.; average after test, 10 ft. 6 in.; decrease in length, ?s/ 8 in. (Figs. 82, 140 and 47.) Test No. 83. Douglas Fir With Steel Plate Cap and Timber Strut Bearing. Unprotected. 2y 2 min. surface of column blazing lower half; top just beginning to burn. 2 min. to 4 min. crackling noises heard. 5 min. column blazing all over. 15 min. very little blazing, hardly any crackling, secondary air gate found shut; opened. 18 min. horizontal surface checks % in. wide, 1 in. on centers; 2 to 4 vertical cracks on each side not over ^ in. wide. 24 min. column again burning freely. 31 min. horizontal checks l /4 in. wide. 37 min. vertical cracks up to & in wide; very little crackling. 38 min. cap tilted, south edge dropped \ l / 2 in. Settlement of top of column due to heat- ing of cap T^ in. at 14 min., 1^ in. at 30 min., and 2 9/16 in. at 38 min. 38^ min. failure due top of column sliding to north carrying cap with it. 40^ min. water applied to column extinguishing flames completely at 45^ min. After failure. Side plates of cap bent outward at top, also inner bolt on north bent out; bearing plate dished up 1 in. at middle in longitudinal direction. Strut did not slip and its upper bearing surface was uninjured; lower bearing surface of strut charred to depth of ^ in. and fibers crushed and bent over to north maximum of 1 in. on north side. Sides of column charred to depth of 15/16 in.; minimum section of unburned wood 9 l / 2 in. by 9 l / 2 in.; top of bearing surface of column very little charred but discolor- ed to depth of 1 in.; surface convex, rounded over from Y 2 in. to 1 in. at edges; fibers crushed and bent over, mostly on east and west sides; wood quite soft to a depth of l /4 in. Length before test 11 ft. 2 in.; average after test, 11 ft. \y^ in.; decrease in length, % in. (Figs. 82, 141 and 47.) XL RESULTS OF FIRE AND WATER TESTS. 1. APPLIED LOADS, DURATION AND EFFECT OF FIRE AND WATER In the fire and water test, the column was subjected to working load, and to fire for a predetermined period not exceeding one hour, after which a hose stream was applied to three sides. On cooling, the column was either loaded to failure or subjected to an excess load equal -to about twice the load sustained during the fire and water periods. A general summary of applied loads, duration and relative in- tensity of fire exposure, duration and pressure of hose stream ap- plication, and the general effects of fire and water are given in Table 44. Further details of columns and protections are given in Tables 4a to 4f (p. 56-59). 2. PHOTOGRAPHIC RECORDS Views of the columns in the fire and water series at several stages of the test are given in Figs. 83 to 89, Appendix A (p. 256- 262). 3. FURNACE AND COLUMN TEMPERATURES The temperatures observed in the furnace and test column are given by the curves in Figs. 142 to 145, Appendix B (p. 317-320). The arrows on the plots indicate the time water was applied in each test. 4. LONGITUDINAL DEFORMATION The expansion of the column during the fire period and con- traction on application of water were determined by measurement of the movement of the head of the column and the amounts are given in the respective test logs. These effects were quite small except in the case of the unprotected cast iron columns, both of which attained maximum expansion before water was applied (Fig. 46, p. 138). 5. SUBSEQUENT LOADING TESTS The loading to which the columns were subjected subsequent to fire and water test are given in Table 44. They were loaded to their maximum sustaining capacity with the exception of four columns that were loaded to about twice their design working load and reserved for use in further tests, and the one protected by plaster on metal lath on which a subsequent fire test to failure under working load was made. 166 TABLE 44. RESULTS PROTECTION Load Sustained Test No. Section Thickness and Kind of Covering Materials and Details Age of Cover- ing, Days During Test, Lb. Dura- tion, Minutes Furnace Exposure Percent 101 Rolled H 2-in. 1 1:2:4 Chicago limestone concrete 515 119500 60 101.5 concrete 1:2:4 New York trap concrete 1:2:4 Joliet gravel concrete Wire tie wound spirally on 8-in. pitch 102 Rolled H 2-in. fl:2:4 New York trap concrete 518 119500 60 96.8 concrete 1:2:4 Joliet gravel concrete 1:2:4 Chicago limestone concrete No tie 103 Plate and 4-in. fl:2:4 New York trap concrete 518 116000 60 101.8 Angle concrete 1:2:4 Rockport granite concrete 1:2:4 Chicago limestone concrete Wire tie wound spirally on 8-in. pitch 104 Plate and 2-in. fl:2:5 cinder concrete 517 116000 60 100.3 Angle concrete 1:2-4 Cleveland sandstone concrete 1:2:4 New York trap concrete Wire tie wound spirally on 8-in. pitch 105 Plate and 2-in. tSurface clay, Boston district. New 541 116000 45 102.3 Angle hollow Jersey semi-fire clay. Ohio shale. clay tile No filling. Outside wire ties 106 Plate and Angle 2-in. hollow fOhio semi-fire clay. Surface clay, Chicago district. Ohio semi-fire 528 116000 45 108.2 clay tile clay. Concrete filling. Outside wire ties, upper half. %-in. wire mesh in horizontal joints, lower half. 107 Plate and 4-in. fOhio shale. New Jersey semi-fire 537 111000 45 103.2 Channel hollow clay. Surface clay, Boston district. clay tile No filling. Ties same as in No. 106 108 Rolled H 2-in. solid Western gypsum, upper half Eastern gypsum, lower half 507 119500 45 103.7 gypsum block 1:1:4 poured gypsum fill Wall ties in joints, upper half Wire mesh in joints, lower half 109 Rolled H 4-in. solid Eastern gypsum, upper half Western gypsum, lower half 507 119500 60 100.8 gypsum 1:1:4 poured gypsum fill Wire mesh in joints, upper half Wall ties in joints, lower half 110 Plate and Double Two 2-coat layers of Portland cement 500 116000 45 99.8 Angle layer plaster on metal lath, with %-in. air c 116000 c 167Ji c 99.5 plaster on space between layers metal lath 111 Square 2-in. fl:2:4 Chicago limestone concrete 520 101000 60 100.8 Verti- cally concrete 1:2:4 Meramec R. gravel concrete 1:2:4 Chicago limestone concrete Rein- Four 1-in. sq. vertical bars forced Concrete 112 Round Verti- 2-in. concrete fl:2:4 Chicago limestone concrete 1:2:4 Meramec R. gravel concrete 524 107500 60 95.6 cally Rein- 1:2:4 Joliet gravel concrete Six 1-in. sq. vertical bars forced Concrete 113 Hooped Rein- 2-in. concrete fl:2:4 New York trap concrete 1:2:4 Meramec R. gravel concrete 520 129000 60 100.0 forced Concrete 1:2:4 Rockport granite concrete Six ?^ -in. sq. vertical bars J^-in. hooping on 1%-in. pitch 114 Round Unpro- Vertically cast 98500 22^ 103.2 Cast tected Iron 115 Round Unpro- Vertically cast 98500 30 93.7 Cast tected Iron fThree kinds of concrete or tile used on each column placed in three vertical sections in the order named beginning at the top of the column. c Fire test to failure made subsequent to fire and water test. I) WATER TESTS WATER TEST LOAD TEST *Water Dura- Pres- * Excess Ultimate IfiSUltS tion, sure, Lb. Results Load, Load, Min. per Lb. Lb. Sq. In. teal cracks about 3 ft. ides in bottom section 5 50 Flange entirely exposed on S. in lower 3 ft. ; edges of flanges exposed in places on corners of W. face. Concrete 234000 Not applied generally pitted H to % in. on W. face; at 8 ft. up to depth of 1 in. jailing 5 50 N. QcjKge exposed for 10 ft. S. flange 442000 partly exposed, concrete being loose for 10 ft. Concrete washed off W. _ face to depth of M to 1M in. tcept small crack at 5 50 Concrete washed away on W. side in a537000 palling middle section \Y 2 to 3^ in. in upper and lower sections, y% in. at center, 3H in. on corners. Very little effect on N..S., and E. sides to 4 ft. long and M to fthree sides of center 5 50 W. side, concrete pitted ^ to 2 in. in upper and lower sections and ^ in. ia 234000 Not applied amount of spalling in center section. Steel bare on S. side, center section. Flange edges partly exposed on W. side in lower and center sections ered in lower 3 courses. VA 30 Steel exposed on three sides in lower b445009 naffected except for a section and in part of middle section. 1 cracks Tile nearly intact on upper half of column ailing of outer shells liddle section and in 2M 30 All tile washed off except in top and bottom courses and pome inner shells 228000 Not applied pper section on unexposed side. Fill remained in place ion cracked and a few VA 30 Almost all tile washed off in 3 upper b348000 ipalled. Middle and courses. Middle and lower sections at damaged except for little damaged n. wide general. Joints 3 30 % of covering carried down on W., N., bSHOOO & to y* in. and S. sides exposing flanges. Blocks remaining washed off to depth of ? in. to H in. wide general, joints open 1/32 in. 5 50 Gypsum washed away on three sides for a depth of 1 in., also mortar washed 234000 Not applied out of vertical joints on W. ff at bracket due to Bring VA 30 Outer layer of plaster washed off in a few places, mostly at top and at cor- Not applied c Not applied ghtly ners. A number of fine horizontal and vertical cracks appeared d diagonal cracks in 5 50 Concrete washed away to depth of 2 in. 379000 A to Y% in. wide. on W. face in middle section. Bars ncrete loose exposed nearly full length on W. side. Concrete washed away to ^ to 1 in. depth on parts of N. and S. sides 'king and crushing in 5 50 Concrete washed away to depth of 2 in. 423000 jome cracks extending exposing bars in middle and part of ower sections lower section on exposed sides. Con- crete pitted to 1 in. depth on upper section and spalling of outer 5 50 Nearly all concrete washed away out- 536000 in middle section side of spiral on exposed sides also on at several points. unexposed side in center section. Con- lical crack formed in crete pitted to inner line of wire lull red in lower half 1 30 No cracks in metal. Maximum deflec- 527000 tion l|Hi in. toward side exposed to water lull red all over 1 30 No cracks in metal. Maximum deflec- 502000 tion Y in. k toward side exposed to - water \ 'Pressure at base of playpipe. Water applied through a 1^-in. nozzle. Stream directed at west, north and south sides. a Column did not fail under load of 547,000 lb., capacity of machine. The concrete covering was then removed for a distance of 2 ft. 6 in. near the middle and load reapplied, the maximum sustained being 537,000 lb. b Covering completely removed before applying load. LOG OF FIRE AND WATER TESTS 167 6. LOG OF FIRE AND WATER TESTS (a) Concrete Protections Test No. 101. Rolled H. 2-in. Concrete Protection. Upper section, limestone; middle section, trap; lower section, Joliet gravel. Tied. Fire Test 30 min. no effect noted; flame very smoky. 32 min. vertical cracks on east and west faces near corners in lower 3 ft, y in. wide at bottom. 38 min. J^-in. vertical crack at center of south face, 2 ft. up. 45 min. cracks open & in. to % in.; small spall on southwest corner, 3 ft. up. 60 min. gas shut off; no change in column except cracks had opened up slightly. Water Test min. water applied to column through a Ij-i-in. nozzle; pressure at base of play pipe, 50 Ib. per sq. in.; nozzle was maintained at a distance of 20 ft. away from and to the west of column in all tests and the stream applied directly to the west face and at an angle to the north and south faces. Stream was played slowly up and down over all three faces of col- umn. 61^ min. pieces washed off southwest corner and west face, 3 ft. up. 61^4 min some pieces fell off west piece in upper section. 62J4 min. pieces falling on west face and corners in middle section. 63^4 min. concrete fell in lower 2 ft., exposing steel. 64y 2 min. north face washed off to depth oil l / 2 in., 1 ft. to 2*/ 2 ft. up, edge of flange exposed on northwest corner. 65^4 min. piece fell off north face near top. 66J4 min. water shut off; duration of water test, 5 min. After test. Edge of flange exposed on northwest corner 1 ft. to 2 l /2 ft. up, and southwest corner for 4 in. at 5 ft. and at 8 ft. up; these corners spalled not over l l / 2 in. by \ l / 2 in. for rest of length. Concrete in center of west face generally pitted from Va in. to % in for the whole length; at bot- tom of upper section concrete pitted to depth of 1 in. for about 6 in. On south face all concrete washed off in lower 3 ft. exposing flange; about two thirds of rest of surface pitted slightly. On north face surface generally smooth except at northwest corner. Fine vertical cracks in east face nearly ful length, \ l / 2 in. from corners. Column expanded 0.26 in. during the fire test and contracted 0.06 in. during the water test. Load Test On the following day the column was subjected to a load of 234,000 Ib this being calculated as the design dead load plus 2y 2 times the live load, as- suming the former to be one-third of the latter. A faint cracking sound was heard at 69,000 Ib. At about 175,000 Ib. a dull thud was heard and several small pieces of concrete fell off northwest corner about half way up. Col- umn withstood test satisfactorily. The column recovered from the depres- sion due to the loading within 0.002 in. on release of load. (Figs. 83 and 142.) Test No. 102. Rolled H. 2-in. Concrete Protection. Upper section, trap; middle section, Joliet gravel; lower section, lime- stone. No tie. Fire Test 21 -min. slight flaking at southeast corner, 9 ft. up. 41 min. column glowing all over. 60 min. gas shut off. No cracking or spalling. Water Test 62 J4 min. water applied to column; 50-lb. pressure. 62^4 min. cracks noted on west face near both corners; steam very heavy making observa- tion difficult. 64 min. concrete fell on north in lower 10 ft. exposing steel. 65 min. long vertical crack at southwest corner, exposing flange in places in lower 10 ft. 67*4 min. water shut off; duration of water test, 5 min. After test. North flange exposed completely \ l / 2 ft. to 11 ft. up. South flange exposed on southwest corner for 2y 2 in. by 14 in. at 2 l / 2 ft. up, for 4 in. by 20 in. at 5 ft. up, for 3 in. by 10 in. at 8 ft, for \y 2 in. by 12 in. at 10 ft. up. Concrete loose on south flange from 1 ft. to \\ l / 2 ft. up. On west concrete washed off to depth of y 2 in. to 1^ in. at 3 ft., 4J4 ft., 8* ft. and W l / 2 168 RESULTS OF FIRE AND WATER TESTS ft. above base. Concrete least washed off on middle section. Column ex- panded 0.26 in. during the fire test and contracted 0.09 in. during the water test. Load Test On the following day the column in the unstripped condition was loaded until failure occurred at 442,000 Ib. by buckling to west, about 8 ft. above base. Scaling on the surface of the steel was first noted on the north flange at 373,000 Ib., the yield point of the steel as determined from the depression curve of the top of the column, being attained at 400,000 Ib. (Figs. 83 and 142.) Test No 103. Plate and Angle. 4-in. Concrete Protection. Upper section, trap; middle section, granite: lower section, limestone. Tied. Fire Test 60 min. gas shut off; i^-in. vertical crack, 4 in. long, on west near southwest corner at bracket; no other cracking, spalling or other visible effects on column. Water Test 62 min. water applied to column; 50-lb. pfessure. 62^4 min. small pieces falling on west; face and corners rounded. 63^2 min. continued fail- ing of small pieces; steam heavy. 64*/2 min. water effects most marked at bottom of middle section. 6S l / 2 min. continued falling of small pieces. 67 min. water shut off; duration of water test, 5 min. After test. Little effect on north and south faces back of corners ex- cept in middle section where granite concrete was pitted to depth of % in. quite generally. On west face the middle section was most affected and the upper section least affected; concrete in middle section quite generally washed away to depth of \y 2 in. at center, and 3^2 in. at corners; in upper and lower sections, % in. to y 2 in. at center and 3^ in. at corners; concrete in middle section cracked along flanges near each corner; steel flanges not exposed. East face unaffected. -Column expanded 0.15 in. during the fire test. Load Test On the following day the column in the unstripped condition was loaded to 547,000 Ib., the capacity of the machine, without signs of distress or fail- ure. Column was then stripped from 5 ft., 2 in. to 7 ft., 10 in. above base and loaded until failure occurred at 537,000 Ib. by buckling to west, 7 ft. 8 in. above base. Scaling of steel was first noted at 433,000 Ib. and decided yielding began at 475,000 Ib. (Figs. 83 and 142.) Test No. 104. Plate and Angle. 2-in. concrete protection. Upper section, cinder; middle section, sandstone; lower section, trap. Tied. Fire Test 31 min. fine vertical crack, 24 in. long, on west near southwest corner, 6 l /2 ft. up; also on east, southeast corner, 4^ ft. to 7 ft. up; slight crushing on southeast corner 8 ft. up, small piece falling at 33 min. 35 min. %-in. crack on center of south face, 6 l / 2 ft. to 9y 2 ft. up extending to southwest corner at upper end. 50 min. cracks previously noted opening up % in. to Y 2 in. and extending in length in middle section. 53 min. piece spalled off northeast corner, 7 ft. up. 60 min. gas shut off; only cracks are the three noted in middle section, 3 ft. to 4 ft. long, and % in. to Y 2 in. wide; no cracks on north. Water Test 61^ min. water applied to column; 50-lb. pressure. 61^ min. con- crete fell off on south, 5 ft. to 8 ft. up, exposing steel. 63 min. concrete in lower 4 ft. on west washed and pitted considerably. 63^ min. concrete on northwest corner fell, 4 ft. to 7 ft. up. 67^4 min. upper 4 ft. on west pitted. 65 min. piece fell on northwest corner, 10 ft. up. 66 min. pieces washed off corners on west in lower 4 ft. 66^2 min. water shut off; duration of water test, 5 min. After test. West face pitted r / 2 in. to 2 in. in lower section, % in. in middle section and y 2 in. to 2 in. in upper section. Northwest corner off for LOG OF FIRE AND WATER TESTS 169 full length exposing flange edge for \y 2 in. by 12 in. at 2 ft. up, for 2 in. by 12 in., 4 ft. up and for \y 2 in., 5 ft. to 9 ft. up. North face intact except for spalling on northwest corner. Southwest corner spalled full length ex- posing flange edge for^ 3 in. by 4 in., 2 ft. up, and 2 in. by 6 in., 6 ft. up. Entire south flange exposed in middle section. East side intact except for a few fine cracks. Column expanded 0.26 in. during the fire test and con- tracted 0.09 in. during the water test. Load Test On the following day the column in the unstripped condition was sub- jected to an excess load of 234,000 Ib. without developing any signs of dis- tress and with full recovery from the deformation on removal of load. (Figs. 84 and 142.) (b) Hollow Clay Tile Protections Test No. 105. Plate and Angle. 2-in. hollow clay tile protection. Unfilled. Upper section, surface clay, Boston district; middle section, semi-fire clay, New Jersey district; lower section, Ohio shale. No filling. Outside wire ties. Fire Test 2 min. to 3 min. vertical cracks and spalling of parts of outer shells on north and west sides in lower section. 3 min. to 20 min. continued cracking, spalling and bulging of outer shells in lower section; tile in upper half very little affected. 30 min. a little more spalling in lower section; vertical cracks on west at bracket, and at south and west, 5 ft. up, % in. wide. ^ 39 min. outer shells spalled off on east and west, 3rd course, shell hanging loose on east, 2nd course. 45 min. gas shut off; very little damage to mid- dle and upper sections except for vertical cracks as noted; lower three courses cracked and spalled. Water Test 46 min. water applied to column; 30-lb. pressure. 46^ min. all tile washed off on west, 1 ft. to 2 ft. up, and on north, 1 ft. to 3 ft. up, exposing steel. 47 min. all tile down in lower section on north and west, 1ft. to 4 ft up. 47^/2 min. tile down on north and west 4 ft. to 5 ft. up. 48 min. tile still in place on south except outer shell, spalled, 3 ft. to 4 ft. up; tile down on west in center, 5 ft. to 6 ft. up. 48^ min. water shut off; dura- tion of water test, 2*/ 2 min. After test. Tile down and steel exposed on north and east 1 ft. to^ 5 ft. up and on west 1 ft. to 6 ft. up; tile loose on south, 1 ft. to 5 ft. up. Tile in upper half of column almost intact except outer shell cracked on west, 6 ft. to 7 ft. up, and part of outer shell off on north at bracket. Ties in lower 5 courses fell down, other ties in place. Expansion during fire test, 0.22 in.; contradiction during water test, 0.13 in. On the following day the column was stripped. Mortar in joints found to be fairly full, although in about one half of the joints it had been washed out to depth of */ 2 in. to H in. Mortar on flanges broke away from the steel and adhered to the tile. Lateral deflection less than % in. Load Test The stripped column was loaded until failure occurred at 445,000 Ib. with buckling to east about 6 ft. above base. (Figs. 84 and 143.) Test No. 106. Plate and Angle. 2-in. hollow clay tile protection. Upper and lower sections, Ohio semi-fire clay; middle section, surface clay, Chicago district. Outside wire ties on upper half of column; wire mesh in joints in lower half. Concrete filling. Fire Test 2^2 min, to 6 min. outer shells spalling at corners in middle section. 9 min. to 12 min. outer shells shattered on west in middle section but did not spall off; %-in. cracks near corners on west in upper section. 12^ min. to 18^ min. outer shells spalled and bulging in middle section; at end of this period, all of outer shells were down in 5th course on north and west, and partly down on east. 2Q l /a min. vertical crack in upper section on west 170 RESULTS OF FIRE AND WATER TESTS 9 l / 2 ft. to I\y 2 ft. up, f^ in., wide opening to 1 in. at 26 min. 23 min. outer shell buckled on east, 9 ft. up. 25^ min. tie wire broken on 10th course. 31 min. to 36 min. continued cracking and spalling of outer shells in middle section, also bulging out on north, 7 ft. up. 38 min. outer shell spalled on 6th course on north. 40 min. all outer shells spalled on. east, 3 ft. to 5 ft. up. 44 min. outer shells on east, 7 ft. up, buckle out 2 in. 45 min. gas shut off; outer shells are off on 5th, 8-th and 9th courses on west, and on 5th and 6th courses on north. Column expanded 0.24 in. during the fire test. Water Test A7y 2 min. water applied to column; 30-lb. pressure. 47^4 min. con- siderable amount of tile fallen; steam obscures view. 4S 1 A min. title down in middle 8 ft. on north, south and west exposing flanges on north and south; concrete filling in place. 49^4 min. water off; duration of water test, 2*4 min. After test. Steel exposed on north 1 ft. to 11 ft. up, on south from 1 ft. to 10 ft. up except where parts of inner shells remained in place; wire mesh still in place on north at 1 ft, 4 ft, 5 ft. and 6 ft. up. On west, tile off exposing concrete 2 ft. to 10 ft. up; outer shell off 10 ft. to 12 ft. up. On east side, concrete exposed 2 ft. to 4 ft. up; the rest was covered by tile or inner shells of same. Tile all in place on bottom, course on all sides and on bracket course on north, east and south sides. Load Test On the following day the column was subjected to an excess load of 228,000 Ib. without developing any signs of distress and recovered from de- formation almost completely on removal of load. (Figs. 85 and 143.) Test No. 107. Plate and Channel. 4-in. hollow clay tile protection. Upper section, Ohio shale; middle section, semi-fire clay, New Jersey dis- trict; lower section, surface clay, Boston district. Outside wire ties on upp'er half of column; wire mesh in joints in lower half. No filling. Fire Test 12 min. no cracking or spalling noted. 15 min. vertical cracks on east from 8 ft. up to top, ^4 in. wide; part of outer shell spalled on llth course, east; ife-in. vertical crack on east, 6 ft. to 8 ft. up. 19 min. -&-in. vertical crack on west, 6 ft. to 9 ft. up. 22 min. cracks on east and west near top, y 2 in. to 1 in. wide. 25 min. to 27 min. outer shells on west bulging out iy 2 in. to 2 in. in upper section, held by ties. 31 min. to 35 min. *4 in. vertical crack on west at south corner from 9 ft. up to top; other cracks opening up and outer shells bulging in upper section. 42 min. continued cracking in upper section; new crack on north 1 in. wide, llth course; tile on east llth and 12th courses cracked. 45 min. gas shut off; tile in upper section generally cracked and outer shells loose; lower section practically intact; middle courses have a few vertical cracks as noted. Water Test 46 min. water applied to column; 30-lb. pressure. 46^ min. little ef- fect; outer shell on west fractured in upper section. 46^4 min. little ap- parent change. 47^ min. outer shell down on west, 9 ft. to 11 ft. up. 48K min. tile almost all down on upper three courses. 48j^ min. water shut off; duration of water test, 2 l / 2 min. After test. All tile down in 10th and 12th courses- except on north side where tile is held by bracket; some mortar adheres to north and south flanges. Tile shattered on east and west, in 9th course. Tile in good condi- tion in lower 8 ft. except for a few %-in. vertical cracks on east and west, 6 ft. to 8 ft. up, and small hole in outer shell on west, 7ft. up. Mortar and mesh in joints in lower courses in good condition, it being necessary to wedge the tile apart in order to remove the covering. Column expanded 0.15 in. during the fire test and contracted 0.10 in. during the water test. Maximum deflection after fire and water test, 3/32 in. to west. Load Test On the following day the column was stripped and loaded to failure at 348,000 Ib., column buckling to west about 6 ft. above base. Decided yield- ing of the steel began at 322,000 Ibs. (Figs. 85 and 143.) LOG OF FIRE AND WATER TESTS 171 (c) Gypsum Block Protections Test No 108. Rolled H. 2-in. solid gypsum block protection. Upper half, Western gypsum; lower half, Eastern gypsum. Filled. Fire Test 13 min. fine "surface checks beginning to develop. 28 min. surface checks generally % in. wide and ft in. deep near lower end of column and very fine at top. 36 min. joints at bottom open & in. to J^ in. 43 min. very little change in fire effects. 45 min. gas shut off. Water Test 46 min. water applied to column; 30-lb. pressure. 47^4 min. little ef- fect noted except for surface erosion on west. 48 min. blocks fell on west, 2 ft., 10 in. to 5 ft., 8 in. up. 48% min. blocks down on west \ l /t ft. to 9 ft. up exposing flange edges and filling. 48^ min. blocks down on south, 4}4 ft. to 7 ft. up. 48<>4 min. blocks down exposing steel nearly full length on north and south. 49 min. water off; duration of water test, 3 min. After test. All blocks down on north \y 2 ft. to 9 ft. up, exposing steel; on south, from \ l / 2 ft. up to top of bracket, exposing steel except for a 2 ft. length above middle of column where mortar remained in place; on west, \ l /2 ft. to 4*4 ft., 6 ft. to 9 ft. and from 11 ft. to top. Filling washed out on west exposing web from 2 ft., 4 in. to 3 ft. up. All blocks in place on east except at places on corners. Blocks remaining on column on west washed off to a depth of 24 in., to point where fiber in blocks was charred. Mortar on flanges, and filling in web had evidently been quite full. Steel not rusted except where exposed by water. Column expanded 0.05 in. dur- ing the fire test and contracted 0.05 in. during the water test. Maximum la- teral deflection after fire and water tests, $5 in. Load Test On the following day the column was loaded to failure at 311,000 lb., column buckling to west about 7 ft. above base. (Figs. 86 and 143.) Test No. 109. Rolled H. 4-in. solid gypsum block protection. Upper section, Eastern gypsum; lower section, Western gypsum. Fire Test 16 min. a few corner cracks developed in lower half, 3s in. by 1 in. 22 min. fine surface checks beginning to develop near bottom. 42 min. sur- face checks quite general, forming in ^6-in. squares, checks 3*2 in.^ wide at bottom and ds in. wide at top; corner cracks opening ,to maximum of y% in.; vertical joints in lower half open & in.; slight spalling at corners. 53 min. to 57 min. surface checks open from ^ in. at base to 3*2 in. at top of column. 59^ min. gas shut off; surface checked all over, most at bot- tom; otherwise covering and column little affected. Water Test 60^4 min. water applied to column; 50-lb. pressure. 61^4 min. hose burst, water off. Gypsum washed off on west to depth of about 1 in., mortar in joints washed out from 1 in. to 4 in. depth, exposing ends of ties. Gypsum washed off on north and south sides, 1/4 in. to 1 in. depth. East side intact. 72^ min. water again applied; 50-lb. pressure. 73^ min. outer 1 in. of gypsum washed off clean on north and south. 74 min. almost all of mortar washed out of vertical joints on west. 76^4 min. i^-in. verti- cal crack on west near south corner, 9 ft. to 10 ft. up. 76^ min. water shut off; total duration of water test, 5 min. After test. On west side, surface washed very smooth, corners rounded; blocks slightly less than 3 in. thick; no mortar in vertical joints; ties all in place and hold mortar in horizontal joints. On north and south sides, faces of blocks rough, with fibers projecting; blocks about 3 in. thick; all joints generally full. East side little affected. No blocks loose. Edges of bracket and stiffner angles exposed. Column expanded 0.04 in. during the fire test. Less than 0.01 in. contraction during the water test. Load Test On the following day the column in the unstripped condition was sub- jected to an excess load of 234,000 lb., which it withstood without any signs of distress except for a few small vertical cracks in the blocks. (Figs. 86 and 143.) 172 RESULTS OF FIRE AND WATER TESTS (d) Plaster on Metal Lath Protection Test No. 110. Plate and Angle. Two layers of Portland cement plaster on metal lath with ^-in. air space between layer. Fire Test 6 min. furnace gases heavy, difficult to see column. 18 min. fire more luminous. 19 min. plaster cracked and spalled on all sides at bottom of bracket; this probably occurred at about 14 min.; corners spalled slightly on west. 32 min. fine crack on east, 2 in. long, 4 ft. up. 45 min. gas shut off; several fine cracks noted on all faces. Water Test 46% min. water applied to column; 30-lb. pressure. 46^4 min. vertical cracks near corners on all faces about 6 ft. long. 47% min. piece of plaster, 8 in. square, spalled off north face, 6 ft. up. 48 min. plaster washed off southwest corner in upper and lower 3 ft. 48^4 min. plaster washed off northwest corner, lower 4 ft. 49 J / 2 min. water off; duration of water test, 3% min. After test. On west side plaster off, 1 in. by 1 in., exposing lath on northwest corner 1 ft. to 4 ft up. Fine horizontal cracks across face at 4 ft., 6 ft., 7 ft., 7*/ 2 ft., 8 ft., 9 l / 2 ft., and 11 ft. up. On north side, lath exposed near west corner, 5 in. by 18 in., 6 ft. up. On south side, lath exposed on southwest corner, 1 in. by 2 in., from 7 ft. up to top; fine hori- zontal cracks across face at 5 ft. and 8 ft. up. On east side, vertical crack runs full length near south corner; fine horizontal cracks at 2 l / 2 ft., 4 ft. and 6 ft. up. Plaster cracked and lath exposed on all sides at bottom of bracket. Column expanded 0.14 in. during the fire test. No contraction during the water test. (See Fig. 46.) Subsequent Fire Test Since protection was little injured by the fire and water test, it was subjected to a second fire test to failure on the day following the fire and water test. 5 min. plaster bulging out 2 in. on north at bottom of bracket. 7 min. crack on west at southwest corner open l / 2 in., 7 ft. to 8 ft. up, extending further 4 ft. vertically at 11 min. 14 min. bulging of plaster on southeast below bracket. 39 min. plaster bulging away from lath in places on south- west corner fronj 7 ft. up to top. 46 min. northeast corner cracks opening up, &y 2 ft. to 11 ft. up. 1 hr. bulging of plaster increasing on all faces at bracket. 1 hr., 54 min. no change except all cracks opening up slightly. 2 hr., 25 min. about one half of lath exposed at bracket on west. 2 hr., 28 min. small areas of lath exposed at bracket on east. 2 hr., 47% min. failure with buckling to west, maximum at 7^ ft. above base. Column expanded maximum of 0.92 in. at 2 hr., 30 min. From this point to one minute before failure it compressed y 2 in. (Figs. 87, 144 and 46.) (e) Reinforced Concrete Columns Test No. 111. Square Vertically Reinforced Concrete. Upper section, limestone; middle section, Meramec River gravel; lower section, limestone. Fire Test 14 min. to 24 min. slight spalling of small pieces from corners in middle section. 26 min. to 31 min. cracking of concrete in middle section on all sides, cracks & in. to iV in. wide, and 12 in. to 30 in. long; cracking and crushing at southwest corner 6^ ft. up, cracks extending diagonally downward on both south and west faces. 36 min. upper and lower sec- tions apparently unaffected. 36^ min. crack on south 4*/ 2 ft. up, extending downward to 2 ft. above base. 37 min. cracks on southwest 6*/ 2 ft. up, now open ^ in. 46 min. same crack open \y 2 in., new crack extending upward 12 in. from same; crack on east, 5^ ft. up, open ^ in. 48 min. small vertical and diagonal cracks extending from crack at southeast corner 4H ft. to *5H ft. up. 53 min. -rV in. vertical and diagonal cracks near northwest corner on north and west 5 ft. up. 60 min. gas shut off; very little spalling; concrete at southwest corner in middle section, crushed. LOG OF FIRE AND WATER TESTS 173 Water Test 6\ l / 2 min. water applied to column; 50-lb. pressure. 63 min. steam heavy; observations impossible. 63% mm - concrete spalled to reinforcing ~od on northwest corner in lower half. 63^ min. west face washed off to ibout iy 2 -'m. depth. 64 min. northwest rod exposed to 10 ft. up. 64% min. southwest rod exposed to 11 ft. up. 65 min. concrete washed off in. middle of column on west exposing tie. 65% min. little change during past $4 nin. 66% min. water off; duration of water test, 5 min. After test. Concrete washed off both corners of west face 4 in. by 4 in. exposing reinforcing rods, 1 ft. to 11 ft. up. In center of west face concrete is washed off to average depth of 1 in. in upper section, 2 in. in niddle section exposing ties, and % in. in lower section. On north, ast and south faces, concrete in place in upper and lower sections except i west corners; in middle section, concrete washed off south face to depth f 1 in., 4% ft. to 5% ft. up, and off north face to death of y 2 in. in places om 4 ft. to 6 ft. up; east side unaffected by water but has several vertical acks in middle sections from the fire test. Estimated minimum area of oss section of concrete not spalled or loose in middle section, 187 sq. in., decrease of a little more than 25 percent of the original section. Column -panded 0.28 in. during the fire test and contracted 0.09 in. during the -iter test. Load Test On the following day the column was loaded to failure at 379,000 Ib. Column failed by diagonal shearing from a point 4% ft. up on southeast corner to a point 8% ft. up on northwest corner. No cracking or yield- ing was noted before the maximum load was applied. (Figs. 88 and 145.) Test No. 112. Round Vertically Reinforced Concrete. Upper section, limestone; middle section, Meramec River gravel; lower section, Joliet gravel. Fire Test 18 min. flaking on southeast corner, 6 ft. up. 23 min. to 25 min. flaking in middle section on south and east. 30 min. concrete crushed on south, 6 ft. to 7% ft. up, cracks opening to % in. at 32 min., loose pieces ready to fall. 31 min. vertical crack on southwest % in. wide, 4 ft. to 7% ft. up. 39 min. crack on south, 6 ft. to 7 ft. up, open ^ in. 43 min. several new cracks % in. wide and about 12 in. long in middle section. 51 min. to 57 min. spalling in middle section to depth of \ l / 2 in.; upper and lower sec- tions intact. 60 min. gas shut off. Water Test 61% min. water applied to column; 50-lb. pressure. 62% min. con- crete washed off exposing tie on west, middle section. 62% min. some concrete fell on south, middle section. 63% min. some concrete fell on south, 2 ft. to 5 ft. up. 64 min. reinforcing bars exposed on west in lower 7 ft. 64% min. piece fell on west, 7 ft. up. 66 min. piece fell on south, 8 ft. up; not much change during past 2 min. 66% min. water off; dura- tion of water test, 5 min. After test. Concrete off to reinforcing bars from 3 ft. to 8% ft. up on west and from 3 ft. to 8 ft. up on south; also piece off, 1 in. by 6 in. by 12 in., at 12 ft. up, and, 1 in. by 4 in. by 5 in., at 11 ft. up on west. On north concrete loose to outside of ties, 2 ft. to 6 ft. up and piece off, 1% in. by 12 in. by 6 in., at 6% ft. up. On east, crack y 2 in. wide from 6 ft. to 9% ft. up; concrete shattered near middle. Crack on northeast corner, % in. wide, 1% ft. to 4% ft. up. Several smaller horizontal and vertical cracks. Section at middle of column reduced about 30 percent due to spalled or loose concrete. Column expanded 0.14 in. during the fire test and contracted 0.02 in. during the water test. Load Test On the following day, the column was loaded to failure at 423,000 Ib. Failure occurred by diagonal shearing from 5 ft. up on north to 7 ft. up on south. Cracking sounds were heard at about 290,000 Ib. which increased as failure was approached. (Figs. 88 and 145) 174 RESULTS OF FIRE AND WATER TESTS Test No. 113. Hooped Reinforced Concrete. Upper section, trap; mid- dle section, Meramec River gravel; lower section granite. Fire Test 9 min. to 20 min. flaking, and cracking in middle section, cracks 54 in. maximum, 2 ft. to 3 ft. long. 21 min. piece ^ in. by 4 in. by 4 in. spalled on southwest, 5 ft. up. 22 min. crack on southwest in middle section open 24 in. 23 min. flaking and buckling of concrete shell general in middle section. 27 min. piece 1 in. by 4 in. by 10 in. spalled on southwest, 4*/ ft. up. 28 min. piece spalled, 1% in. by 10 in., on south 4 ft. to 7 ft. up. 34 min, buckling of concrete shell in middle section to 2 in. maximum. 37 min. upper and lower sections intact except for cracks extending from middle section. 38 min. spalling on south, 4 ft. to 8 ft. up; spiral exposed for 8 turns on 10 in. width. 43 min. concrete shell on west, middle section, standing out 2 in. 43^ min. spalling on east, 4 ft. to 8 ft. up; spiral exposed for 16 turns on 5 in. width. 46 min. cracks on west extending down to 1 ft. from base, are tf> in. wide at 3 ft. up, opening to \y 2 in. at 52 min. 58 min. cracks on east in middle section extending down to 3 ft. above base; finer cracks below. 60 min. gas shut off. Water Test 61 1 /4 min. water on; 50-lb. pressure. 6\ l / 2 min. hose burst; water shut off; concrete stripped to spiral on west from 1 ft. to S l / 2 ft. up and partly on north and south, 2 ft. to 6 ft. up; above this on north and south con- crete off to within 1 in. from spiral; aggregate split on plane of spiral. 79^ m in. water again applied; 80*4 min. pieces fell on west, exposing spiral at 6Y 2 ft. up. 80^4 min. pieces fell on west exposing spiral in upper section. 82 min. one-half of the circumference of the spiral exposed on west up to 9 ft. above base and one-fourth of its circumference exposed above this point; little change during past two minutes except concrete washed out between wires. 84J4 min. water shut off; total duration of water test, 5 After test. Concrete washed off to spiral all around in middle section, 4 ft. to 8 ft. up. In lower section, spiral exposed all around 1 ft. to 4 ft. up except for strip about 12 in. wide on east. In upper section, spiral exposed for about half of circumference on west, 8 ft. to 10^ ft. up, and for about one-fourth of circumference up to 12 ft. above base. Column expanded 0.14 in. during the fire test and contracted 0.045 in. during the water test. Load Test On the following day the column was loaded until failure occurred at 536,000 lb., 6y 2 ft. above base. All bars buckled put 1% in. and the spiral wire broke in tension with reduced section. Faint cracking sounds were first heard at about 300,000 lb. At 400,000 lb. the compressive deformation iue to a given load increment was about twice that at the start, and 500,- 000 lb., about five times the initial rate. (Figs. 89 and 145.) (f) Unprotected Cast Iron Columns Test No. 114. Round Cast Iron. Vertically cast. Unprotected. Fire Test 22y 2 min. gas shut off; column glowing low red in lower half; no vis- ible deflection. Water Test 23 min. water applied to column; 30 lb. pressure. 23^4 rnin. column still glowing on north, east and south. 23^4 min. still glowing on east. 24 min. water off; duration of water test 1 min.; column still glowing in lower third on east. After test Column unaffected as far as could be seen except for deflec- tion of 1^ in. to west, 4 ft. above base. Column expanded 0.99 in. during the fire test and contracted 0.51 in. during the water test. (See Fig. 46). Load Test On the following day the column was loaded to failure and supported a maximum load of 527,000 lb. Pumping was continued but load fell off grad- LOG OF FIRE AND WATER TESTS 175 ually until at 428,000 Ib. column broke in two with great violence, 6 ft. above base. During the loading the column deflected % in. to west at center at 445,000 Ib., and y 2 in. at 520,000 Ib. Fracture coarse gray, crystalline- break very jagged. (Figs. 89, 146 and 46.) Test No. 115. Round Cast Iron. Vertically cast. Unprotected. Fire Test 20 min. trace of color visible on column. 30 min. gas shut off; column glowing low red entire length; no visible deflection. Water Test 31^4 min. water applied to column; 30 Ib. pressure. 3l l /> min. column still glowing on north, east and south. 31^4 min. still glowing on east. 32 min. still glowing in lower half on east. 32% min. water off; duration of water test, 1 min.; no color on column. After test. Column unaffected as far as could be seen except for de- flection of % in. to west 5*/> ft. above base. Column expanded % in. during the fire test and contracted f in. during the water test. (See Fig. 45.) Load Test On the following day the column was loaded and supported a maximum load of 502,000 Ib. Pumping was continued with load decreasing until at 348,000 Ib. it was removed to avoid breaking the column. During the test, column deflected $ in. to east at center at 290,000 Ib. when deflection changed direction. At 450,000 Ib. it was MJ in. east increasing rapidly to the west until at maximum load it was \y 2 in. west. Deflection continued to increase until load was removed when column recovered a large part of the deflec- tion. (Figs. 89, 145 and 46.) XII. GENERAL SUMMARY AND DISCUSSION Included under this head are considerations relative to the quality of the materials of the test columns and their coverings; the general effects of load, fire and water; the useful limit of the various types of columns as loaded and exposed to fire ; test dura- tions, effects of methods of application and causes of variation in results. 1. CHARACTERISTICS OF COLUMNS AND THEIR MATERIALS These relate to the structural quality of the test columns and the physical and thermal effects of load and fire. (a) Structural Steel Columns (1) Material and Fabrication. The < structural steel for the test columns was made by the open-hearth process in four mills in different localities and in point of chemical and mechanical proper- ties came fairly within accepted specification limits. Measurements of area of structural sections indicated general agreement with the nominal or handbook areas within one percent, although a few measured areas differed from the nominal by amounts up to 4 per- cent. The columns were detailed according to standards of current practice, and as furnished fabricated by five companies, no defects due to faulty design or fabrication were noted before test or de- veloped as a result of the tests, except that the bearings as received were too uneven to insure uniform distribution of load (p. 19). A number of structural steel columns that had been subjected to "fire and water tests in the protected condition without injury to the steel, were subsequently stripped of their covering and loaded to failure, the maximum loads sustained being 30,600 to 37,600 Ib. per sq. in., which represent ultimate factors of safety from a little less than 3 to over 4 on the computed working loads. (2) Effect of Slenderness Ratio. The slenderness ratio / \ 1 r \ within the limits 40 to 80 appears to have little influence on the strength of structural steel building columns as exposed to fire. In the case of some of the columns of higher slenderness ratio, deflections were larger at a given stage of the test than for columns 176 * CHARACTERISTICS OF COLUMNS AND THEIR MATERIAL 177 of more rigid section. The columns had flat end bearings, the upper end being fully restrained and the lower end partly restrained by the base angles and anchor bolts (p. 88). (3) Lateral Deflection. The direction of the lateral deflec- tion before and after failure conformed with the line of least rigidity of the section, except in a few cases where the direction of the deflection was influenced by local heating of portions of the column. Deflections immediately before failure of a little over two inches were noted in a few tests, although generally they were between \y 2 and 2 in. Decided lateral deflection did not as a rule develop until the point of maximum expansion had been passed. (4) Vertical Deformation. Steel columns when loaded and exposed to fire expand up to a point where the rate of compression of the metal due to the load becomes equal to or greater than the thermal expansion. The total expansion varied from % in. for the columns nearly uniformly heated over the 12 ft. exposed length, to Y% in. for those subjected to local heating due to failure of portions of the covering. The measured expansion per unit length up to the point of maximum expansion, as measured over a 37-in. gauge length, varied from 0.0044 to 0.0066, the lower values being due mainly to local heating. The unit expansion per degree C. rise of temperature, or coefficient of expansion of the columns as loaded and exposed to fire, averaged 0.0000125 (0.000007 per degree F.) as taken from room temperature up to the point where decided yielding of the metal was apparent. (5) Load Carried by the Covering. On application of work- ing, load, the covering takes portions of the load proportionate to its area and rigidity with reference to the steel. With increase of temperature the higher rate of expansion of the steel causes a larger portion of the load to be transferred to the steel section, this condition continuing up to the point of maximum expansion. Sub- sequently, the compressive yielding of the steel causes load to be again transferred to the covering, the amount depending on the stability and load carrying capacity retained by the covering mate- rials after the fire exposure. (6) Average Effective Temperatures. For the steel columns for which average effective temperature determinations were made (Table 43, p. 136-137), the range at maximum expansion was from 484 to 593 C. (903 to 1099 F.) with an average of 530 C. (986 178 GENERAL SUMMARY AND DISCUSSION F.). At failure the average temperature range was from 570 to 837 C. (1058 to 1539 F.), the average of all determinations being 668 C. (1234 F.). The applied working loads if carried by the steel alone correspond to stresses of 8,900 to 14,500 Ib. per sq. in., as vary- ing for the different structural sections, the average being 11,600 Ib. per sq. in. (Table 41, p. 110). . The lower temperatures given above correspond nearly with those that hold for steel at maximum expansion and at failure under the given unit loads. The higher temperatures obtained in the tests where the covering carried portions of the load, this effect being much less marked at maximum expansion than at failure. (7) General Cause of Failure. The failure in the fire test was due in all cases to decrease in mechanical strength of steel with increase of temperature. The temperature required to cause failure depended mainly on the unit load carried by the structural section, although uneven stress distribution as caused by incidental eccentricity of load application, uneven bearings and deflection of the column, entered as possible modifying conditions. The general or local lateral deflections occurring immediately before failure were due to yielding of the metal and can be considered as failure effects. The deflection and distortion at failure caused large perma- nent loss of load carrying capacity, depending on the amount of the deflection and the rigidity of the section, the remaining strength being estimated at 5 to 50 percent of that before test. (b) Cast Iron Columns (1) Material and Manufacture. Of the ten cast iron columns tested, seven were cast horizontally and three were cast in vertical position. The iron of the horizontally cast columns conformed with published specifications for gray-iron castings in point of chemical and physical properties, the specimens being cut from the ribs in the head section of the columns. The tests made on the iron of the vertically cast columns were too few to be conclusive but they indicated difference in the strength of the iron of 15 to 20 per cent a's between the two ends of the column (Table 9, p. 354). The wall thickness of the columns differed from the nominal thickness by a maximum of J4 m - f r the horizontally cast columns and A in. for the vertically cast pipe columns, the difference being caused mainly by displacements of the molding core in casting the columns. CHARACTERISTICS OF COLUMNS AND THEIR MATERIALS 179 Two of the vertically cast columns that had been subjected to fire and water tests which induced permanent lateral deflections in one of % in. and in the other of 1J6 in., were subsequently loaded to failure, the maximum sustained being 36,400 and 34,700 Ib. per sq. in., respectively. (2) Deformation and Temperature. The same general char- acteristics of deformation and temperature obtained for the cast iron as for the steel columns. The average unit expansion at- tained by the cast iron columns was 0.0064 against 0.0054 for the steel columns, the average temperature at maximum expansion and at failure being about 70 C. (126 F.) higher than as obtained with the steel columns, the difference being due to the lower allowable working loads applied to the cast iron. The average applied unit loads, if assumed carried by the metal section alone was 6500 Ib. per sq. in. as compared with 11,600 Ib. per sq. in. average for the steel columns, a difference that was considerably reduced by the interaction of the coverings, which were heavier around the steel columns and generally carried larger proportions of the applied loads than those of the cast iron columns. (3) Cause and Character of Failure. Failure in the fire test was primarily due to inability of the metal to sustain load at the given temperature, the buckling and fracture incident with failure being in the nature of failure effects. The partial or full fracture of the metal section at one or more points, resulted in almost com- plete loss of load sustaining capacity. The direction of the de- flection for the columns having uneven wall thickness was quite uniformly toward the side with the heavier thickness, due evidently to compressive yielding of the thinner and more highly stressed metal on the opposite side. (c) Pipe Columns (1) Material and Manufacture. No tests of the metal of the pipes were obtained but the material was apparently mild steel with yield point between 27,000 and 33,000 Ib. per sq. in. The metal was of standard thickness. Cylinders taken of the l:lj^:3: concrete mixed for the filling of the plain pipe column developed an average compressive strength of very nearly 4000 Ib. per sq. in. at the time the column was tested. The columns were filled at the manufacturer's plant and fur- nished 'complete with bearing details, the latter being arranged to approximate conditions of use in buildings (Fig. 7, p. 28). 180 GENERAL SUMMARY AND DISCUSSION (2) Deformation and Temperature. The metal being ex- posed, attained early in the fire test a higher temperature than the filling, and expanding away from the latter, would assume most of the applied load, the unit stress, if all of the load was carried by the pipe metal, being 16,500 Ib. per sq. in. for the plain concrete- filled pipe column. The point of maximum expansion was in this case well defined and was attained at an earlier period and lower temperature than in tests of steel and cast iron columns of about the same duration, due to the higher load sustained by the metal. The compressive deformation subsequent to maximum expansion was large and developed the strength of the concrete filling before fail- ure occurred. The reinforced pipe column which had structural angles em- bedded in the concrete filling, expanded only a small amount dur- ing the fire test, yielding of the pipe metal under the high induced stresses beginning early in the test. Toward the end of the test the temperature of the pipe was so high that it could have sustained only a small part of the load, which must have been carried mainly by the steel reinforcement with stresses too high to permit much expansion. Lateral deflections began at about the time the pipe metal be- gan to yield and increased as failure was approached. (d) Reinforced Concrete Columns (1) Mechanical Properties of the Concrete. Made under conditions approximating those obtaining in building construction, the concrete developed wide variability in strength and elastic properties, the principal cause of which was difference in water content of the concrete mixture. The average compressive strength of 8 by 16-in. cylinders of 1 :2 :4 limestone and of trap rock con- crete made from the concrete mixed for the reinforced columns was 1525 Ib. per sq. in. at 28 days and 1930 Ib. per sq. in. at 16 months, with maximum variations above and below the averages of 67 and 54 percent, respectively. The modulus of elasticity at 650 Ib. per sq. in. had an average value of 3,080,000 Ib. per sq. in. with concrete aged 16 months, its variability being somewhat greater than that of the compressive strength. This variability in strength and elastic properties appears to have had little influence on the fire resistance of the concrete. CHARACTERISTICS OF COLUMNS AND THEIR MATERIALS 181 (2) Deformation and Temperature. Maximum unit expan- sion of 0.0023 to 0.0046 were observed in fire tests of reinforced concrete columns, the average being about one-half of that found ' for cast iron columns. The indications are that a considerable por- tion of the expansion was due to the vertical steel reinforcement, maximum expansion being coincident with temperatures in the reinforcement of 400 to 500 C, in which region yielding of the metal takes place under stresses that were likely to be induced in the bars by their higher expansion rate with reference to the con- crete. With limestone or trap rock concrete and with lateral ties not less than 12 inches apart, no tendency for the vertical bars to buckle before failure was noted. Following maximum expansion, the columns gradually com- pressed, the rate being less rapid than for steel and cast iron columns (Figs. 169 to 171). Temperatures at failure in the center of the trap rock concrete columns that failed in the fire test aver- aged 450 C. (842 F.) and in the vertical reinforcing bars, 894 C. (3) Character of Failure. The columns failed locally by com- pression or by combined compression and shearing on inclined planes, the vertical bars buckling and lateral ties or hooping, break- ing or yielding at the point of failure. No large lateral deflections developed either before or at failure. (e) Timber Columns (1) Quality of Material. The timber was longleaf pine and Douglas fir of select structural grade, and conformed with the re- quirements of published specifications for structural timber (Table 2, p. 34). (2) Deformation and Temperature. Except for slight expan- sions noted during the first few minutes of the test, the timber con- tracted or compressed under the combined load and fire condition, most of the deformation occurring in the wood at its bearings on the metal cap introduced near the top of the column, the crushing of the wood at these points causing progressive depression of the top of the timber columns (Fig. 47, p. 140). The temperature in the timber away from the surface and the cap bearings was retarded by the evaporation of moisture and the low heat conductivity of the wood, and did not exceed 100 C. (212 F.) until near failure (Figs. 140 and 141). In the metal cap at the edge of the column bearing, the temperatures at failure varied for the different tests from 432 to 544 C. (810 to 1011 F.) (Table 43, p. 136). 182 GENERAL SUMMARY AND DISCUSSION (3) Cause of Failure. The cause of failure of the timber columns was loss of strength of the wood at the cap bearings, due to conduction of heat from the flanges of the metal caps to the bear- ing plates and into the wood. The consequent softening of the wood caused the columns to slip laterally on their bearings with the steel plate caps and to fracture the cast iron caps. While the test fire reduced the area of the columns by 29 to 55 percent, their resistance to fire and load outside of the bearings was not fully developed in the tests. 2. USEFUL LIMITS The useful limit point with reference to fire exposure of columns is here taken as the limit of the period within which the effects on the elements designed to carry load do not permanently impair their essential structural properties to such extent as to make them unsuitable for further use. (a) Structural Steel and Cast Iron Columns The test characteristics indicate that for columns restrained at the ends and with slenderness ratio not exceeding 80, the useful limit is approximately equal to the period of expansion as given in Table 43 (p. 136) and Fig. 45 (p. 134). The measured center deflec- tions of columns within the given limit did not exceed one-half inch at the end -of the expansion period. The deflection of some of the col- umns of higher slenderness ratio was larger, although at the given stage all measured deflections were within one inch. Since failure in details such as riveting was not apparent in any test, unfavorable conditions in this respect could not have existed at any time preced- ing failure. Recent tests made by the Bureau of Standards on specimens of structural shapes that were heated under load up to the point of maximum expansion and cooled, indicate little or no distortion of shape, loss in strength or change in elastic properties. The compressive set on cooling and removal of load was not large enough to be objectionable as applied to a building column. In case of the structural steel columns with 2-in. Chicago lime- stone or Joliet gravel concrete coverings, the interval between maximum expansion and failure was equal to 73 percent or more of the expansion period, and considering the consequent lower rate of deformation of the column, the useful limit may possibly extend USEFUL LIMITS 183 considerably beyond the expansion period. The same applies to the columns with 4-in. concrete coverings made with the Chicago limestone aggregate, which withstood the fire test in excess of eight hours. Damage to the covering is not considered in the above dis- cussion as it is commonly not regarded as a load-carrying element. (b) Pipe Columns For the unreinforced- pipe column the useful limit can be taken as the period of expansion in the fire test. For the reinforced pipe column, the transfer of load, as caused by successive heating and expansion, first to the pipe and later to the structural steel reinforcement, confounds the relation existing between maximum expansion and useful limit. The temperatures on the outside of the pipe indicate that the useful limit was reached after between 20 and 30 min. of fire exposure. The center lateral deflection at the end of this interval was 4 i n - (c) Reinforced Concrete Columns The reinforced concrete columns expanded less than the steel and cast iron columns, reached their point of maximum expansion at a relatively earlier stage, and the subsequent compressive de- formations and center deflections were smaller. Comparisons of the temperatures of the reinforcing bars and the attending unit deformation indicate the presence of high compressive stresses, al- though with concrete of the given aggregates and the methods of tying employed, no tendency to buckle before failure was noted. For the columns that withstood the 8-hr, fire test and sustained large additional loads before failure, it is believed that the useful limit extended up to the end of the fire test. In the case of the columns that failed in the fire test or sustained but small additional load after 8 hr., the matter is more indeterminate, although it can be stated that large compressive deformations did not obtain until within the \y 2 hours preceding failure. These considerations do not preclude damage to the outer con- crete covering which it might be necessary to repair or replace after fire exposures within the useful limit. (d) Timber Columns The effect that limits the usefulness of timber columns after fire exposure, as far as it concerns the timber, is surface damage 184 GENERAL SUMMARY AND DISCUSSION from burning away of the wood with consequent reduction of effec- tive section. Large compressive deformation of the column due to impairment of the unburned wood from the heat, apparently ob- tains only for points nearer failure. The amount of reduction in area that can be allowed depends on the basis of design. In com- mon with general practice, the whole area of the test columns was assumed to carry load, no portion being deducted as protection. Assuming that the initial factor of safety was no more than ade- quate, minor reductions in area would render the column unfit for further use. Practical requirements relative to minimum and standard sizes often result in loadings lower than the safe working limit, in which case proportionate reductions in area due to fire could take place without impairing the safe load carrying capacity. With reference to fire effects on unprotected steel and cast iron bearings, the rapid rates of deformation obtaining after 20 min. in tests of 'unprotected timber columns indicate that the useful limit in this particular did not extend much beyond this period (Fig. 47, p. 140). For the protected timber columns the useful limit in this respect extended to within about the same time interval (15 to 30 min.) before failure as in the tests of unprotected timber columns. (e) Practical Application The above conclusions relative to useful limits find appli- cation where it is desired to design and protect columns so they will not be materially injured by a fire that consumes the contents of the structure supported by them. In applying the results of these tests for this purpose it is necessary to make deduction for variations in material and workmanship not developed in the tests. The percentage reduction can be safely taken at that used in de- ducing ultimate fire resistance periods in the concluding section of this report. The period of expansion is influenced to less extent by incidental conditions, such as load carrying capacity of covering materials than is the time to failure. While the useful limit may be made the basis of design of columns and coverings in special cases, it is believed that the most general use of the test results will be that based on the ulti- mate fire resisting point, hence no detailed application of the former will here be made. DISCUSSION OF TEST DATA 185 3. DISCUSSION OF TEST DATA The considerations herewith given relate to test duration, period of expansion, and the causes immediately affecting them. Comparisons of the time to failure of columns in the fire test series arranged by groups are given in Fig. 48 (p. 186) which also pro- vides a measure of the variation obtaining within each group. Fur- ther comparisons of time to failure and period of expansion are given in Table 43 (p. 136) and Figs. 42 (p. 129) and 45 (p. 134). In the discussion, the time periods will be given to the nearest minute. (a) Difference in Columns, Test Exposure and Service Conditions (1) Variations Due to Difference in Columns. Among the effects tending to produce variation in results with given types of protection for the same thickness of covering are, size and shape of structural section and consequent differences in intensity of load- ing and resistance to fire; differences in fire resisting properties of sub-classes of covering material within each group, such as concrete of the different aggregate combinations and hollow clay tile of the various types of clay; variations in methods and details of ap- plication; incidental variations in material and workmanship. These are discussed in connection with each group whenever the test results developed information on any given particular. A fairly wide range of structural section was employed in the tests and it is believed that the influence of this factor was suffi- ciently determined. One or more representative materials from, each of the main sub- classes of covering material were introduced. It is appreciated that considerable differences in mineral composition and structure may exist between material in a given sub-class as occurring in different localities, and while the difference in fire resisting proper- ties may be of minor order, wide application of the results of the tests will have to be made with care until the knowledge on the subject has been extended by further tests. The full range in results due to difference in methods of ap- plication and in incidental variations in materials and workmanship was not developed in the tests, as this required a greater number of test duplications than could be introduced. In general, poured coverings are subject to smaller incidental differences than those built up from small units, also if stability is assured, a large element of variability is eliminated. It is also thought probable that columns and protections in buildings are subject to greater varia- bility than those constructed for the tests, the latter representing workmanship of more uniform quality. 186 GENERAL SUMMARY AND DISCUSSION : 2 - 1 Ti ."= .-C soi e =m JEffl - DISCUSSION OF TEST DATA 187 (2) Variations Due to Difference in Load and Fire Conditions. In the tests, the amount of load applied to a given column sec- tion or column type was subject to minor variations only, the errors being generally within one per cent. Comparisons of the initial deformations produced in opposite flanges of individual columns indicate maximum outer fiber stresses in several tests up to 25 per- cent above what would obtain for uniform distribution of load. These can be ascribed mainly to bending stresses induced by un- even bearings and are no larger than those generally incident with compression tests or with normal loading of columns in buildings. The loads applied in the tests were about 10 per cent higher than those derived from the column formulas employed (p. 110). While floors in buildings are subject to overload by more than this amount, the resultant load on the columns is likely to be reduced by the distribution of load concentrations to several columns and by the equalizing effect of loadings from several stories. As exposed to fire in buildings, individual columns may take added load due to higher temperature and consequent greater ex- pansion than the adjacent columns of the story, particularly if they are not fully protected. For steel or cast iron columns the addi- tional load assumed is limited by the ultimate flexural strength of their connections to the floor beams framing into them. In the case of interior columns the additional load possible to assume on this basis will seldom exceed 20 percent of the nominal floor loads Reinforced concrete columns have more rigid floor connections than steel or cast iron columns, but due to their lower expansion and rate of temperature rise, more unfavorable loading conditions as due to unequal expansion, are not likely to occur. The furnace exposures are given in the test results as per- centages of the average of all tests, the quantity compared being the area under the average time-temperature curve of each test. For the shorter tests with upper limit of duration of about one hour, the difference in exposure may have had a considerable influence on results, considering also that the percentages given do not indi- cate the full measure 'of the difference due to lag of the pyrometers. For the longer tests, variations in test results due to difference in furnace exposure were apparently of minor importance. 188 GENERAL SUMMARY AND DISCUSSION ' Comparing the average time-temperature curve of the column tests with the reference curve (Fig. 39) a fair agreement is seen to have been 'attained. The reference curve was adopted as being con- sistent with furnace exposures used in previous fire tests and there was at the time no distinct understanding whether it should repre- sent indicated temperatures or temperatures corrected for lag and radiation effects, little information on the extent of these effects being available. Investigations conducted subsequent to the com- pletion of the column tests disclosed large effects due to lag during the initial period of the fire exposure and smaller but more per- sistent effects due to radiation (p. 115-120, Figs. 40 and 41). Any time temperature relation adopted as standard is necessarily more or less arbitrary, particularly for the initial period. Tempera- tures attained in fires afford some guidance although they indi- cate a wide range in intensity. From the information available, points on the reference curve, considered either as indicated or as corrected temperatures, while not the maximum attained in fires of exceptional intensity, represent severe fire conditions. (b) Unprotected Columns Included under this head are structural steel, cast iron and pipe columns that were tested without protective coverings, all parts of their sections being assumed to carry proportionate portions of the applied load. (1) Structural Steel. The time to failure of the unprotected steel columns varied from 11 to 21 min. (Table 42a, p. 123). The difference in results for the various column types, while due in part to variation in furnace exposure is attributable also to difference in thickness of metal and in the unit loads sustained, sections with thin members under the higher unit loads failing sooner than sections whose members were arranged to form heavy metal thickness. Fig. 49 is a plot between unit load sustained and time to failure in tests of unprotected structural steel columns, showing the inverse relation obtaining between them. The varia- tion in the unit load applied was due to difference in slenderness ratio between the different sections. v DISCUSSION OF TEST DATA 189 IT w S^ 1 , 7 L 0) a 13000 \ V. 2? I2OOO 3 6 1- cn c 1 1 OOO ol ,5 ^ \ i_ 3 Q IOOOO ??> \ a a c >x \ 8 5 00 ROOD 5 \ a re 1 1 1 2 1 1 3 1 "ime 1 4 1 to Fa 5 1 lurp 6 1 in M 7 .1 nute. 8 1 i 9 O 2 i e Fig. 49. Effect of load on fire resistance, unprotected structural steel columns The average time to failure of the eight structural steel sec- tions was 15 min. and the average period of expansion was 13 min. (Table 43). Maximum temperatures from 578 to 668 C. (1072 to 1234 F.) were attained on the outside of the metal near the edges. It is difficult to estimate the average effective temperature since the rise was too rapid to permit assuming temperature uniformity over the thickness of the metal. Tests recently made by the Bureau of Standards on small specimens indicate that for the loads sus- tained by the unprotected columns the failure temperatures of the structural steel fell within the limits 550 to 650 C. (1022 to 1202 F.). (2) Cast Iron. The average time to failure of the unprotected and unfilled cast iron columns, one of which was tested with ends restrained and two with unrestrained ends, was 34 min., the vari- ation being less than one minute for the three tests. The periods of expansion varied from 22 to 24 min. The longer test periods and higher temperatures attained as compared with the structural steel columns can be attributed largely to the lower allowable unit loads applied to cast iron, and the relatively smaller surface exposed to the fire. As judged by the direction of the lateral deflection, failure in compression appears to have started on the side having the thin- nest metal. Filling the interior with concrete (Test No. 11) in- creased the time to failure 11 min., with a smaller proportionate in- crease in the length of the expansion period. In the two fire and water tests of cast iron columns, water was applied when the columns had attained maximum expansion, the 190 GENERAL SUMMARY AND DISCUSSION metal being at low red heat. No cracks developed in the metal, the only effect being permanent lateral deflections of respectively, \y% in. and % in. toward the side on which water was applied. (3) Pipe Columns. The time to failure of the 7-in. pipe col- umn was 36 min. and maximum expansion was attained at 14 min. The 8-in. reinforced pipe column failed after 1 hr., 12 min. and maximum expansion was attained at 52 min. The column ex- panded only a small amount after 25 min., the total expansion be- ing about Y$ in. The high temperatures on the surface of the pipe indicate that during the last half of the test 'period most of the load was carried by the structural steel reinforcement. (c) Partly Protected Columns Filling the reentrant portions or interior of the structural steel sections with concrete greatly increased their fire resistance as compared with that in the unprotected condition (Table 42b, p. 124). This increase was due to slower temperature rise in the metal resulting from the heat insulating and absorbing properties of the filling, and to the load carrying capacity of the concrete, the longer time intervals between maximum expansion and failure be- ing due in great part to the latter factor. Temperature differences up to 450 C. (810 F.) existed be- tween the exposed flanges and the protected webs, the temperature of the latter at failure being generally below 500 C. (932 F.). (1) Effect of Section and Size. No decided effect due to variation in shape of structural section was noted except as it af- fected the size of the column. In Fig. 50 is shown the relation between time to failure and area of material in cross section for all tests of partly protected c o Si O 0) CO 1 rw 120 100 80 60 -40 20 n p / / u e / i: D o s j (\^ **( / / 14 * ' 17 16 , , 2 3 Time to Failure in Hours Fig. 50. Effect of size, partly protected columns. DISCUSSION OF TEST DATA 191 columns except No. 22, which was eliminated as being in effect a protected column. The relation shown accounts for the variation in results within the group, as being due in large part to difference in size. (2) Effect of Concrete Aggregate and Ties. In the tests of short duration, the concrete aggregate appears to have affected re suits to a minor extent, while in those of longer duration (Nos. 18 and 22) the results compare with those obtained for concrete protections which they more nearly resemble. Metal ties were placed in the concrete of all partly protected columns where not contained by the section members as in the lat- ticed columns. No tendency was noted on the part of the filling to spall, buckle, or otherwise come loose before failure. The extent to which the ties functioned to prevent such effects is not fully de- terminate although in tests of concrete protections made with the same aggregates, little cracking or spalling was noted within the given time periods. (d) Plaster on Metal Lath Protections (1) Material and Design. The Portland cement plaster, of proportion 1 : 1/10 : 2^2 volume parts of Portland cement, hydrated lime and coarse lake sand, as mixed by the workmen for the pro- tections and tested in 2-in. cubes, developed an average compressive strength of 1677 Ib. per sq. in, at 28 days and 2623 Ib. per sq. in. at an average age of 16^-2 months, with maximum range in individual tests of 44 percent below and 60 percent above the given averages (Table 25, Fig. 23). Cubes made in the laboratory of the same ma- terials and average water content (16.7 percent) gave lower com- pressive strength, both as stored in air and in water (Table 28, p. 371). The metal lath was wrapped around the structural steel columns on. bars or on pressed steel channels acting as spacers, and the plaster applied in layers % in. to 1^ in. thick, each consisting of two body coats. The double layer protections had a %-in. air space between layers. For the cast iron column the plaster was applied on high- ribbed metal lath supported directly on the column. A broken air space of about J^ in. thickness was formed next to the metal due to failure of the plaster to fully fill the space back of the lath. (2) Test Results. The average time to failure of the structural steel columns with single layer protection was 1 hr., 16 min., and of those with double layer protection, 2 hr., 38 min., the two tests of each varying from the average by less than 15 min. (Table 42c, p. 124). The cast iron column protected by a single layer of \y 2 192 * GENERAL SUMMARY AND DISCUSSION in. average thickness with a broken space between it and the iron (Test No. 27) stood up longer by a few minutes than any of the other columns in the group. The temperature distribution across the section was generally very uniform and the variations in the length of the column were not large (Figs. 97 and 98, p. 272-273). This was due to the airspace between the covering and the structural section which permitted free heat interchange in the column, unmodified by the temperature gradients in the covering material. (3) Cracking Due to Expansion of Covering. During the first 20 min. period in all tests of Portland cement plaster protec- tions, cracking and disruption of the plaster took place below the bracket near the top of the column. This was evidently due to expansion of the plaster layer which was restrained at the top of the column and at the bottom bearing. This effect appears to have had little influence on the time to failure in the given tests, the region of maximum column temperature and failure being in all cases within the middle 4 ft. of the column height. The sand used in the plaster was high in insolubles (chiefly silica) and low. in calcite and dolomite (Table 14, p. 357). (4) Effect of Variation in Details of Application. Comparing the layer thickness of Test No. 23 where the plaster was applied on expanded metal lath, with that of Test No. 24, where woven wire lath was used, and also the outer layer thickness with the inner in Test No. 110, applied respectively on expanded metal and on woven wire, a heavier layer thickness by j in. was attained in all cases, with the expanded metal (Tables 3d and 4d). This difference in layer thickness may account in part for the longer test duration of No. 23 as compared with No. 24. Further indications that layer thickness is an important element in the protection given, is had in the case of Test Nos. 25 and 26, where with a difference in layer thickness of ]/% in., a difference in time to failure of 16. min. obtains. The tests developed no evidence that the method of supporting the lath had any influence on results (cf. Sec. IV, par. 2a, p. 63). All double coverings had an air space about 24 i n - wide between the inner and outer layer. No tests were made with a single layer equivalent in thickness to that of two double layers, hence no direct evidence relative to the value of the air space as on insulating medium was obtained. (5) Effect of Water Application. The water carried away some loose pieces near the top of the column where cracking and DISCUSSION OF TEST DATA spalling had taken place during the fire period (Fig. 87). It ex- posed the lath at the corners of the outer layer for portions of the height. The test did not appear to have materially injured the in- sulating value of the covering since the time to failure in the sub- sequent fire test nearly equalled that of the corresponding test (No. 23) in the fire series (Table 44, Test No. 110). (e) Concrete Protections (1) Mechanical Properties of the Concrete. The compressive strength of 8 by 16-in. cylinders made from 1 :2 :4 gravel or crushed stone concrete mixed for the column coverings under conditions approximating those of building practice, averaged 1520 Ib. per sq. in. at 29 days and 2100 Ib. per sq. in. at an average age of 15 months, the maximum range of individual test results being 118 per cent above and 57 percent below the given average values (Table 21, p. 361). As shown in Fig. 15 (p. 75), the range in results increased with the number of tests in the group, indicating that in the groups with the smaller number of tests the full possibility of variation was not developed. The principal cause of the variation in strength was apparently difference in consistency of the concrete mixtures. Increasing the time of mixing from 1 min. to 2 min. gave an indicated increase in the average compressive strength of 45 percent (Fig. 19, p. 78). The modulus of elasticity of the concrete varied approximately with the compressive strength, from less than 1,000,000 to over 4,000,000 Ib. per sq. in. (Fig. 21, p. 79). This large variability in the mechanical properties of the concrete appears to have had little influ- ence on its fire resistive properties, the latter depending chiefly on the mineral composition of the aggregates employed, (2) Function of Concrete as a Covering Material. Concrete applied as a protective covering or filling to steel or cast iron col- umns, retards the temperature rise in the metal when the .column is exposed to fire and further retards the failure by carrying por- tions of the column load proportionate to its relative area and rigid- ity as compared with the metal. The protections were applied as square or round coverings, generally 2 in. and 4 in. in thickness as measured from the surface of the covering to the metal. The time to failure in the fire tests, varied from 1 hr., 47 min. to 7 hr., 57 min. for the 2-in. protections, and from 3 hr., 41 min. to over eight hours for the 4-in. protections (Table 42d, p. 125). 194 GENERAL SUMMARY AND DISCUSSION (3) Variations due to Concrete Aggregate. With a given thickness or size of covering the main cause of variation in results was the difference in fire resisting properties of concrete made with different aggregates. In this particular the concrete can be placed in three groups. That giving the most unfavorable results was the concrete made with Meramec River sand and gravel, a number of large cracks forming early in the tests followed by spalling of large and small pieces of concrete not held by the ties (Test Nos. 39 and 45). This sand and gravel consist almost wholly of quartz and chert grains and pebbles, the gravel having a particularly high chert content. Both minerals are forms of silica (SiO 2 ), the quartz being crystalline and anhydrous, and the chert amorphous with a variable amount of water in chemical combination. On being heated part of the combined water in the chert is liberated and the consequent vaporization disrupts the pebbles. Other causes of disruption of concrete made with siliceous aggregates are abrupt volume changes, points of which are known to exist for chert as low as 210 C. (410 F.). Quartz has a decided point of abrupt volume change at 573 C. (1064 F.), where it is transformed into the mineral tridy- mite, the change extending over a considerable temperature range when the heating is rapid. Water inclusions contained in small cavities formed when the rock crystallized from the molten con- dition may be the cause of some of the cracking incident with fire exposure. The middle group includes concrete made with trap rock, gran- ite, sandstone and hard coal cinder. In tests with trap rock and cinder concrete a small amount of cracking developed during the last part of the fire period but no spalling of note occurred before failure. In the granite concrete pro- tections the cracks developed earlier in the test and portions of the corners spalled off during the last 30 min. of the test period. In the tests with sandstone concrete protections, cracking and spall- ing of corners outside of the wire tie began in the first 30 min. period and continued during the next hour, after which there was little apparent change before failure. The spalling exposed por- tions of the flange edges which to some extent hastened the failure. The average time to failure in tests with sandstone concrete pro- tections was intermediate between those with trap rock and those with cinder concrete. The cracking of sandstone concrete after a short fire exposure can be ascribed mainly to the abrupt volume change of the constituent quartz grains as noted above. DISCUSSION OF TEST DATA 195 Fusion of the trap rock concrete occurred where the test ex- tended beyond seven hours, the concrete being affected to a depth of about \ T /2 in. Flowing of concrete due to fusion, while not gen- eral, occasionally formed pockets up to 2-in. depth. Incipient fusion to about the same depth occurred in the 4-in. granite con- crete protections, although no actual flowing of concrete took place. The third group comprises protections of Chicago limestone concrete and Joliet gravel concrete. The composition of this gravel is similar to that of the Chicago limestone and the fire resist- ing properties of the concrete made with each compare quite closely. Very little cracking resulted on exposure to fire and their heat in- sulating value was increased by the change of the calcium and mag- nesium carbonate to the corresponding oxides. This process re- tarded the flow of heat through the region of change and left material of good insulating properties. Immediately after test the surface of the concrete was firm, but after a few weeks exposure the hydration of the oxides caused slaking and crumbling of the calcined material (Fig. 62, p. 235). / 4 <$'< f 39 363?A3I I 43 .38 ?8 X Z8A30 34 3 A Time to Failure in Hours Fig. 51. Comparison of 2-in. and 4-in. concrete protections. (4) Comparison of 2-in. and 4-in. Protections. In the com- parison given in Fig. 51, the tests of concrete protections are ar- ranged by groups as defined in the preceding paragraph, the line in the case of the middle group connecting the average value for each thickness. Test Nos. 40, 46 and 47 are omitted in this com- parison on account of extreme shape and size of section and No. 44 on account of leaner concrete mixture. 196 GENERAL SUMMARY AND DISCUSSION The time to failure under working load was not determined for the 4-in. limestone concrete protections, as they were loaded to failure after withstanding the fire test in excess of eight hours. They all attained maximum expansion within the last 30 min. of the 8-hr.' fire period, and from comparison with results obtained with the corresponding 2-in. protections, failure in the case of the 4-in. protections would not have taken place before the end of ten hours, assuming the same load and the same furnace temperature rise as obtained during the 8-hr, period. (5) Effect of Size. In Fig. 52 the time to failure in tests with concrete protections of the middle group is plotted against the area of steel and concrete in the cross section. Variations from - ' o CDU 240 220 200 ISO 100 140 120 100 80 fin J4A J4< ^. -*" ^ ^" 40 ^ ^ *^~ 37 44 o 4 3 ^ <"" 3 J64 o ^. V -^ ,^ J did ^ X o 36 4 7 - 6 2345 ^ Time to Failure in Hours Fig. 52. Effect of size, concrete protections. the general trend can be accounted for as due to concrete aggregate, proportions of concrete mixture, type of section, and to incidental differences in test conditions and test columns. The extreme varia- tion in furnace exposure as measured by the area under the furnace temperature curves is within 2 percent as between all the tests plotted, except Nos. 34 and 34A, between which there is a difference of 4 percent (Table 42d), which latter may be responsible for the difference in failure time of the two tests. (6) Effect of Strength of Concrete. Some decrease in fire resistance due to leaner mixture -may be noted by comparison of Nos. 33 and 33A with No. 35 and No. 43 with No. 44. No evidence was developed that variation in the strength of the concrete of the same aggregate and proportion of mixture had any appreciable influence on the results of fife tests of concrete pro- tections. This was due to the large change in mechanical proper- DISCUSSION OF TEST DATA 197 ties produced by the heat. Concrete as made with different ag- gregates preserves strength to different degrees on exposure to fire. This had a decided influence on results, the longer test peri- ods and particularly the longer intervals between maximum ex- pansion and failure of the limestone concrete and Joliet gravel concrete coverings can be attributed in a great part to this cause. (7) Influence of Shape of Section and Covering. As in the case of the partly protected columns, the only well defined effect of change in shape of structural section was primarily due to the resulting difference in the area of steel and concrete. Round and square coverings of trap rock concrete displayed only minor difference in the number and size of cracks that de- veloped before failure. Fine vertical cracks two to four inches from the corners formed in the square coverings at somewhat earlier periods than the first cracks noted in the round coverings. In' neither case do these cracks appear to have had any appreciable in- fluence on the time to failure. Coverings made of concrete more subject to cracking may possibly develop greater 'differences due to shape, although with concrete made with highly siliceous aggre- gates, the influence of the aggregate is so large that other effects are small in comparison. This is shown in test No. 45 where the round siliceous gravel concrete covering sustained severe cracking and spalling early in the test which caused failure over one hour earlier than in any other test of concrete protection. (8) Function of the Wire Tie. In all tests of concrete pro- tection except Nos. 28A, 33 A and 47, the concrete was tied by a wire wound spirally around the structural steel section. In Nos. 28A and 33A the concrete aggregate was Chicago limestone. No cracking of consequence developed before the end of these tests and the absence of the tie had no influence on the results. In the case of the cinder concrete protection in Test No. 47, no cracking of note occurred until near failure and after the column had sustained large compressive deformation. About two minutes before failure most of the covering fell off. This would have been prevented if the wire tie had been present, although the temperature of the metal and the deformation of the column was such that failure was imminent. r '-'';**! It is not possible to state the extent to which the tie functioned in all tests of concrete protection, but it was undoubtedly of value where there was any tendency for the concrete to crack and fall off before failure. In the case of Meramec River gravel concrete and 198 GENERAL SUMMARY AND DISCUSSION sandstone concrete, spalling of portions of the covering outside of the tie occurred early in the test, the concrete on the middle of the flanges and webs being apparently held by the ties. (9) Effect of Water Application. In the three tests where the wire was placed in the coverings, the water pitted the exposed faces of the concrete and carried away portions of the corners and sides, leaving parts of the flanges and flange edges exposed. The damage was most marked in the regions where cracking was noted during the fire period (Figs. 83 and 84, p. 256-257). In the case of the one covering that was not tied, the water loosened or carried away more of the protection on the flanges, leaving the column in the condition of partial protection. Most of the damage was incurred after 2 min. of water application, the total period being 5 min. (f) Hollow Clay Tile Protections (1) Mechanical Properties of the Tile. The average cotn- pressive strength of specimens of the hollow clay partition tile used in the column coverings was 5350 Ib. per sq. in. as tested on end and 4370 Ib. per sq. in. tested on edge, the maximum variation above these values being 134 percent and below, 78 percent, of the lower average value. For the same type of clay the range in results was smaller. The strength was generally proportional to the density of the tile as indicated by percentage of porosity and of absorption (Table 31, p. 373-374). In transverse tests of hollow tile the average computed outer fiber stress at failure was 527 Ib. per sq. in. and the shear 233 Ib. per sq. in., the failure being apparently due to combined shear and tension. The range in results was larger than in the compression tests (Table 32, p. 375). There appears to be little relation between the mechanical strength and the fire resistive properties of the tile, the latter de- pending mainly on the type of clay. This is significant as specifi- cations based on the mechanical properties often disqualify tile de- sirable from the standpoint of resistance to fire. (2) Test Results. In tests of hollow clay tile protections using tile of the given types of clay applied according to the meth- ods previously described, the time to failure ranged from 50 min. to 4 hr., 42 min. This large range in results was due to a number of factors that influence the effectiveness of this type of protection, including, besides type of clay, methods of manufacture of the tile, thickness of shells and webs, the presence or absence of concrete or other filling back of the tile, and the methods used for tying the tile (Table 42e, p. 126). DISCUSSION OF TEST DATA 199 (3) Variations Due to Type of Clay and Details of Manu- facture. The extent to which the tile cracked and spalled on ex- posure to fire varied with the type of clay of which it was made and the degree of hardness to which it was burned. All of the tile used in the coverings was straight non-porous partition tile, burned with- out sawdust or other filling, except the round tile in Test Nos. 62 and 63 which was porous. The semi-fire clay tile generally gave the most favorable re- sults in the fire tests, and of the two represented, the tile of medium hardness and having heavier webs and shells, developed few cracks and little spalling before failure. In the coverings of round porous semi-fire clay tile, a number of .vertical cracks formed after a short fire exposure which became wider as failure was approached. Few other disruptive effects were noted, almost all material remaining in place till the end of the test. Only minor differences in behavior were noted between tile made of the two kinds of surface clay, cracking and spalling of outer shells and bucking out of the tile being characteristic of tests of both. In the case of shale tile, these effects were even more pronounced, severe cracking taking place during the first few minutes of the test, followed by general spalling of outer shells. (4) Comparison of 2-in. and 4-in. Protections. In Fig. 53 is given a comparison of time to failure in tests with 2-in. and 4-in. 2 3 Time in Failure in Hours i g- 53, Comparison of 2-in. and 4-in. hollow clay tile protections. 200 GENERAL SUMMARY AND DISCUSSION hollow clay tile protections, all other details being comparable ex- cept as noted. The tests show little difference between the two, the thickness of the air space and minor variations in thickness of shells having apparently little influence on results. The difference in results in Test. Nos. 50 and 50A as compared with 51 and 51 A can be attributed to larger differences in thickness of shells and webs and also to the greater strength and stability of the 4-in. tile set on end and tied with outside wire ties, as against the 2-in. tile laid flat in 6-in. courses without ties (p. 151-152). (5) Effect of Size. In Fig. 54 is shown the relation between the time to failure in all tests of hollow clay tile protections made with non-porous partition tile, and the total area of steel, tile, mor- _ c f* 5 c WU aoo 80 260 ^ ' ^ ^ ^ 5^ 59 ^ ' 40 220 200 '180 160 I4O I2O IOO 80 ( 57 fS ^71 b o U 54 S* *" 510 j ilA S* -56 >6 68 ^ ^ P 53 & ^* ^ ^ S ^ So 4 Rn 50t 61 55 ) 1 < = 3 -4 5 Q 7 G Time to Failure in Hours Fig. 54. Effect of j*sr0, clay tile and brick protections. tar and filling in the cross section, a fairly consistent variation of the time to failure with area being evident. Nos. 58 and 59, having double layer of tile with tile filling, gave less favorable results in this compar- ison than tests of protections with a single layer of tile and concrete fill. (6) Effect of Ties and Filling. Fig. 55 gives a comparison of results attained with the two methods used for tying the tile and of including or omitting the concrete or tile filling. As sliown on the diagram, and confirmed by test characteristics, the mesh in the horizontal joints is a little more effective in holding the tile than the outside wire ties, also, the concrete or tile filling is an important DISCUSSION OF TEST DATA 201 element in the protecting property of a hollow tile protection. The efficiency of wire mesh in the joints as against outside wire ties, in the case of protections of surface clay tile with hollow tile filling, is shown by comparison of results in Test Nos. 58 and 59. It should be considered in this connection that minor parts of the difference may be due to incidental variations in workmanship and test conditions, and also that protections of tile less subject to cracking and disruption on exposure to heat would show relatively smaller differences in results due to the methods used for tying the tile. Concrete or Tile FiUing. Wire Mesh in Horizon- tal Joints Concrete or Tile Filling. Outside Wire Ties.. No Filling. Out- side Wire Ties.. i a 3 Time to Failure in Hours Fig. 55. Effect of ties and filling, hollow clay tile protections. The concrete filling not only serves as a protecting medium but also assists in holding the tile in place by adhesion. In Test No. 60 the concrete filling was placed before the tile was set, the tile being bonded to the filling with a^thin mortar joint and tied with outside wire ties. A large number of tile units fell off early in the test, the behavior in this particular being distinctly different from that of protections with concrete fill placed after the tile was set, where up to points near failure, the inner shell generally remained in place. As indicated by the average temperatures in the steel at failure, the concrete filling carried portions of the applied load varying with the area, the higher temperatures at failure being generally inci- dent with the tests having the larger fills. In the latter tests the periods between maximum expansion and failure were comparable with those obtaining for concrete protections, whereas in the tests where the concrete fill was omitted or of small area, this time in- terval was relatively short (Table 43, p. 136). 202 GENERAL SUMMARY AND DISCUSSION (7) Effectiveness of Plastering. The tile in Test Nos. 76 and 77 were covered with standard applications of gypsum and of lime plaster, respectively, applied 3 days after the concrete fill was placed, the columns being tested 42 and 45 days after plastering. In Test No. 76 the gypsum plaster began to fall off early in the test, exposing a few tile units at 2 min. and more than half of the tile surface at 20 min. General cracking and spalling was prob- ably delayed to some extent by the insulation given the tile by the plaster during the first few minutes of the fire exposure. The lime plaster in Test No. 77 fell off during the first half min- ute of the test exposing about three-fourths of the total tile surface, its influence on the test result being apparently very small. These results with plaster may not be applicable where it has seasoned for a longer time, and without further tests, they should not be taken to hold rigidly for well cured plaster coatings that from conditions of normal exposure are thoroughly dry. (8) Effect of Water Application. The water generally car- ried away the tile that had been decidedly damaged during the pre- ceding fire exposure, although adjacent courses of relatively sound tile were in some instances carried down along with those impaired by the fire (Figs. 84 and 85, p. 257-258). A large proportion of the ef- fects took place during the first minute. In the test where the space between the tile and column was filled with concrete, the condition of the column after the water application approached that of partial concrete protection. In the case of the unfilled columns, the steel in the region stripped of tile was unprotected except for the por- tions of the mortar joint that adhered to the flanges. No decided difference was noted between the outside wire ties and the wire mesh in the joints in effectiveness in holding the tile during the water application althougll the comparisons were too few to afford definite conclusions. (g) Brick Protections (1) Properties of the Brick. The common brick used irr the brick protections was a wire end cut brick made in the Chicago, 111., district of calcareous surface clay. .Compression tests gave average values of 3200, 1960 and 2815 Ib. per sq. in. as tested on end, edge and side, respectively, and average transverse strength of 862 Ib. per sq. in. with maximum variations above or below the averages of between 50 and 100 percent (Tables 35 and 36, p. 377). The brick was soft, with relatively low fusion point and high percentages of porosity and absorption (Tables 33 and 34, p. 376). DISCUSSION OF TEST DATA 203 (2) Test Results. In the two tests of columns protected by brick, approximately the same relation obtained between time to failure and sectional area of the covered columns as for the hollow clay tile protections (Fig. 54, p. 200, Nos. 68 and 69). In No. 68 where the brick was set on edge and end, the lack of stability considerably shortened the test, a large amount of brick falling during the first 30 min. (Table 42g, p. 127). In No. 69 with the brick laid flat, little cracking or spalling developed before failure. Fusion of the brick began between the fourth and fifth test hours, and after test the brick was found fluxed away to a depth of about one-half inch. The uniform temperature rise in the metal indicates that the fusion of the brick did not con- tribute greatly to the failure of the column, the same being evi- dently caused by normal transmission of heat, through the cover- ing (Fig. 131, p. 306). (h) Gypsum Block Protections (1) Strength and Porosity of the Gypsum Block. Compres- sion tests of the solid gypsum block used for column covering gave an average strength of 468 Ib. per sq. in., with maximum range in values of 22 percent below and 40 percent above the average. The transverse strength averaged 160 Ib. per sq. in., the extreme range in results of individual tests being a little higher than in the com- pression tests (Tables 38 and 39, p. 378-379). The porosity was quite uniform and high, averaging 62.4 per cent, as based on the total volume (Table 37, p. 378). (2) Comparison of 2-in. and 4-m. Protections. A comparison in point of time to failure of 2-in. and 4-in. gypsum protections is given in Fig. 56, where the line connects the average results at- tained with each thickness. The 2-in. protections withstood the fire test 2 hr., 22 min. and 2 hr., 36 min. and the 4-in. protections, 4 hr., 43 min., 5 hr., 32 min. and 6 hr., 24 min., respectively (p. 127). The protections were of solid 2-in. and 4-in. partition blocks set in gypsum and sand mortar, 2/4 to 1^4-in. thick between blocks and column flanges, and with metal ties in the horizontal joints, the space between the blocks and the column webs being filled with gypsum block set in place or with a filling poured in place consist- ing of calcined gypsum, sand and broken gypsum block. The variations in results obtaining for each thickness of cover- ing come within limits where they can be ascribed to incidental dif- ferences in material, workmanship and test conditions, considering that the duration of the test was dependent upon the stability of in- dividual blocks. 204 GENERAL SUMMARY AND DISCUSSION bfl DISCUSSION OF TEST DATA 205 23 A 5 6 7 Time to Failure in Hours Fig. 56. Comparison of 2-in and 4-in. gypsum block protections. (3) Characteristic Fire Effects. The gypsum coveri'ngs failed due to checking, shrinking and disintegration of the blocks which caused them to loosen and fall off. Characteristic heat effects are shown in Fig. 57. The process responsible for these effects con- sists mainly in the transformation of hydrated gypsum of the for- mula, 'Ca SO 4 +2H 2 O, to anhydrous calcium sulphate, by evapora- tion of the chemically combined water. Failure of the column occurred within 20 to 40 min. after the first blocks had fallen. The interval between maximum expansion and" failure was relatively short, due to the rapid temperature rise in the steel and the low load carrying capacity of the covering ma- terial that remained in place. (4) Heat Insulating Properties. The maximum temperature in the steel up to the point where the blocks began to fall off was generally below 150 C. (302 F.), which was much lower than those obtaining in comparable tests with the other covering ma- terials after the same duration of fire exposure (Figs. 127 to 130, p. 302-305). The high heat insulating value of gypsum is due in part to the heat consumed by the change in crystalline structure noted above. (5) Effect of Water Application. In the case of the 2-in. protection, the effect of the first 2 min. of the water application was confined to washing away of the partly calcined gypsum near the outer face of the covering, all blocks remaining in place. During the third minute most of the blocks on the sides on which water 206 GENERAL SUMMARY AND DISCUSSION was applied were carried down along with portions of the poured filling (Fig. 86, p. 259). On the 4-in. protection the water application of 5-min. dura- tion washed away the gypsum on three sides to a depth of 1-in. from the surface, all blocks remaining in place. (i) Reinforced Concrete Columns In the reinforced concrete columns of the fire test series, the coarse concrete aggregates used were Chicago limestone and New York trap rock and the application of the results should be limited to columns made with these concrete aggregates. Comparisons given in paragraph (e) above on the behavior of concrete made with these and other aggregates and applied in coverings for steel columns, indicate that less favorable results would be obtained with- some of them when applied in reinforced concrete columns than was obtained with the columns tested. Also in the fire and water tests, the sections of the columns made of siliceous gravel concrete de- veloped much greater disruptive effects during the relatively short fire exposure preceding the water application than the sections made of limestone or trap rock concrete. The behavior of lime- stone and trap rock concrete in tests of reinforced concrete columns was similar to that of the corresponding concrete of the column coverings (p. 194-195), little cracking or spalling of consequence oc- curring before failure. (1) Influence of Concrete Aggregate. The limestone con- crete columns all withstood the 8 hr. fire test and while hot sus- tained loads exceeding twice the load applied in the 8-hr, period. The two vertically reinforced trap rock concrete columns failed after 7 hr., 23 min. and 7 hr., 57 min., respectively, and the hooped column withstood the 8-hr, fire test and failed under a load about 25 percent greater than the load sustained during the fire test (p. 128). A 2-in. thickness of concrete next to the surface was assumed as covering in all cases and not included in the area used in computing working loads. The difference in results within the group can be attributed to concrete aggregate, the other incidental factors being comparable or favoring the tests giving the lower results. The trap rock concrete fused and fluxed at some points to a depth of about one inch, which undoubtedly affected the time to failure to some extent. The results obtained with the concrete of both ag- gregates show a high degree of fire resistance. (2) Effect of Form of Column and Reinforcement. No ef- fects due to shape of column or form of reinforcement were evident, differences in results being within the limits 'of incidental varia- tions in test columns and test conditions. DISCUSSION OF TEST DATA 207 No line of cleavage outside of the wire reinforcement was found after test in the hooped column of limestone concrete, ex- cept in the immediate region of failure, where it was apparently induced by the strains that developed when the column failed. In the case of the corresponding trap rock concrete column, more evidence indicating separation of the outer protection from the core at the line of the reinforcement was found, effects which may in part have been caused by the fire exposure. (3) Recovery of Strength after Fire Test. One length of each of the hooped reinforced concrete columns about three feet long was cut outside of the failure region in the fire test and sub- sequently tested in compression. The limestone concrete speci- men sustained a total load of 517,000 Ib. as against 243,000 Ib. im- mediately following the fire test, and the trap rock concrete speci- men, 342,000 Ib., compared with 163,000 Ib. at the end of the fire test. While a portion of the difference may be due to initial varia- tions in the strength of the concrete, the greater part can be ascribed to recovery in strength of concrete and reinforcement. (4) Effect of Water Application. The concrete of the col- umns subjected to fire and water tests was placed in three sections to permit using two or three kinds in each column. In the case of the square vertically reinforced column, No. Ill, the water carried away the concrete at the corners outside of the bars and pitted the concrete on the most exposed face to depths of from ]/% in. to 1 in. for the limestone concrete and to a depth of 2 in. for the Meramec River gravel concrete in tfie middle section (Fig. 88, p. 261). In the round vertically reinforced column, the limestone con- crete was pitted to a depth of 1 in. and some of the concrete in the upper portion of the Joliet gravel concrete section was carried away. In the middle section, consisting of Meramec River gravel concrete, the outer concrete was stripped off by the water, expos- ing the reinforcing bars on two sides. In this as in the preceding test, large cracks had formed in the concrete of the middle section during the fire period. In the fire and water test of the hooped reinforced concrete column, the water stripped the Meramec River gravel concrete and the granite concrete from the wire reinforcement on three sides during the first 15 seconds of the water period (Fig. 89). Spalling of concrete had exposed portions of the reinforcement in the middle section during the fire period. Further application of water caused stripping to the reinforcement in the upper section of trap rock con- crete and increased the effects in the lower sections. 208 GENERAL SUMMARY AND DISCUSSION The condition of none of the reinforced concrete columns was such as to cause apprehension of early failure on being again exposed to fire after the water test, since the proportion of the load normally carried by the steel reinforcement was not large. Load tests to failure made after the water test gave factors of safety of over 4 as based on the calculated working load. (j) Timber Columns Six tests of timber columns were made, four being tested un- protected. One was protected by a single layer of Portland cement plaster on metal lath and one by a single layer of gypsum wall board. Two species of wood, longleaf pine and Douglas fir, and two types of post cap details were employed (Fig. 10, p. 33). (1) Unprotected Timber Columns. The time to failure of the unprotected timber columns varied from 35 to 50 min. (p. 128), failure occurring in all cases at the bearings on the steel or cast iron cap introduced near the top of the column (Figs. 80 to 82, p. 253-255). The deformation at the bearing increased rapidly after the first 20 min. and at failure the consequent depression equalled three inches or more (Fig. 47, p. 140). The average time to failure in the tests with longleaf pine was nearly the same as that obtained with Douglas fir, although the tests were hardly comparable on account of the higher moisture content of the Douglas fir in the condition tested (Table 2, p. 34). The columns with the cast iron cap and pintle stood up 7 min. and 15 min. longer than the columns with the steel plate cap, the deformations sustained by the wood at the cap before failure en- sued being larger in the case of the cast iron bearing. (2) Protected Timber Columns. The outer coat of the plaster on parts of the lower half of the metal lath and plaster protection (Test No. 78) spalled during the first half hour of the fire test, followed later by local buckling out of lath and supporting channels. Flames from the column issued through this opening before the end of the first hour and about fifteen minutes later flames issued from cracks in the plaster around the column cap. Crushing of the wood at the bearing due to heating of the cap caused a rapid rate of depression beginning at 1 hr., 40 min. (Fig. 47), failure accompanied by fracture of the cap occurring at 2 hr., 15 min. (Fig. 79, p. 252). The wall board consisted of gypsum plaster filling between paper facings. At 20 min. flames issued from horizontal cracks in the plaster board. The board began to fall off the body of the column at about 40 min. and at 54 min. nearly one-half of the cover- ing had fallen. At 32 min. part of the covering fell off the flanges DISCUSSION OF TEST DATA 209 of the steel plate cap, the failure at 1 hr., 13 min. being due to slipping at the cap bearing same as for the unprotected timber columns (Fig. 81, p. 254, Test No. 80). The protections increased the ultimate resistance of the columns by 100 to 200 percent as compared with that in the un- protected condition. Protections on timb'er columns should be applied with due consideration for possible deterioration from dry rot that may under certain conditions be induced by the presence of the coverings, particularly when the wood is not fully seasoned or where it is exposed to dampness. (3) Strength After Fire Test. The failure being localized at che bearing did not develop the full resistance of the column. The wood was burnt and charred to depth of J4 in- to 1^4 m -> involving reductions in effective area of 29 to 55 percent. One specimen 3 ft. long was cut from each of the tested columns and tested in compression about ten weeks after the fire test. The results of the tests are given in Table 45 where also are given results of tests on comparable specimens of unburnt timber. The results indicate a reduction in the total load approximately in proportion to the reduction in area, the average of the maximum unit loads sus- tained by the burnt and unburnt timber of each species being nearly equal. The strength remaining in the timber at the end of the fire test was considerably lower than the values given in Table 45, due to its heated condition. TABLE 45.-COMPRESSIVE STRENGTH OF TIMBER AFTER FIRE TEST Specimens 3 ft. long Spec- imen No. Section Before Test Section After test Reduc- tion, Percent Mois- ture Con- tent, Percent Maximum Load Species Outside Dimensions, In. Area, Sq. In. Outside Dimensions, In. Effec- tive Area, Sq. In. Total, Lb. Lb.per Sq. In. 78-1 79-1 80-1 81-1 82-1 83-1 P-l F-l F-2 Longleafpine Longleaf pine Longleaf pine Longleaf pine Longleaf pine Douglas fir . . Douglas fir . . Douglas fir. Longleaf pine Douglas fir. . Douglas fir. . Douglas fir. . ll.Sby 11.5 11.2 by 11. 2 11.2by 11.3 11.4by 11.4 129 , 125 126 129 7. 9 by 8. 4 8. 8 by 9.1 9.0 by 9.0 9.0by9.1 58 76 75 77 55 44 40 40 15.5 14.4 15.8 16.2 370,000 381,000 399.000 475,000 6380 5010 5320 6170 5720 3725 4395 15.5 11. 4 by 11. 4 11. 4 by 11.4 129 129 9. 5 by 9. 5 10. 6 by 10.7 87 91 33 29 22.7 18.8 324,000 400,000 Average 11. 2 by 11. 4 11. 4 by 11.4 11. 4 by 11.4 20.7 19.3 18.9 18.9 750,000 502,000 500,000 4060 5705 3890 3875 127 129 129 Specimen of Specimen of Specimen of unburnt unburnt unburnt timber. timber, timber. 18.9 3880 *Determined from samples taken near point of failure, dried to constant weight at 100 C. XIII. FIRE RESISTANCE PERIODS DERIVED FROM THE TEST RESULTS The results of the tests, in point of time to failure, will be summarized in terms of hours and minutes of fire resistance af- forded by the different types of column and protections tested. 1. BASIS OF DERIVATION (a) Method of Computation A given resistance period is taken to hold, if the time to failure in the fire test, or the average of the time to failure in a group of similar tests, is equal to one and one-half times the given resistance period. The deduction of one-third of the test duration is made to allow for incidental variations in material and workmanship of columns and coverings, and differences in load and fire condi- tions that cause variations in results with nominally comparable columns. Individual test results within a given group may be below this limit but not below the designated resistance period. (b) Intervals Resistance periods are taken 5 min. apart up to one-half hour, at 15-min. intervals from one-half hour to one hour, at one-half hour intervals from one hour to four hours and at one-hour inter- vals from four hours to eight hours. A tolerance of % of an inter- val is allowed, a given even value of the resistance period being taken if the period, computed according to the method given above, is not more than % of the interval below the given period value. (c) Table of Fire Resistance Periods A tabulation of the fire resistance periods obtained from the results of the present series of tests is given in Table 46. 210 TABLE OF FIRE RESISTANCE PERIODS 211 TABLE 46. FIRE RESISTANCE PERIODS DERIVED FROM THE TEST RESULTS Type of Column PROTECTION Minimum Area of Solid Material, Sq. In. Nominal Thickness of Protection, In. Fire Resistance Period Material Details Structural stee' Structural steel, solid section Structural steel, solid section Structural steel, open latticed section Structural steel, open latticed section Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Structural steel Unprotected Partly protected by fill- ing reentrant spaces with concrete. Con- crete aggregates limestone, calcareous gravel, trap rock granite, sandstone or hard coal cinder Partly protected by fill- ing reentrant spaces with concrete. Ag- gregates; limestone calcareous gravel or trap rock Partly protected by fill- ing interior and re- entrant spaces with concrete; trap rock aggregate Partly protected by fill- ing interior and re- entrant spaces with concrete; limestone or calcareous gravel ag- gregate Portland cement plaster on metal lath do Minimum metal thick- ness, .20 in. Mixture, 1:6 or 1:8. Con- crete tied with verti- cal and horizontal steel ties do 8 35 60 120 120 40 80 100 200 100 140 200 100 140 200 100 140 200 10 min. l / 2 hr. Mhr. 2hr. 3H hr. Mhr. 1V4 hr. Ihr. 2% hr. 2K hr. 3^hr. 5hr. 3hr. 4hr. 5hr. 4hr. 6hr. 8hr. Mixture, 1:6. Filling extends to outside rivets and covers lat- tice and main mem- bers do 1 layer lin. 2 layers each Xifc. 2 4 2 3 4 2 3 4 2 3 4 Proportion of plaster, I:l-10:2y 2 , Portland cement, hydrated lime and sand do Concrete; siliceous gravel aggregate do Mixture. 1:6. Concrete tied with steel ties or wire mesh equiva- lent to not less than No. 5 (B. & S. gage) wire on 8 in. pitch do Concrete; granite, sand- stone or hard coal cinder aggregate do Mixture, 1:6. Concrete tied as above do do do Concrete: trap rock ag- gregate do Mixture. 1:6. Concrete tied as above do do do Concrete; limestone or calcareous gravel ag- gregate do Mixture, 1:6. Concrete tied as above dp do do 212 FIRE RESISTANCE PERIODS TABLE 46. -FIRE RESISTANCE PERIODS DERIVED FROM THE TEST RESULTS Continued ' Type of Column PROTECTION Minimum Area of bulid Material, fc>q. In. Nominal r ihiCkne_s of Protection, In. Fire Resistance i eriod Material Details Structural steel, solid section Structural steel, Bolid section Structural steel, solid section Hollow tile; semi-fire clay,, medium hard. No filling Hollow tile; surface clay or shale. Concrete filling on web sides Hollow tile, extra heavy; surface clay. Concrete filling on web sides Mortar joint between tile and column flanges. Outside wire ties do 80 100 160 2, 3 or 4 2, 3 or 4 3 or 4 Ihr. Ihr. l l / 2 hr. do Structural steel Structural steel Hollow tile; semi-fire clay or surface clay. Concrete filling all around do Outside wire ties Metal ties in horizontal joints 163 160 2, 3 or 4 3 or 4 2hr. 2#hr. Structural steel, solid section Structural steel, solid section Hollow tile; surface clay. Hollow tile filling do Mortar joint between tile and column flanges and webs. ' Metal ties in hori- zontal joints Mortar joint between tile and column flanges and webs. Outside wire ties 240 240 2 lavers each 2 in. 2 layers each 2 in. 3hr. Ihr. Structural steel Structural steel Structural steel Structural steel Structural steel Round cast iron Round cast iron Common brick; surface clay do Brick set on edge and end Brick laid on side Metal ties in horizontal joints. Mortar joint between blocks and column flanges do 140 240 130 180 240 12 35 2M 3M 2 3 4 Ihr. 5hr. IVt hr. 2V4 hr. 3K hr. 20 min. H hr. Solid gypsum block. Gypsum block or poured gypsum filling do do do Unprotected; unfilled Unprotected; interior filled with concrete Minimum thickness of metal, .60 in. do Round cast iron Portland cement plaster on high ribbed metal lath Proportion of plaster, l:J :2y z , Portland cement, hydrated lime and sand 60 1 layer, 1V4 in. % in. air space 2hr. Round cast i,ron Concrete; trap rock, granite or hard coal cinder aggregate Mixture, 1:7. Concrete tied with steel ties equivalent to not less than No. 5 (B. & S. gage) wire on 8 in. . pitch 70 2 2hr. Round cast iron Hollow tile: porous semi-fire clay Outside wire.ties. Mor- tar joint between tile and column * 70 2 2hr. BASIS OF DERIVATION 213 TABLE 46. FIRE RESISTANCE PERIODS DERIVED FROM THE TEST RESULTS Concluded Type of Column PROTECTION Minimum Area of Solid Material, Sq. In. Nominal Thickness of Protection, In. Fire Resistance Period Material Details Steel pipe Reinforced steel pipe Reinforced concrete Reinforced concrete Timber, long- leaf pine or Douglas fir Timber, long- leaf pine or Douglas fir Timber, long- leaf pine or Douglas fir Unprotected. Filled with concrete Unprotected. Filled with concrete and re- inforced in the fill with structural shapes Limestone or calcareous gravel concrete Trap rock concrete Unprotected Gypsum wall board Portland cement plaster on metal lath Concrete mixture, 1:1^:3 Concrete mixture, 1:1^:3 Mixture 1:6. Concrete reinforced with ver- tical bars and lateral ties or hooping * do 35 45 220 220 120 140 160 25 min. Mhr. 8hr. 5hr. 25 min. Khr. l^hr. 2 2 Unprotected cast iron or steel cap Cast iron or steel cap Cast iron or steel cap. Proportion of plaster, 1:^:2^, Portland cement, hydrated lime and .sand 1 laver, %in. 1 layer, 1 in. with % in. air space (d) Derivation of Method The method of computation is obtained from comparison of duplicate or nearly duplicate column tests, considered in connec- tion with conditions affecting comparable column constructions in buildings. In the fire tests, the maximum range in time to failure of unprotected structural steel columns was 49 percent, comparable tests of partly protected steel columns gave a range in values of 24 percent, plaster on metal lath protections, 15 percent, and 2-in. concrete protections, 25 per cent, all percentages being based on the highest value within the group. The time to failure in three tests of unprotected cast iron columns differed by less than one per- cent. In hollow clay tile protections, excluding Nos. 50 and 50A on account of not being tied, the maximum range in test duration within a group of comparable tests was 30 percent, and in gypsum block protections, 26 percent. Unprotected timber columns with exposed steel or cast iron caps gave a range in time to failure of 30 percent part of which was due to difference in bearing details. 214 FIRE RESISTANCE PERIODS In the case of unprotected structural steel columns, the range in shape of section tested was large and a deduction of one-third from the average time to failure gives a period below which test results, obtained under comparable load and fire conditions, are not likely to fall, with the limitations in thickness of metal and area of section given in Table 46. All of the other variations noted above come within 30 percent of the highest value in the respective groups, although it is appreciated that the test duplications were not sufficient in number tp develop the full possibility of difference in results, also, that columns and protections in buildings are sub- ject to greater variability than the test columns. The basis of derivation adopted assumes possibility of variation of about 33 per- cent above and below an average value or a total of about 66 per- cent of the average. Irrespective of whether or not this range in results would fully develop in a sufficiently large number of com- parable cases in buildings, the use of the one-third reduction to obtain minimum ultimate fire resistance periods is considered justi- fied because of the few number of tests on which most of the re- sistance periods are based, several of them being derived from single tests, the results of which it is necessary to assume fall within the higher rather than the average or lower range of possible variation. (e) Resistance to Water Application With reference to fire and water exposure, the results are regarded as satisfactory if the applied load was safely sustained during the fire and water periods, and in the case of the protected columns, if the covering remained in place, after a 2-min. period of water application to such extent as to prevent early failure of the column on being again exposed to fire, precluding in all cases complete removal of the covering from any section of the column. (f) Size Limitations The derived fire resistance periods apply most nearly to col- umns of approximately the same size as those tested and should be applied with considerable caution in connection with smaller columns. Minimum areas with relation to the derived periods are given in Table 46. The studies made on effect of size indicate that the test results can be applied with safety to columns of larger size than those tested. BASIS OF DERIVATION 215 (g) Application to Building Conditions It is believed that the types of columns and protections tested can be applied with confidence in building construction as being able to resist fires of duration equal to the resistance periods here- with derived for the respective types, provided that reasonable care is taken to identify the material used and to secure a fair grade of workmanship. In constructing the coverings and columns, a consistent effort was made to introduce methods and conditions similar to those incident with building construction, and it is thought that the col- umns as tested are fairly representative of the average attained in good building practice. The columns tested covered a wide range in material and shape of section and each class of covering material was represented by its main varieties in common use. In applying the results broadly, some difficulty may be experienced due to difference in materials of the same kind or name as occurring in different localities, relative to which some explanatory notes and cautions are given in deriv- ing fire resistance periods with the respective materials. It is be- lieved that if the materials are properly identified, and classed with the corresponding materials employed in the column tests, the resulting difference in fire resisting properties will not be large, provided the mineral constituents and impurities are within the limits hereafter given. In the column, tests, the temperatures indicated by the pyro- meters, while corresponding on the average quite closely with those on the reference curve (compare reference curve and average curve, Fig. 39), were lower than that of the furnace gases surrounding them, due mainly to radiant heat interchange between the pyrometer and the colder furnace enclosure. The difference was determined to be as large as 150 C. for points near the beginning of the test, with gradual decrease to less than 50 C. at the end of an 8-hr, run (p. 115-120, Fig. 41). The high intensity of the furnace ex- posure to which the columns were subjected, can be taken as com- pensating to some extent for differences in material incident with broad application of the test results, and give assurance that such application is justified where the variance from the materials tested is not too large. 216 FIRE RESISTANCE PERIODS The loads applied to the columns during the test come within the higher range of normal working loads, and it is believed that the loads imposed on columns under fire conditions in buildings will seldom be much larger, either as caused by floor loads or by unequal expansion of adjacent columns during the fire. The column coverings had a full and firm bearing at the base of the column and were full and continuous at the top, and there- fore took portions of the applied load proportionate to their relative area and rigidity with respect to the structural section. Coverings as applied in buildings will sometimes have less firm bearing at the base and be less continuous at the top, due to obstructions to proper placement offered by the floor members. This difference in ability to carry load will affect chiefly the concrete protections and fillings, since the other types have little load carrying capacity near failure. With concrete protections it will affect only the period between maximum expansion and failure, the metal section assuming almost all of the load during the preceding period, due to its higher rate of expansion. Concrete will develop bond within a relatively short distance with a number of forms of metal section, making the cov^- ering in effect a part of the column in the middle portion of its length, even if it is not fully continuous at the ends. It is therefore apparent that the difference between the test condition and the con- dition of possible occurrence in buildings is not large as far as it concerns the fire resistance of the column, and considering the rela- tively smaller variations due to other causes generally incident with concrete protections, it can be taken as sufficiently allowed for in the reduction of the time to failure adopted for deriving fire re- sistance periods. The fire resistance afforded by columns is based on the time to failure rather than the useful limit because the former is def- initely determined by the test procedure. It is deemed, however, that with the interpretation of test results given above, the pro- tection given by the columns and coverings will generally be suf- ficient to prevent permanent damage of such extent as to require repair or replacement after fire exposures corresponding in duration to the pertaining resistance periods. Only where very severe local fire exposure is coincident with other unfavorable conditions, such as inferior material and workmanship, will the resistance of the column beyond its useful limit be likely to be developed. DERIVATION FROM TEST RESULTS 217 2. DERIVATION OF FIRE RESISTANCE PERIODS In deriving the resistance periods the method described in par. la of this section is followed, giving consideration also to effects of water application as explained in par. le. Interpolations for cov- ering thicknesses intermediate between those tested are made where justified by the test results. Limited extension of results to materials not included in the particular combination considered, but giving similar test characteristics in other related tests of this scries, is made in the 'case of concrete and hollow clay tile pro- tections (Table 46, p. 211-213). , For columns with square or rectangular protections all portions of the main members are assumed covered by not less than the nominal thickness of material specified. With round coverings, on columns of square or rectangular outline, the distance from the surface to the edge of the main column members may be reduced somewhat, provided the resulting cross-sectional area is not less than that of a square or rectangular protection of the same nominal thickness. Details having relatively large areas, such as lattice bars and splice plates need to be covered by the nominal thickness specified. For smaller areas, as of rivets and extreme edges of bracket or sup- porting angles, the covering thickness may be reduced to one inch. Where partitions or pipe enclosures are supported by column coverings, the connection should be made so that the stability of the covering is not affected by buckling or failure of the sup- ported walls. Pipes should not be placed within the thickness of covering required for the given resistance periods nor incor- porated in the covering in such manner as to dislodge any essential portion thereof by expansion or buckling incident with normal use or with fire conditions. (a) Unprotected Structural Steel Columns As based on Test Nos. 1 to 8, and with not less than the mini- mum metal thickness and area of section given in Table 46, un- protected structural steel columns give 10-minute fire resistance. The low degree of resistance afforded indicates unsuitability for use where fires of any appreciable degree of intensity and dura- tion are possible. 218 FIRE RESISTANCE PERIODS (b) Partly Protected Structural Steel Columns The protection consists of concrete that fills the interior and reentrant portions to the outside of the extreme metal on the main members. Except on the open sides of latticed columns, the concrete is secured with horizontal and vertical metal ties. (1) Solid Section Columns. Structural steel columns of solid rolled or riveted section, whose reentrant portions are filled with concrete made with any of the aggregates included in the present series of tests, except highly siliceous sand* and gravel, mixed in proportion of 1 part Portland cement to not more than 8 parts fine and coarse aggregates combined, and with combined area of steel and concrete not less than 35 sq. in., give one-half hour fire resistance. 'Similar columns filled in the same manner with lime- stone, calcareous gravel or trap rock concrete, and with area of filled column not less than 60 sq. in., give three-fourths hour fire resistance. The one-half hour period is based on Test Nos. 15, 16 and 17, and the three-fourths hour period on Test Nos. 14, 20 and 21. (2) Open Latticed Section. Structural steel columns of open latticed section, with the interior and reentrant portions filled with concrete of proportion 1 part Portland cement to not more than 6 parts fine and coarse aggregates combined, and with total area of not less than 120 sq. in., give 2-hour fire resistance if concrete is made with trap rock aggregate and 3^-hour fire resistance if lime- stone aggregate is used. The above conclusions are based on Test Nos. 18 and 22, the higher resistance over the solid section columns being due to ab- sence of large areas of exposed metal. It is essential to use concrete that is not subject to cracking or spalling since the covering on parts of the main members is usually little more than one inch thick and not tied. (c) Structural Steel Columns with Plaster on Metal Lath Protections The plaster may be applied on either expanded metal or woven wire lath. The layer thickness is measured from the inner line of the lath. The proportion of the plaster considered is 1 part Port- land cement to not more than 2y 2 parts medium coarse sand, with lime added equal to Vio of the cement volume. The periods derived are based on Test Nos. 23 to 26, and 110, in which the above pro- portion was used. The effect of varying the lime content is other- wise not known. DERIVATION FROM TEST RESULTS 219 (1) Single Layer Protection. Structural steel columns pro- tected by a layer of Portland cement plaster 1 in. thick, applied on metal lath give three-fourths hour fire resistance. (2) Double Layer Protection. Structural steel columns pro- tected by two layers of Portland cement plaster each J^ in. thick with J^-in. airspace between layers, give \y 2 hour fire resistance. (d) Concrete Protections on Structural Steel Columns The protections, preferably placed without construction joints, should extend through the floors, where the floor filling is of other material than concrete, and be tied w r ith iron or steel wires or mesh, embedded in the covering and extending to within about one inch from its surface, the ties to be equivalent to not less than a No. 5 (B. and S. gauge) steel wire wound spirally on a pitch of 8 in. The proportion of concrete mixture taken is 1 volume part Portland cement to 6 parts fine and coarse aggregates combined, 94 Ib. of the cement being taken as its weight per cu. ft. The effect of reducing the cement content of the mixture was not definitely deter- mined in the tests although some reduction in fire resistance was noted as between the 1 : 6 and the 1 : 8 proportion, estimated as equivalent to reductions in the resistance periods of not more than one-half hour for periods up to three hours and possibly as much as one hour for the longer resistance periods. Limitations relative to size are given in Table 46 (p. 211). For columns of dimensions much larger than the given minimum, the periods apply with a considerable margin of safety. (1) Siliceous Gravel Concrete Protection. Structural steel columns covered with a 2-in. thickness of concrete made with gravel aggregate of high silica content, give one-hour fire resistance, and with similar 4-in. protections give 2%-hour fire resistance. Since the failure of coverings of this type of concrete is de- pendent on stability of portions thereof, no adequate basis is pres- ent for estimating of the value of the resistance period for thick- nesses intermediate between two inches and four inches. The periods are based on Test Nos. 39 and 45 where the ag- gregate consisted mainly of chert grains and pebbles. Since this form of silica develops as great or greater disruptive effects on ex- posure to fire as quartz, flint and related minerals, the derived protection periods apply generally where concrete made with all common forms of siliceous aggregates is used. 220 FIRE RESISTANCE PERIODS (2) Granite, Sandstone or Hard Coal Cinder Concrete Pro- tection. Structural steel columns covered with 2-in. protections of granite, sandstone or hard coal cinder concrete, give 2^-hour fire resistance, with 3-in. coverings give 3^-hour fire resistance, and with 4-in. coverings give 5-hour fire resistance. Tests were made of 2-in. coverings of concrete made with sand- stone and cinder (Nos. 31, 32, 32A, 43, 44 and 104), and in the 4-in. thickness, with granite as the coarse aggregate (Test Nos. 34, 34A and 103). The extension of the results with sandstone and cinder concrete to cover thicknesses heavier than 2 in., and of gran- ite concrete to cover thicknesses lower than 4 in., is based on rela- tive effectiveness with respect to trap rock concrete in coverings (Test Nos. 29, 36 and 37) of comparable thickness. The granite used in the concrete of the column coverings tested, contained 35 percent quartz and about 60 percent feldspars, chiefly orthoclase (Table 20, p. 360), the size of crystals ranging from .03 in. to .35 in. The range in quartz content of granites is generally from 20 to 40 percent with extremes from 5 to 50 percent. In crystal size the general range is from .02 in. to .40 in., with extremes up to 2J^ in. It appears therefore that the granite tested came within the higher range in quartz content and had crystals of average size. To what extent changes in mineral composition and crystal size of granite affect the fire resistive properties of concrete made with it is not known, although it would be expected that those of lower quartz content will be the least subject to destructive fire effects. The B'erea sandstone used in these tests was a silica cemented stone of average hardness, consisting almost wholly of subangular grains of quartz. Some disintegration from heat due to loss of ce- menting properties was noted but not enough to affect the fire re- sisting properties, the principal fire effects being cracking and dis- lodgement of relatively large masses, induced presumably by the high quartz content. Among sandstone used as concrete aggregate, quartzite has all pore spaces filled with silica cement, resulting in a hard homo- geneous quartz mass. Flame tests made on small specimens of the stone do not indicate any greater disruptive effects than those in- cident with similar tests of other sandstones. Silica cemented sandstones range in hardness from compacted sand to a condition approaching quartzite, all being of high silica content, usually over 95 percent. The softer grades are generally eliminated from use as concrete aggregate on the score of deficient strength and hardness. DERIVATION FROM TEST RESULTS 221 The lime cemented sandstones range in mineral composition from nearly pure sandstone to sandy limestones carrying only small amounts of silica. The iron (limonite) and clay cemented sand- stones, of which the brownstones are representative, carry vari- able amounts of feldspar and mica, the range in free quartz content being from 50 to 90 percent. The bluestones of New York, Pennsyl- vania and West Virginia contain from 20 to 60 percent quartz, the other minerals being mainly feldspar and hornblende. While not possible to predict fully the behavior of combina- tions of minerals on exposure to fire, it is probable that the addition of calcareous, clayey or felspathic minerals to quartz to form the sandstones noted above, will decrease rather than increase the cracking incident with fire exposure of purer forms of the rock The hard coal -cinder contained about ten percent unburned coal and five percent ash, and to obtain comparable results these per- centages should not be greatly exceeded. (3) Trap Rock Concrete Protection. Structural steel col- umns protected by 2-in. coverings of trap rock concrete give 3-hour fire resistance, with 3-in. coverings give 4-hour fire resistance, and with 4-in. coverings give 5-hour fire resistance (Test Nos. 29, 36, 37, 40, 101, 103 and 104). The periods for the 2-in. and 4-in. coverings were derived directly from the test results, and the period for the 3-in. thick- ness taken as their average. Trap rock is a dark colored fine grained igneous rock that does not vary greatly in mineral composition, and carries at most only a trace of quartz (Table 20). The term does not include the hard sandstones known under the same name in some localities. (4) Limestone or Calcareous Gravel Concrete Protection. Structural steel columns protected by 2-in. coverings of limestone or calcareous gravel concrete give 4-hour fire resistance, with 3-in. coverings, give 6-hour fire resistance, and with 4-in. coverings give 8-hour fire resistance. Tests were made of 2-in. coverings of limestones and calcareous gravel concrete (Test Nos. 28, 28A, 30, 38, 101, 102 and 104) and of 4-in. coverings of 1 :6 and 1 :8 limestone concrete (Test Nos. 33, 33A, 35, 41, 42 and 103). The period for the 2-in. thickness was derived di- rectly from the test results. The columns with the 4-in. covering all withstood the 8-hr, fire test and while hot sustained such large addi- tional loads as to justify the conclusion that in the lower range of results with comparably protected columns, the working load will be sustained during an 8-hr, fire period. 222 FIRE RESISTANCE PERIODS The limestone and calcareous gravel of the tests were dolomitic and contained about five percent of clayey impurities (Table 20, p. 360). It is thought that the results apply without modification where high calcium limestone or gravel of nearly the same purity is used. The silica impurities in limestone occur as free silica (quartz, chert, flint and opal), and silica combined in clay and other silicates. Most limestones carry from 5 to 10 percent of combined clayey impurities but not many have more than 10 percent of free silica, and within the limits given these impurities are not deemed objectionable for stone or clean gravel used as concrete aggregate in fire resistive con- struction. Some limestones contain higher percentages of free silica and particularly the waste from lime kiln and cement plant quarries is likely to be high in chert. Gravels in the glaciated area, which includes nearly all of the territory north of the Missouri and Ohio rivers, New England, New York, northern Pennsylvania and northern New Jersey, may con- tain material from any point to the northward and formed under the most diverse conditions will vary greatly in mineral composition both vertically and horizontally. This also applies to the gravels of the Great Lakes and the ocean gravels as far south as New York. If the superior fire resistive qualities of concrete made with cal- careous gravel is to be assured, or the highly siliceous gravel avoided, it is necessary to identify the material in each bank by means of suitable chemical or mineralogical analyses at successive times as the development proceeds. Outside of the glaciated area, the river and shore gravels are more uniform, although varying with changes in the rock forma- tions of the drainage area or headlands. The calcareous content of the sands (Fox River and Joliet) used in combination with the limestone and calcareous gravel was higher than the combined quartz and chert content (Table 20). While all sands are likely to contain considerable silica, and the extent of their influence on the thermal properties of concrete made with them is not known, it is thought best to avoid using highly siliceous sands in combination with limestone and calcareous gravel where the full fire resistive value of the concrete is to be utilized. As used with the other coarse concrete aggregates, the mineral composition of the sand is of minor importance, provided it meets the common requirements for a good concrete sand. The sand in a given deposit is generally more uniform in composition than the larger sized material. DERIVATION FROM TEST RESULTS 223 (e) Hollow Clay Tile Protections on Structural Steel Columns The tile is assumed to be applied in courses about 12 in. high with fairly full horizontal and vertical mortar joints between the tile units. The mortar should also fill the space between the tile and column flanges except where it is filled with concrete. The pro- portion of mortar used in the tests was 1 volume part Portland cement, to 1 of stiff slaked lime, and 4 of fine sand. While the influence of mortar proportion on the effectiveness of the covering is not definitely known, the test results are not fully applicable unless mortar having about the same content of cementing materials as that given above is used, and particularly the Portland cement should not be reduced below the proportion given. As an aid in assigning fire resistance periods for combinations of tile and de- tails of application not included in the tests, it can be stated that in the tests the semi-fire clay tile burnt to medium hardness dis- played the best fire resistive properties, followed in order by tile of hard burnt semi-fire clay, of surface clay and of shale. The coverings tested were generally tied with one No. 12 (B. & S gauge) iron or steel wire placed tightly around the outside of each course, or by strips of woven wire of ^g-m- mesh, placed in the horizontal joints and lapping at the corners. The latter method is considered superior to the outside wire ties and can be substituted for them where desired. The difference in effectiveness of the two methods is not considered so large as to justify requiring the mesh except for tile subject to severe disruptive effects on exposure to fire and where the higher resistance periods are to be attained. Other forms of interior ties may be used if equivalent in effect to the wire mesh. In assigning fire resistance periods to given protections, con- sideration is given to the effect of area of solid material in the cross section of the covered column, having reference to the minimum values given in Table 46 (p. 212). The proportion of mixture used for the concrete filling was 1 part Portland cement to not more than 8 parts fine and coarse aggregates combined, the filling being placed after the tile was set. Any aggregate used in these tests may be employed except highly siliceous gravel. 224 FIRE RESISTANCE PERIODS (1) Unfilled Protection. Structural steel columns with hol- low clay protections of 2-in., 3-in. or 4-in. semi-fire clay tile of medium hardness, tied with outside wire ties, give one hour fire re- sistance. This period is based on results of fire test Nos. 48 and 49 taken together with fire and water tests Nos. 105 and 107. The tile in these tests developed fewer disruptive effects on exposure to fire than any other kind tested. Tile more sensitive to abrupt tem- perature change is not adapted for use in unfilled protections, as the cracking and spalling resulting after a short fire exposure al- lows the heat to readily reach the steel, also on application of water, parts of the impaired covering are liable to be carried away, leaving the metal unprotected against a possible recurring fire. The use of unfilled protections should generally be avoided as the filling materially increases their stability and insulating value. (2) Shale or Surface Clay Tile Protection with Concrete Filling Reentrant Spaces. Structural steel columns with hollow clay tile protections of 2-in., 3-in. or 4-in. shale or surface clay tile, tied with outside wires, and with concrete filling the reentrant spaces between tile and column web, give one-hour fire resistance (Test Nos. 50, 50A, 52, 53 and 106). Similar protections of 3-in. or 4-in. surface clay tile with heavy shells and webs give IJ^-hour fire resistance (Test Nos. 51 and 51A). (3) Semi-fire Clay or Surface Clay Tile Protection with Full Concrete Filling. Structural steel columns with hollow tile pro- tections of the given types of clay, set 1 in. away from the flanges and edges, with concrete filling all spaces between the steel and the tile, give 2-hour fire resistance where outside wire ties are used (Test Nos. 54, 55 and 57), and with wire mesh in the hori- zontal joints give 2J^-hour fire resistance (Test Nos. 56 and 77). The thickness of tile, using outside wire ties may be either 2, 3 or 4 in. With the wire mesh the thickness should preferably be not less than three inches to allow ties of sufficient width to be used. (4) Double 2-in. Tile Protection. Structural steel columns with protections of two layers of 2-in. surface clay tile, and with the space between the inner layer and the column filled with tile set in place, give 3-hour fire resistance when the covering is bonded with wire mesh in the horizontal joints and one-hour fire resistance if tied with outside wire ties. The periods are based on Test Nos. 58 and 59, which indicated a marked difference in results due to the method of tying the sur- DERIVATION FROM TEST RESULTS 225 face clay tile applied in the given type of protection. Concrete filling may be substituted for the tile filling if desired. (f) Brick Protections The fire resistance periods are derived from the results of Test Nos. 68 and 69. The same qualifications relative to mortar apply as for the hollow clay tile protections, as also the size limitations given in Table 46 (p. 212). Structural steel columns thus protected with common surface clay brick, set on edge and end outside of the flanges and edges and filling the whole space to the steel, give one-hour fire resistance, and with brick laid flat on side to form a solid protection of about four inch thickness, 5-hour fire resistance is developed. (g) Gypsum Block Protections The derived resistance periods apply to columns covered with solid gypsum block set in mortar of proportion, 1 part calcined gypsum to 3 parts fine sand, the blocks being bonded with strips of corrugated iron or wire mesh placed in the horizontal joints over all vertical joints. The space between the outer blocks and column can be filled with gypsum blocks set in place or with poured filling consisting of calcined gypsum, broken gypsum blocks and sand, mixed with enough water to enable proper placement. Structural steel columns with protections of 2-in. solid gypsum blocks placed according to the above details give l^-hour fire re- sistance (Test Nos. 65, 66 and 108), and with similar protections of 4-in. solid gypsum blocks give 3^-hour fire resistance (Test Nos. 64, 67. 67 A and 109). Interpolation between the two thicknesses appears justified, the protection made with the 3-in. solid block giving accordingly a resistance period of 2*/2 hours. The area limitations given in Table 46 (p. 212) apply less rigidly to gypsum block protection than to most other types, because the failure is induced by loss of stability of the blocks after a given fire exposure and not to normal transmission of heat through the covering. (h) Cast Iron Columns (1) Unprotected Columns. With the minimum area and wall thickness given in Table 46 (p. 212), unprotected cast iron columns give 20-minute fire resistance. The fire tests (Nos. 9, 10 and 10A) were made on round col- umns of about 24-in. wall thickness, and gave uniform results, al- though they were not sufficient in number to develop possible vari- ations due to quality of metal and differences in wall thickness. 226 FIRE RESISTANCE PERIODS The fire and water tests, while inducing large permanent deflec- tions did not cause the columns to lose ability to sustain working loads. Filling the interior with concrete (Test No. 11) gives an in- crease in resistance of 10 min. or a total period of one-half hour. (2) Plaster on Metal Lath Protection.-r-A single heavy layer of Portland cement plaster of 1^-in. average thickness applied on high-ribbed metal lath to round cast iron columns gives a fire resistance of 2 hours (Test No. 27). The same proportion of plaster applies as given above under (c) for protections on steel columns. To attain the required average layer thickness the surface of the covering will extend about two inches outside of the metal, on account of voids inside of the lath. (3) Concrete Protection. Round cast iron columns with 2-in. protections of trap rock, granite or hard coal cinder concrete, give 2-hour fire resistance. The period is based on Test No. 47 where cinder concrete was used. Extension to include concrete made with the other aggre- gates is made because of characteristics similar to cinder concrete developed by them in other tests of concrete protection. Limestone and calcareous gravel concrete would on the same basis give longer resistance periods. The proportion of the concrete can be taken as 1 part Portland cement to not over 7 parts aggregate. Relatively small sized aggregates need to be used, to enable good placement of the covering, and with some aggregates it may be necessary to increase the thickness of the covering to secure this result. The ties, equivalent to not less than No. 5 (B. & S. gauge) steel wire on 8-in. vertical pitch, are to be supported about one inch away from the column. (4) Hollow Clay Tile Protection. Cast iron columns covered with 2-in. curved porous semi-fire clay tile, with 34 in. of mortar between tile and column and tied with outside wire ties, give 2-hour fire resistance (Test Nos. 62 and 63). The same details of application can be taken to hold as for hollow tile protections on structural steel columns. (i) Unprotected Pipe Columns "Unprotected columns consisting of steel or wrought iron pipes, not smaller than the standard 6-in. pipe size, with filling of concrete, give 25-minute fire resistance. Pipe columns not smaller than the 7-in. standard pipe size, filled with concrete and reinforced in the fill with structural shapes give three-fourths hour fire resistance. DERIVATION UROM TEST RESULTS 227 The proportion of the concrete rilling is taken to be one part Portland cement to not more than 4^ parts fine and coarse aggre- gates combined (Ta'ble 46, p. 213). The conclusions relative to pipe columns are based on Test Nos. 12 and 13, made, respectively, on a 7-in. plain pipe column and on an 8-in. reinforced pipe column, both being standard new steel pipes with wall thickness of about -& inch. Extension of the result with- the former to make it applicable to the 6-in. pipe size, and of the latter to apply to the 7-in. size, appear justified. (j) Reinforced Concrete Columns The proportion of the concrete for which the derived periods hold is 1 part Portland cement to 6 parts fine and coarse aggre- gates combined, the coarse aggregates being trap rock or lime- stone (cf. Sec. XII, par. 3i, p. 206). The same considerations relative to possible variations in the aggregate hold as for concrete protection. The columns may be round or square and reinforced with verti- cal bars held by lateral ties spaced not farther apart than 12 in., or by vertical bars and spirally wound wire hooping, all reinforce- ments to be covered by not less than 2 in. of concrete placed in- tegrally with the structural portion of the column. Under these conditions, reinforced concrete columns made with limestone or highly calcareous gravel aggregate can be taken as giving 8-hour fire resistance (Test Nos. 70, 72, 74, 111 and 112),, and made with trap rock aggregate, 5-hour fire resistance (Test Nos. 71, 73, 75 and 113) (Table 46, p. 213). The limestone concrete columns withstood the 8-hr, fire test and while hot, sustained ultimate loads of from a little less than twice to nearly three times the load sustained during the 8-hr. period. This gives reasonable assurance that all similarly con- structed columns, using a properly identified limestone aggregate, will sustain working load until the end of an 8-hr, fire period, taking into account all probable variations. Calcareous gravel can be used in place of limestone if the free silica and other impurities are within the limits given in par. (d4), (p. 222). Two of the trap rock concrete columns failed during the 8-hr. period and the other withstood the 8-hr, fire test and about 25 per- cent additional load at the end of this period. The fire resistance period is therefore almost fully determinate on the basis of test duration. 228 FIRE RESISTANCE PERIODS (k) Timber Columns With unprotected or protected timber columns having exposed cast iron or steel caps, the resistance to fire is limited by failure at the bearings before the full resistance of the timber has been de- veloped elsewhere (cf. Sec. XII, p. 181 and 208). The resistance periods apply most fully to the species tested, longleaf pine and Douglas fir, although with failure occurring at the bearings, the species of timber is not a governing consideration. (1) Unprotected Timber Columns. As based on Test Nos. 79, 81, 82 and 83. unprotected timber columns with exposed cast iron or steel caps give 25-minute fire resistance. (2) Protected Timber Columns. Timber columns having cast iron or steel caps, and protected by a layer of gypsum wall board y% in. thick, give three-fourths hour fire resistance (Test No. 80), 2nd protected by 1-in. layer of Portland cement plaster on metal lath with a ^-in. airspace between the timber and the plaster layer, give 1J/2 hour fire resistance (Test No. 78). The protections are assumed to cover all exposed metal of the caps as well as the timber. The proportion of the Portland cement plaster should be taken the same as given for plaster coverings on steel columns (Table 46, p. 211-213). Protections on timber columns should be applied with caution on account of possible unfavorable effects upon the timber in point of susceptibility to decay (cf. Sec. XII, p. 209). 3. CONDITIONS GOVERNING FIRE DURATION IN BUILDINGS. The intensity and duration of building fires depend upon the character and amount of combustible material in the building con- struction itself and in the building contents. The latter will be determined in a general way by the occupancy. Office and residence occupancies generally support fires of shorter duration than manu- facturing, merchandising or storage. The possible duration of fire is also determined to some extent by the floor load for which the building is designed, since it limits the amount of material subject to fire. The effective fire duration as far as it concerns a given building member pertains only to the duration of the combustion taking place near enough to it to impart temperatures sufficiently high to cause failure under its supported load. This is not necessarily the same CONDITIONS GOVERNING FIRE DURATION IN BUILDINGS 229 as the total duration of the fire within the building or within a subdivision thereof such as a building story. It is necessary to assume maximum probable conditions both with regard to building contents and air supply, as considered with respect to intensity and duration of a possible fire. Compensations and adjustments between intensity and duration may be necessary under some conditions in order to approximate a fire duration having intensity equivalent to that of the exposure in the fire test. Limitation of the degree of resistance to be developed to the requirements of present or im- mediate future occupancy is generally not justified unless the build- ing, its location or use is such that no change to a use involving a more severe fire condition is probable. While it is outside of the scope of the present report to at- tempt the determination of probable fire duration for various types of buildings and occupancies, it is a step in the application of the test results that will require careful consideration. The fire re- sistance periods were derived under exacting conditions in point of test columns, test conditions and interpretation of results, and the types of columns and protections to which they pertain are deemed to be fully adequate for resisting building fires of cor- responding duration. APPENDIX A VIEWS OF COLUMNS BEFORE AND AFTER FIRE TEST Fig. Test No. No. Protection Page 58 1 to 5 Unprotected Structural Steel Columns 231 59 6 to 8 Unprotected Structural Steel Columns 232 60 9 to 13 Unprotected Cast Iron and Pipe Columns 233 61 14 to 18 Partly Protected Structural Steel Columns... 234 62 19 to 22 Partly Protected Structural Steel Columns... 235 63 23 to 27 Plaster on Metal Lath Protections 236 64 28A to 31 Concrete Protections 237 65 32 to 34A Concrete Protections 238 66 35 to 39, 45 Concrete Protections 239 67 40 to 44, 46, 47 Concrete Protections 240 68 48, 49, 50 Clay Tile Protections 241 69 50A, 51, 51A Clay Tile Protections 242 70 52, 53, 54 Clay Tile Protections 243 71 55 to 58 Clay Tile Protections 244 72 59, 60 Clay Tile Protections 245 61, 62, .63 Clay Tile Protections 246 74 64, 65, 66 Gypsum Block Protections 247 75 67, 67A Gypsum Block Protections 248 76 68, 69 Brick Protections 249 76 70 Reinforced Concrete Column 249 77 71 to 75 Reinforced Concrete Columns 250 78 76, 77 Plastered Clay Tile Protections 251 79 78 Longleaf Pine Column, Protected 252 80 79 Longleaf Pine Column, Unprotected 253 81 80 Longleaf Pine Column, Protected 254 81 81 Longleaf Pine Column, Unprotected 254 82 82,83 Douglas Fir Columns, Unprotected 255 VIEWS OF COLUMNS BEFORE AND AFTER FIRE AND WATER TEST 83 101, 102, 103 Concrete Protections 256 84 104 % Concrete Protection 257 84 105 Clay Tile Protection 257 85 106, 107 Clay Tile Protections 258 86 108, 109 Gypsum Block Protections 259 87 110 Plaster on Metal Lath Protection 260 88 111, 112 Reinforced Concrete Columns 261 89 113 Reinforced Concrete Column 262 89 114, 115 Cast Iron Columns 262 230 COLUMNS BEFORE AND AFTER FIRE TEST 231 232 APPENDIX A COLUMNS BEFORE AND AFTER FIRE TEST 233 234 APPENDIX A I ! f J * 5 I oc 'I BC * '/ i 1 is COLUMNS BEFORE AND AFTER FIRE TEST 235 236 APPENDIX A ]. ! * I 5 * J"*-' e^ *? 5 J '-S 8 ^ ^) * I j$ 1 bi \ f . fe COLUMNS BEFORE AND AFTER FIRE TEST 237 ft-- i r ; 238 APPENDIX A COLUMNS BEFORE AND AFTER FIRE TEST 239 Iff- I 240 APPENDIX A ^ f 1 ? l * T 'M I a- COLUMNS BEFORE AND AFTER FIRE TES, 242 APPENDIX A COLUMNS BEFORE AND AFTER FIRE TEST 243 244 APPENDIX A COLUMNS BEFORE AND AFTER FIRE TEST 245 246 APPENDIX A *- t-5 3 1 I o x^ ! \ E fO 5 ^ c &0 j E COLUMNS BEFORE AND AFTER FIRE TEST 247 fi o 248 APPENDIX A I fe I Q s in ~ C3 fl <5o < >0 B k 3 .Z ^ I ^ 5 COLUMNS BEFORE AND AFTER FIRE TEST 249 \ I o Is ,1 I I 11 s M I b S s tt; ?1 TEMPERATURE IN DEGREES CENTIGRADE TIME-TEMPERATURE CURVES 267 TEMPERATURE IN DEGREES 88888 P QO FAHRENHEIT 8 TEMPERATURE IN DEGREES CENTIGRADE 268 APPENDIX B TEMPERATURE IN DEGREES FAHRENHEIT oooooooooooooooo 5 1 1 1 f 1 1 I 1 1 1 8 f ? 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Cl S^ ^ v . , X, X *4 fy. (/) X X ^ ^ . k V \ x^ v ^4 '** ' <^ s JB ^c ^ ts^ 5 ^0 N^ "^t "* f/ >^ * \ \ ^, ^~^ -o * ^A > X !Sx / v 3 I ^ ^ 2< v- - p*- . ^ ~. MI" x \ ^ \ *, ^ \ *> _ X x X ^ CM X x * **> ^ X 2 z c <(, s ^ ^< w fe r /*. S "^ a /^ ^ 2 i- / x \\ ^y 1 ^ v \ > X; 9 V, i i i i i i i i J i TEMPERATURE \N DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN tOOOOO DEFORMATION AND AVERAGE TEMPERATURE CURVES 325 TEMPERATURE IN DEGREES FAHRENHEIT 222 O 22 O 22 QOOOOOOOOOOO oaor-<0iZ>3ncM- -tr -r H ^_ fe t=* 4-T t] -h -tr -t t H O \ ^, ^^ sf X ^ fi\ si \ v y CVJ ^ s^ \ H* CM ^ o ^ \ ^*> o z r X \ '*i> h- , 'o, "S ^^ K! " *ju N s i Of ^ ^ ^s y V >^ *> y ^7 -^ ^J V 1 c^. 5 s^ ^ ^ i 1 * i to 'DC O O *^ I $ CM Z 5 w ^r s ^o ^ "^^; =5^. >i Q "^ ^ =^; k^ " *X3 * bn N S k N s* 2 *\ D V - f in | CM UJ * c |/ f *=5; N 'Ik' 7 J' ^ ** b , ^ ! 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TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 1OOOOO DEFORMATION AND AVERAGE TEMPERATURE CURVES 337 TEMPERATURE IN DEGREES FAHRENHEIT H-l-f 188888888! -t -3 t r 1 ftl [ 1 | T -t i 7 6 e protection, Test No. 4 ^ \ \ \ \l L 1 \ I \ K t \ \ \ V \ \ \ s < tone concret \ V V \ > 3 v: V ^i \ \ j A ^ w J ^t- * 7 it \\ 4 j. 5 . ^ i i ( ^ I \ i o 1 \ A i A 1 \\ iS3 3 TIME II deformation, Jr % M \ w % ^ * Ahr SK \\ u e 1 2 \\ ' ' I \ 1 %> | :| I \ k ^ vO bfl r> ;~* \, \ 1 ! 1 i \ \ I \ I I C ) i i i " < : 8 5 t Bi TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 1OOOOO 338 APPENDIX C TEMPERATURE IN DEGREES FAHRENHEIT 88888888888 -oa>io3<9r O $ ^^ J) v^ ; z .- s ^. ifj f , fe *r *^N >> ^ LJ '^t^ *V X -^ ^ **!. h- 1 ^ 7 N ^ j N, / i> v /7 ^-" ^ \ / \ \ -s / A K^ ? -*> (M X^ ^ ^ ^?- in ^x x g \v, ^5 . *> *, ?* s ^ V \ ;j *tr In [\ V fl S S > \ *v UJ ^ v *^x^ . \ ^ * ^, 4, X; hSs '^/j V *v ^ r^. * (L X ^ *0~ V \ ^ ^ k o \ \ V } V ^> V T^ > 1 SE 4 X ''< ^ \ s s 4 g v n ^. *> s^ ! L. " , ^\ ^Ql i *< h v ''S ^ K ^ s: h ^. " |, _^ ^ 3 / 9 *aa<- -M TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 100000 11 3 bib 340 APPENDIX C TEMPERATURE IN DEGREES FAHRENHEIT foooooooooooo |||ii?s? -r -r i I f; 1 ~r r 1 ^ C4 O CM ^J -* N,, *r* ^*- \ ^*- --^ \ ^ ^x V J \\ * V' \ > c y L s <, ^ s . M (A * \ ^ o ** \ z ^ XN S *-J I:, ** . s \ Hi \ s i- ** \ s \ s, ^ \ V ^\, s \ \ \ 1 / ^v ^ \ s s^ \ s \ ^ X ^ \ A ^ ^ ^ ^ \ o 4 f s \ z J 'f) s ^0 \ K (0 *t v^ ^4 S ^ S s *s ^* J- ^ V \ *+ > A s \ \ p \ I 1 * s 8 " s TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 10OOOO sr DEFORMATION AND AVERAGE TEMPERATURE CURVBS 341 TEMPERATURE IN DEGREES FAHRENHEIT II -tr-tr | 1 III 88S88 -co 8 A ^ u 7, *^: <> o ^ | TEMPERATURE W DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 1OOOOO Hi ! I! 2 v* 3 E^ x> k, % % ! & ^ 2 bb " 342 APPENDIX C TEMPERATURE IN DEGREES FAHRENHEIT 8888888888888 2!;;oa>a>N3, / \ H> \ \ ^ 0, X \ ^ ~ VJ fn *0 'x. \ ^ 5 "-- "^ \ 5 z '\ \ \ 1 j- ^0 x \ "^ (2 ^ , - " *\ ^s l ^l ^ H N ^ ^ ^ sK N \ 3 1 ] T^ "~*-s A i Wl^ , = _ - i_ -^ = . , ' s /^ \ / \ / \ y \ V \ \^ \ s> P ix \ /t co 3 s *l ^ y V. ^ XT s \ i- J > \ X ^o. \ \ x V ^ j_ * 6 v s N ^ 'h 5 \. \ \ \ \ *b s ^ * \ V S \ \ ^ \ ^ 3 i 8 8 i CO K 8|88888 ' TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 1OOOOO \ c 1 s (/) * Id g 5 ^ bfi . tf 344 APPENDIX C TEMPERATURE IN DEGREES FAHRENHEIT I I 1 1 i i i 1 "^ -* \ ,x \ 2 ^ \ / \ / ^ \ K 5 'ft ^ 5 ( s 'j s ^ "fl i \ \ ^ 3 ^ 1 ^> c ^> \ ^ '0 \. ^, ^ \ \ t ^_ 3 q \ N ^4 z A / s \ LJ \ 1* \ V \\ \ \ \> \ 3 \ \ A \ \ 1 g i 1 I " 5 8 5 TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 1OOOOO DEFORMATION AND AVERAGE TEMPERATURE CURVBI 345 TEMPERATURE IN DEGREES FAHRENHEIT 1 838 8 ! TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 10OOOO 346 APPENDIX C TEMPERATURE IN DEGREES FAHRENHEIT \ \\ 2 -2- y P i TEMPERATURE IN DEGREES CENTIGRADE UNIT DEFORMATION .PARTS IN 100000 DEFORMATION AND AVERAGE TEMPERATURE CURVES 347 TEMPERATURE IN DEGREES FAHRENHEIT 222222222 OgOOOpOOOOOO p^f-^o (^ - 5 o> to bib APPENDIX D TABLES OF AUXILIARY TESTS OF MATERIALS Page 5. Tension Tests of Steel 350-352 6. Tension Tests of Metal Lath 353 7. Hardness Tests of Steel . . '. 353 8. Chemical Analyses of Steel 354 9. Transverse and Tension Tests of Cast Iron 354 10. Chemical Analyses of Cast Iron 354 11. Tests of Portland Cement by Bureau of Standards, Washington Lab- oratory 355 12. Tests of Portland Cement by Bureau of Standards, Pittsburgh Lab- oratory 356 13. Tests of Portland Cement by R. W. Hunt & Co., Chicago Laboratory. 357 14. Chemical Analyses of Sands 357 15. Physical Properties of Concrete Sands 358 16. Physical Properties of Mortar and Plaster Sands. . ; 358 17. Mortar Strength of Concrete Sands 359 18. Chemical Analyses of Coarse Aggregates 359 19. Physical Properties of Coarse Aggregates 359 20. Mineralogical Composition of Concrete Aggregates. . 360 21. Compressive Strength and Modulus of Elasticity of Concrete in Col- umns and Coverings 361-364 22. Compressive Strength and Modulus of Elasticity of Concrete in Head Protections 365 23. Tests of Lime 366 24. Tests of Calcined Gypsum 366 25. Compressive Strength of Portland Cement and Lime Plaster 367 26. Compressive Strength of Clay Tile Mortar 368-369 27. Compressive Strength of Gypsum Mortar and Plaster 370 28. Strength Tests of Mortar and Plaster 371 29. Compressive Strength of Gypsum Filling 369 30. Classification and Description of Hollow Clay Tile 372 31. Compressive Strength of Hollow Clay Tile 373-374 32. Transverse Strength of Hollow Clay Tile 375 33. Temperatures of Vitrification and Fusion of Clay Tile and Brick 376 34. Porosity and Absorption of Chicago Common Brick 376 35. Compressive Strength of .Chicago Common Brick 377 36. Transverse Strength of Chicago Common Brick 377 37. Porosity of Gypsum Block 378 38. Compressive Strength of Solid Gypsum Block 378 39. Transverse Strength of Solid Gypsum Block 379 40. Transverse Strength of Gypsum Wall Board 379 Note: For details of tests, see Sec. V (p. 67-83). 349 350 APPENDIX D OOC-.pOO pppp' ssssss ppppcoppoftpppppppppo p o us o p o ppppppp '9f-' t-i CO CO GO 1C b- - CO N CO O> r^ l^.' <-^l Cv| (M '5 MaT3T3 Me c'^'^'OMW-g WO HO O W>^O Jo^oooooooo^oopppppp o,pppop i mn Test No. TABLES OF AUXILIARY TESTS OF MATERIALS 351 II op ppppppp ppoo oo 38 ^t^oeoususcousMsooooi pp ppiopopp pppp 88 SSggJSSJS oo oio ooeoQoooooooootoico>o CCC^COC^POCC COCO I 1 ' 4 fc, ^ O O O go ^oooooo gooo o>o o>o J3 "O "O .5 O O O W K iMHMSin ^c PL, . . d JiiHiNi in.! .2 O JjOOOOpp 5JPOQ 5JT3 00^ J N .5000000 03 > 352 APPENDIX D t-~ LO o * oo woooeoooooooooocoeoec !88! I S2S 11 % ' ' : : | : : : : x = i |M !J: J: M : 1 |i : | g : M i g: o : 00 ; : ; % 1 s ; i 3 : CQ : : "g : : : J : : : : i 1 Miln; i c i iMl|M; = a LOOOOOPPOPQQQ ^00 w |0^ ^OO ^0000^ -, P H H ^ ^ -< < i in 520 R-3 Woven Wire Lath Sin. 250 (7 strands) TABLE 7. HARDNESS TESTS OF STEEL Column Test No. Specimen No. Section Location of Specimen Brinncll Hardness No. 2 17 37 51A 103 104 106 110 60 3 3 38 107 66 5 41 56 6 43 57 58 7 ' 26 60 61 H-2 E-17 E-37 E-51A H-103 H-104 H-106 H-110 H-60 HC-3 HP-3 H-38 H-107 H-66 H-5 H-41 H-56 H-6 H-43 H-57 H-58 H-7 H-26 H-60 H-61 Plate and Angle Edge of angle 113 121 118 118 121 125 * 131 126 123 Scleroscope Hardness No. 23 24 21 24 23 26 22 24 26 22 22 22 25 20 30 22 do do do . do do do do . do do do do do ... do . do Latticed angle do Plate and Channel do Center of channel web Plate do . do do Center of channel web . . Latticed channel Center of web Z-bar and Plate do Plate do do do Channel web ... . ... I-beam and Channel do Center of I-beam web do do . do do Latticed angle do ' . Edge of angle. . . do do do do do 354 APPENDIX D TABLE 8. CHEMICAL ANALYSES OF STEEL Column Test No. Specimen No. Carbon Manganese Phosphorus Sulphur Silicon 1 1 0.20 0.54 0.010 0.021 0.03 1 1A 0.18 0.54 0.015 0.028 0.01 1 IB 0.21 0.54 0.012 0.025 0.04 14 14 0.16 0.72 0.023 0.034 0.03 65 65 0.18 0.40 0.011 0.036 0.04 65 65-1 0.20 0.41 0.010 0.038 0.05 65 65-2 0.21 0.42 0.006 0.029 0.04 68 68 0.12 0.57 0.010 0.022 0.02 22 Rivets 0.09 0.007 0.050 46 Rivets 0.11 0.024 0.064 TABLE 9. TRANSVERSE AND TENSION TESTS OF CAST IRON Column Test No. Specimen No. Modulus of Rupture, Lb. per Sq. In. "Ultimate Tensile Strength, Lb. per Sq. In. 9 T-9 47800 23230 10 T-10 45800 29470 11 T-ll 43500 23900 27 T-27 64700 26700 47 T-47 23050 62 T-62 56100 28800 **10A 1CIA 17600 114 and 1CIB 39466 18300 115 1CIC 36200 17100 do 2CIA 45500 20300 do 2CIB 46300 21700 do 2CIC 45700 21600 "Tension specimens cut from ends of transverse specimens after test. ""Specimens cut from duplicate test column. TABLE 10. CHEMICAL ANALYSIS OF CAST IRON Column Test Specimen No Carbon Manganese Phosphorus Sulphur Silicon Graphite No. 9 T-9 0.61 0.47 0.57 0.090 1.86 2.66 10 T-10 0.67 0.50 0.57 0.090 1.86 2.77 11 T-ll 0.087 27 T-27 0.086 62 T-62 0.082 .... TABLES OF AUXILIARY TESTS OF MATERIALS 355 TABLE ll.-TESTS OP PORTLAND CEMENT By Bureau of Standards' Washington Laboratory DATE OF REPORT September 22, 1916 Dec. 19, 1916 SAMPLE No. 1 2 3 4 5 B-l B-2 12* Chemical Analysis: Silica (SiO 2 ) Oxide of Iron (Fe 2 O 3 ) 20.34% 2. li/Q 19.46% 2.70% 7.18% 20.36% 7.24% 20.28% 6^86% 20.40% 2.80% 6.74% 20.46% 2.75% 6.15% 20.82% 20.82% 7.14% Oxide of Aluminum (A1 2 O 3 ).. . . Lime (CaO) 63! 68% 62.12% 63.42% 64.32% 63.24% 62.86% 64 689' 59.50% Magnesia (MgO) Sulphuric Anhydride (SO 3 ) Loss of Ignition Insoluble Residue 1.13% 1-34% 4.53% 0.10% 1.21% 1.44% 3.43% 0.13% L45% 3.17% 0.17% 1-18% 1.45% 3.17% 0.20% 1.12% 3 22% 0.13% 0^16% 2,26% 0.13% 3.46% 1-50% 4.48% 0.70% Specific Gravity: As Received 3.06 3 09 3.08 3.08 3 08 3.10 3.12 After Ignition 3.17 3.18 3.16 3.22 3.15 3.17 Fineness: Passing 110-Mesh Sieve 94.8% 94.4% 97.0% 96.0% 97.0% 97.4% 96.4% 99.2% Passing 200-Mesh Sieve 77.6% 76.0% 77.4% 78.4% 77.0% 78.5% 78.1% 75.0% Tensile Strength, Lb. per Sq. In.: Neat, 7 Days 434 552 551 587 680 622 736 435 471 512 641 645 527 564 575 510 575 610 562 604 577 670 587 425 Neat, 28 Days 730 690 670 690 545 715 725 740 635 655 710 640 670 800 675 625 585 595 730 575 705 700 665 675 1 Cement: 3 Sand 7 Days 178 227 222 182 228 121 193 180 178 229 182 207 229 177 247 140 169 206 206 213 243 209 238 165 28 Days 280 295 325 325 330 265 365 375 310 300 310 335 340 280 380 380 260 265 310 330 290 325 330 340 Time of Set, hr. min.: Initial 7-30 7-15 7-30 7-10 7-20 7-30 Y-25 7-0 Final 11-50 11-30 11-55 11-45 11-40 11-50 11-00 10-30 Soundness: Pats 28 Days in Air O.K. O. K. O.K. O.K. O.K. O.K. O.K. O.K. 28 Davs in Water O.K. O.K. O.K. O.K. O.K. O.K. O.K. O.K. 5 Hr. in Steam - O.K. O. K. O.K. O.K. O.K. O.K. O.K. O.K. Water Used: Neat 25.0% 25.0% 25.0% 25.0% 25.0% 25.0% 25.0% 23.0% 1:3 Mortar . . 10.7% 10.7% 10.7% 10.7% 10.7% 10.7% 10.7% 10.3% 'Portland cement used in pipe column, Test No. 12. 356 APPENDIX D TABLE 12. TESTS OF PORTLAND CEMENT By Bureau of Standards' Pittsburg Laboratory DATE OF REPORT May 1, 1917 June 19, 1917 Nov. 19, 1918 SAMPLE No. H-l H-2 H-3 H-5 H-6 H-7 H-8 Specific Gravity: As Received 3.15 3.16 95.0% 77.2% 516 555 521 725 735 650 190 208 245 358 371 376 7-0 Over 10 hrs. O.K. 24.0% 10.5% 3.18 3.18 96.0% 77.7% 598 550 510 750 688 681 204 242 223 282 332 345 7-0 Over 10 hrs. O.K. 24.0% 10.5% 3.18 3.19 95.4% 77.0% 695 685 650 700 690 776 261 260 269 322 326 340 7-0 Over 10 hrs. O.K. 24.0% 10.5% 3.10 3.11 3.11 3.12 After Ignition . . Fineness: Passing 100-Mesh Sieve 94.0% 762% 621 474 530 585 600 570 203 225 212 315 331 382 Over Ihr. Over 10 hrs. O.K. *24.0% 10.5% 94.2% 76.4% 450 521 543 661 575 691 205 225 239 349 381 352 Over Ihr. Over 10 hrs. O.K. 24.0% 10 5% Passing 200-Mesh Sieve 78.8% 78.6% Tensile Strength, Lb. per Sq. In.: Neat 7 Days Neat, 28 Days 300 260 300 410 430 400 3-50 8-50 O. K. 310 300 305 440 470 460 3-50 9-0 O.K. 1 Cement: 3 Sand 7 Days 28 Days Time of Set, hr. min.: Initial Final Soundness: Pats 5 Hr. in Steam Water Used: Neat 1:3 Mortar TABLES OF AUXILIARY TESTS OF MATERIALS 357 TABLE 13. TESTS OF PORTLAND CEMENT By E. W. Hunt & Company DATR OF REPORT SAMPLE No. May 2, 1917 H-l H-2 Specific Gravity: AsReceived 3 14 3 13 Fineness: Passing 100-Mesh Sieve 95. 4^ 96 0^ Passing 200-Mesh Sieve '.'.'.'.'. 76~4% 78 0^ Tensile Strength, Lb. per Sq. In.: Neat, 24 Hr 305 355 320 330 Neat, 7 Days ..- 690 625 640 640 Neat, 28 Days 730 765 765 725 1 Cement, 3 Sand: 7Days ' . . . 310 330 330 310 28 Days 410 385 380 395 405 410 Time of Set, hr. min.: Initial ' 5-45 5-40 Final g-05 g_o Soundness: Pats 5 Hr. in Steam O. K. O.K. Water Used: Neat r 23.0% 23.0% 1:3 Mortar 10.3% 10.3% TABLE 14. CHEMICAL ANALYSES OF SANDS SAND Insoluble in Acid and Fe 2 3 CaO MgO CO, Fox River Joliet Meramec River. Long Island .... Pelee Island.... Plum Island.... Cambridge Coarse lake Fine lake Beach Bank... 54.51 52.10 98.66 97.98 64.70 98.18 96.93 83.53 87.69 85.45 91.30 1.34 1.19 0.58 0.96 1.66 0.66 1.63 6.69 5.38 5.60 5.18 14.90 15.46 0.14 0.04 17.03 0.16 0.17 3.31 2.17 2.35 0.09 8.97 0.06 0.18 1.34 0.12 0.90 1.21 0.93 1.02 0.51 21.22 23.06 0.11 0.25 15.68 0.18 0.25 3.30 1.95 2.29 0.22 Not including CO,. 358 APPENDIX D O "s fa ?j I^S* CO *-<- <3> d d es eo d o M oo IQ i ci c C-J 5 Q Q g "S : "g I a g.2 -5 : -s S|8 "1** 8 ills 1 fi 1| jl i b . i-I g t^ 10 CO i s S a>f d ^3 j d d o a 3& o en ^ ^ SSoo .-' .-.- _ 1 : ' i *Jf 1| i| | * 1 i ; c 1 : s 8 G l ^s i ? Id! a s II OO IM 5 co ^ ; 35 o OO M aT S go " ! s 1 ; ! I J : 1 : M " ' ' S o o ; H - 1 1 1 1 ? a -2 J C5 1 1*1 > ** ' g "q AGGRE i 1 1 ! 1 1 1 Joliet gravel Meramec Ri fjfl TABLES OF AUXILIARY TESTS OF MATERIALS TABLE 21. COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY OF CONCRETE IN COLUMNS AND COVERINGS Cylin- der No. Kind of Concrete Age, Days Per- cent .Water Ultimate Stress, Lb. per Sq.In. Modulus of Elasticity, Lb. per Sq. In. Unit Stress 450 650 850 22-1 22-2 22-3 22-4 28-1 28-3 28-2 28-4 28A-1 28A-3 28A-2 28A-4 33-1 33-3 33-2 33-4 33A-1 33A-3 33A-2 33A-4 70-1 70-3 70-2 70-4 72-1 72-3 *2-2 72-4 74-1 74-3 74-2 74-4 101-5 101-6 102-1 102-2 111-1 111-2 112-5 112-6 19-1 19-2 19-3 19-4 35-1 35-3 35-2 35-4 41-1 41-3 41-2 41-4 42-1 42-3 42-2 42-4 55-1 55-3 55-2 55-4 66-1 56-3 56-2 56-4 57-1 57-3 57-2 1:2:4 Chicago limestone do . 28 29 407 407 28 28 438 438 28 28 439 439 25 25 452 452 29 29 458 456 28 28 434 ;.*;:.'.'!.' 912 1049 1888 1780 2935 3308 3830 3470 1738 1647 2370 2213 1489 1728 1956 2273 1255 1676 1574 1881 2027 1778 3182 2743 1010 1582 1656 2114 704 739 922 935 1495 2485 1455 2363 1554 2735 1493 2042 2056 2168 2561 1880 1284 1618 1540 1468 1355 1132 1485 1313 1169 1042 1943 1216 718 577 794 678 811 614 682 869 912 947 921 do do 2,060,000 2,390,000 2,490,000 2,400,000 2,780,000 2,310,000 do do . do 5,270,000 4,400,000 do 4,470,000 4,620,000 do do * do . 4,300,000 3,960,000 3,900,000 3,550,666 3,500,000 do do 12.1 12.1 12.1 12.1 12.9 12.9 12.9 12.9 do do 2,660,000 4,000,000 2,300,000 3,730,000 1,990,000 3,350,000 do do do 2,950,666' 3,350,000 2,680,666 3,100,000 do 2,450,000 2,950,000 do do do do 4,280,000 3,750,000 3,950,000 3,730,000 3,860,000 3,490,000 do 434 29 29 521 521 28 T28 523 523 28 520 28 514 28 520 28 521 29 29 414 414 32 32 505 505 29 29 452 452 28 27 450 450 29 29 483 483 28 28 492 492 28 28 483 "isii" 12.7 13.1 12.7 12.0 11.8 12.0 11.8 12.7 12.7 12.2 12.2 12.5 12.5 10.6 10.6 do do do 2,730,000 2,500,000 2,250,000 2,970,000 do do do do 1,420,000 1,760,000 7,970,666 760,000 1,160,000 ' 5,996',666' ' 250.000 490,000 s.oso'.ooo' do do do do do 4,050,000 3,760,000 3,740,000 do do 5,000,000 4,320,000 4,450,000 do do 1:3:5 Chicago limestone. . 3,640,000 3,460,000 3,350,000 do 4,000,000 3,350,000 3,940,000 3.160,000 3,790,000 3,120,000 do do 12.8 12.8 12.8 12.8 13.0 13.4 13.0 13.4 13.3 12.6 13.3 12.6 13.7 15.2 13.7 15.2 13.3 12.9 13.3 12.9 12.7 12.9 12.7 do do 3,270,000 4,070,000 2,940,000 3,760,000 2,520,000 3,470,000 do do do do ... 2,830,000 2,590,000 2,520,000 2,450,000 2,300,000 2,200,000 do do do do 3,450,000 2,350,000 3,180,000 2,000,000 3,150,000 1,640,000 do Ho j_ do 1,330,000 1,630,000 490,000 do do Hn do 1,280,000 1,280,000 400,000 750,000 do Hn Hr do 1,600,000 900,000 350,000 362 APPENDIX D TABLE 21. COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY OF CONCRETE IN COLUMNS AND COVERINGS Continued Cylin- der No. Kind of Concrete Age, Days Per- cent Water Ultimate Stress, Lb. per Sq. In. Modulus of Elasticity , Lb. per Sq. In. Unit Stress 450 650 850 57-4 76-1 76-2 77-1 77-2 106-1 106-4 106-2 106-3 16-1 16-2 16-3 16-4 18-1 18-2 18-3 18-4 29-1 29-3 29-2 29-4 36-1 36-3 36-2 36-4 37-1 37-3 37-2 37-4 40-1 40-3 40-2 40-4 46-1 46-3 46-2 46-4 60-1 60-3 60-2 60-4 71-1 71-3 71-2 71-4 73-1 73-3 73-2 73-4 75-1 75-3 75-2 75-4 101-3 101-4 102-5 102-6 104-1 104-2 20-1 20-2 20-3 20-4 21-1 21-2 21-3 214 54-1 54-2 1:3:5 Chicago limestone do do 483 59 59 59 59 28 29 532 532 29 29 416 416 28 28 419 419 29 29 437 437 29 29 445 445 30 30 504 504 28 28 502 502 28 29 455 455 27 27 290 490 29 29 451 451 28 28 443 443 28 28 462 462 28 541 28 516 32 527 30 30 415 415 28 28 416 416 29 488 12.9 13.7 13.7 13.7 13.7 13.9 13.9 13.9 13.9 1040 523 688 842 508 767 813 820 946 1023 1163 2512 1219 1158 1764 1529 1884 1494 1239 1807 1985 1490 1548 2284 2118 995 1668 2278 1103 1797 1780 2180 2300 1418 1641 1659 2082 948 1028 1490 1039 1572 957 1446 1109 2239 2484 2658 3224 1361 1756 1918 2318 1307 2115 1510 2692 978 1542 1254 1158 1109 958 702 678 874 986 780 1012 2,030,000 190,000 340,000 1,360,000 210,000 1,550,000 1,000,000 240,000 950,000 do . . do do do do ... 1,770,000 2,230,000 1,200,000 1,460,000 do 1,060,000 1:2:4 New York trap do do 4,750,000 1,100,000 4,340,000 650,000 3,860,000 330,000 do do do do 1,900,000 3,320,000 1,570,000 2,600,000 1,030,000 1,840,000 do do . 13.1 13.6 13.1 13.6 12.2 12.0 12.2 12.0 12.6 12.7 12.6 12.7 11.2 11.1 11.2 11.1 13.9 13.9 13.9 13.9 14.6 14.6 14.6 13.8 13.7 13.0 13.7 13.0 do do . 2,570,000 3,140,000 2,390,000 2,870,000 2,210,000 2,640,000 do do . do do do . 2,750,000 3,100,000 2,750,000 2,960,000 2,600,000 2,650,000 do . do do do 2,780,000 820,000 2,620,000 530,000 2,450,6o6 350,000 do do do 3,140,000 4,170,000 2,960,000 3,450,000 2,750,000 3,150,000 do do do do 1,870,000 2,730,000 1,700,000 2,510,000 1,460,000 2,300,000 do do do do 2,510,000 1,940,000 2,140,000 1,530,000 1,810.000 1,200,000 do do do do 2,450,000 1,000,000 1,970,000 400,000 1.650,000 230,000 do . do do do 4,180,000 3,900,000 3,960,000 4,060,000 3,720,000 3,830,000 do do "io!6" 10.3 ' 10.0 10.3 13.2 13.2 11.9 11.9 11.1 11.1 do do 1,500,000 2,790,000 1,610,000 2,770,000 1,740,000 2,700,000 do do do do 4,850,000 4,480,000 4,090,000 do . 3,020,000 3,900,666" 3,060,000 3,5i6',666" 3,070,000 do do 2,350,000 1:3:5 New York trap do do do 4,950,000 8,700,000 940,000 330,000 450,000 do do do 590,000 900,000 270,000 520,000 do 250,000 do 12.6 12.6 do 1,330,000 1,850,000 530,000 TABLES OF AUXILIARY TESTS OF MATERIALS 363 TABLE 21. COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY OF CONCRETE IN COLUMNS AND COVERINGS Continued Cylin- der No. Kind of Concrete Age, Days Percen Water Ultimate Stress, Lb. per Sq. In. Modulus of Elasticity, Lb. per Sq. In. Unit Stress 450 650 850 15-1 15-2 15-3 15-4 34-1 34-3 34-2 34-4 34A-1 34A-3 34A-2 34A-4 103-1 103-2 113-k 113-2 50-1 50-3 '50-2 50-4 50A-1 50A-3 50A-2 50A-4 51-1 51-4 51-2 51-3 51A-1 51A-4 51A-2 51A-3 31-1 31-3 31-2 31-4 43-1 43-3 43-2 43-4 104-3 104-4 44-1 44-3 44-2 44-4 11-1 11-4 11-2 11-3 14-1 14-2 14-3 14 4 30-1 30-3 30-2 30-4 38-1 38-3 38-2 38-4 101-1 101-2 102-3 102-4 1 :2:4 Rockport granite do 30 30 407 407 29 29 453 453 28 28 455 455 28 522 32 527 28 28 487 487 28 28 509 509 29 29 485 485 29 29 507 507 30 30 501 501 29 29 456 456 32 527 29 29 459 459 27 27 468 468 28 28 406 406 28 28 440 440 29 29 451 451 28 520 28 514 i2!6' 11.5 12.0 11.5 12.7 10.7 12.7 10.7 13.0 13.0 12.2 12.2 13.5 13.5 13.5 13.5 11.5 11 5 11.5 11.5 14.0 14.0 14.0 14.0 14.1 14.1 14.1 14.1 14.0 14.2 14.0 14.2 14.0 14.0 14.0 14 14.9 14.9 14.7 14.7 14.7 14.7 11.3 11.3 11.3 11.3 1478 1181 1773 2315 1638 1308 2211 1903 853 1633 1157 1833 993 1645 1017 1476 919 621 1082 1063 734 660 1255 1073 729 703 924 688 683 822 877 1272 2040 1988 2828 2531 746 1855 2128 2658 1535 2720 1418 661 1662 1042 2365 1764 2190 2522 1070 1192 2177 1268 762 1908 898 2690 1080 1290 1872 1721 1401 2408 1720 295 do 2,800,000 2,470,000 2,730,000 2,540,000 2,600,000 2,540,000 do do . do 2,800,666' 3,160,000 2,060,666' 2,680,000 ' 2,576",666" 2,900,000 2,390',666 ' 2,550,000 do do do do do . 1,750,000 2,670,000 3,ib6",666" 1.350,000 2,560,000 ' 2,960',666' ' do do . do 3,620,000 do . do 1:3:5 Rockport granite do 2,480,000 2,220,000 do 2,150,000 2,380,000 1,800,000 1,850,000 1,350,000 1,280,000 do do . do "2,4o6',666' 2,750,000 i,95o,666' ' 2,430,000 do 1,650,000 2,220,000 do do do do . 1,480,000 1 ,480,000 1,130,000 750,000 do . do do . do 2,170,000 2,270,000 1,260,000 2,230,000 640,000 2,000,000 do 1:2:4 Cleveland sandstone. . do do 1,410,000 1,230,000 1,410,000 1,230,000 1,410,000 1,200,000 do do do do 1,420,000 1,430,000 1,290.000 1,350,000 1,230,000 1,270,000 do do do 1:3:5 Cleveland sandstone. . do do 2,270,000 2,020,000 1,670,000 4,130,000 880,000 3,040,000 720,000 2,050,000 600,000 do 1:2:4: Joliet gravel do 3.63b'.666" 3,630,000 3,160,666' ' 3,530.000 3,126,666' ' 3,400,000 do do do do "io.'s" 10,8 10.8 10.8 11.0 11.0 11.0 11.0 do 3,670,000 2,940,000 3,470,000 2,620,000 do 3.380,000 do do do 2.250,000 3,240,000 1,550,000 3,210,000 620,000 3,200,000 do do do 3',350',666' ' 3,500,000 3,810,666" 3,660,666' ' 3,220,000 3,750,666' ' 2,840,666 ' 3,130,000 3,6o6',666' ' do . do do do do do 4,880,000 4,370,000 4,130,000 364 APPENDIX D TABLE 21.-COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY OP CONCRETE IN COLUMNS AND COVERINGS Concluded c r No. Kind of Concrete Age, Days Percent Water Ultimate Stress, Lb. per Sq. In. Modulus of Elasticity, JJ>. per Sq. In. Unit Stress 450 650 850 112-1 112-2 39-1 39-3 39-2 39-4 45-1 45-3 45-2 45-4 112-3 112-4 17-1 17-2 17-3 17-4 32-1 32-3 32-2 32-4 32A-1 32A-3 32A-2 32A-4 47-1 47-3 47-2 47-4 52-1 52-2 52-3 52-4 53-1 53-3 53-2 53-4 104-6 104-6 12-1 12-2 12-3 12-4 1:2:4 Joliet gravel do 28 521 28 28 437 437 25 25 447 447 28 521 28 28 408 408 29 29 504 504 32 32 498 498 28 28 447 447 28 28 492 492 30 30 494 494 32 527 28 28 534 533 9.7 9.7 "ii's 12.3 11.8 12.3 10.7 10.7 2004 2973 2053 1220 2580 1721 2056 1987 2707 2374 1719 2952 671 1307 1691 2072 495 728 970 977 628 759 950 796 949 907 1335 1258 901 914 929 879 306 492 635 691 797 1313 2397 1312 3880 4180 4,290,000 4,160,000 4,140,000 1:2:4 Meramec R. gravel. . . do 3,450,666 3,550,000 ' 3,566',666' ' 3,500,000 do 3,430,000 3,430.000 do do do do 4,600,000 3,870,000 ' 3,310,666' ' 4,370,000 3,920,000 ' 3,510.666 4,040,000 3,900,000 ' 3,666',666' ' do do do 1:1^:4^ Hard coal cinders do do "MY" 22.9 22.9 22.9 17.3 18.5 17.3 18.5 22.1 22 4 22.1 22.4 22.3 22.3 22.3 22.3 29.1 29.1 29.1 29.1 22.9 22.9 1,730,000 1,900,000 1,500,000 1,770,000 1,330,000 1,670,000 do 1:2:5 Hard coal cinders do do do 1,080,000 1,250,000 900,000 1,000,000 700,000 610,000 do do do 900,000 750,000 720,000 530,000 500,000 do do do do 1,070,000 1,150,000 1,050,000 1,030,000 970,000 890,000 do do do . ' 1,146,666 1,300,000 926.666 920,000 580',666' ' 450,000 do do . do do '1,666,666 1,190.000 do do 670,000 do do 1,340,000 1,280,000 1,190,000 l:l^:3Westfieldtrap do do 3,520,000 4,890,000 3,370,000 4,450,000 3,270,000 4,130,000 do TABLES OF AUXILIARY TESTS OF MATERIALS 365 TABLE 22.-COMPRESSIVE STRENGTH AND MODULUS OF ELASTICITY OF CONCRETE IN HEAD PROTECTIONS Cylin- der No. Kind of Concrete Age, Days Percent Water Ultimate Stress, Lb. per Sq. In. Modulus of Elasticity, Lb. per Sq. In. Unit Stress 450 650 850 49-1 49-3 49-2 49-4 59-1 59-3 59-2 59-4 *64-l *64-4 *64-2 *64-3 65-1 65-4 65-2 65-3 69-1 69-3 69-2 69-4 A-l A-3 A-2 B-l B-3 B-2 B-4 B-5 48-1 48-3 48-2 48-4 62-1 62-3 62-2 62-4 63-1 63-2 63-3 63-4 *67A-1 *67A-2 *67A-3 *67A-4 49-5 49-7 49-6 49-8 68-1 68-4 68-2 68-3 58-1 58-4 58-2 58-3 105-5 105-8 105-6 105-7 106-5 106-8 106-65 106-7 105-1 105-4 105-2 105-3 109-5 109-7 109-6 109-8 1:2:4 Chicago limestone. . . . do 28 28 489 489 29 29 494 494 27 27 502 502 27 27 502 502 29 29 497 497 28 28 520 28 28 520 524 524 28 28 489 489 28 28 492 492 27 27 496 496 28 28 493 493 28 28 489 489 30 30 494 494 28 28 498 498 28 28 538 538 29 28 532 532 28 28 538 538 28 28 509 509 11.2 11.2 11.2 11.2 10.5 10.5 10.5 10.5 9.8 9.8 9.8 9.8 9.7 9.7 .9.7 9.7 10.9 10.9 10.9 10.9 9.6 9.6 9.6 11.2 11.2 11.2 11.2 11.2 11.5 11.5 11.5 11.5 11.2 11.2 11.2 11.2 11.1 11.1 11.1 11.1 10.3 10.3 10.3 10.3 10.6 10.6 10.6 10.6 9.8 9.8 9.8 9.8 13.4 13.4 13.4 13.4 10.5 10.5 10.5 10.5 10.7 10.7 10.7 10.7 9.8 9.8 9.8 9.8 8.7 8.7 8.7 8.7 1473 1510 2673 2178 990 962 1085 1319 3428 3119 4036 4000 2120 1951 3157 2813 1874 1698 2469 2941 2058 1947 2960 1986 2197 3131 2282 2527 961 1736 1358 2397 881 1324 1731 1613 1403 1280 2175 1872 1945 1998 2573 2406 1395 1509 2212 2233 1307 1495 1606 1930 841 946 1172 1263 1128 1355 1921 1723 1396 1403 1653 2076 1721 1691 2699 2706 2152 2021 3232 3095 ' 8,966",666' 3,870,000 2,'i76',666' 3,780,000 ' 8,8i6',666' 4,230,000 ' 6,666',666' 3,320,000 ' 6,666',666' ' 3,140,000 do do do do . 1,376,666' 2,870,000 7,946',666' ' 4,060,000 do 830,000 2,250,000 7,586',666' ' 4,060,000 do do do do ...... .. do do do . 6,566,666' 4,300,000 4,i56',o66' ' 7,080,000 do 5,990,000 4,050,000 3,886',666' 5,620,000 5,830,000 3,770,000 3,750,666 5,000,000 do do do do . do do . do do 4,040,000 4,020,000 3,810,000 do :.. do . do 4,060,000 3,400,000 4,100,000 3,940,000 3,420,000 4,070,000 3,770,000 3,300,000 4,090,000 2,400,666' ' 3,570,000 do do 1:3:5 Chicago limestone do do 2,810,000 3,750,000 4,586',o6o" 2,900,000 2,710,000 3,710,000 4,266',666' ' 2,770,000 do . do do do 3,730,000 2,370,000 do 1:2:4 New York trap do 2,756',666' 3,090,000 2,486,666 2,770,000 2,380,666' ' 2,430,000 do . do do do do 4,896',666' 7,950,000 4,080,000 6,480,000 1,780,000 do 1:2:4 Rockport granite do do 6,650,000 3,790,000 4,230,000 3,490,000 3,640,000 2,900,000 *' do . do do do do 1:3:5 Rockport granite do do 3,580,000 4,080,000 2,510,666 2,430,000 2,950,000 4,000,000 2,676,666' ' 2,030.000 2,570,000 3,500,000 1,670,666' ' 1,770,000 do 1:2:4 Joliet gravel do 3,336,606 2,560,000 3,250,000 ' 3,350,000 3,166,666' ' 2,130,000 3,106,660' 3,430,000 do do 3,480,000 2,800,000 3,460.066 3,920,000 do do do . do 1:2:4 Meramec R. gravel. . . do 5,030,666 3,040,000 8,100,666 5,060,000 4,606,666 3,090,000 5,716,066 4,350,000 4,230,666 3,060,000 5,666,666 4,190,000 do do do . do do do * *Time of mixing, 2 min. For all other cylinders time of mixing was 1 min. Cylinder No. 64-2 failed on third application of maximum load; No. 64-3 on second application of maximum load. 366 APPENDIX D TABLE 23.-TESTS OF LIME Sample No. Quick Lime Hydrated Lime 1 2 1 2 Chemical Analysis: Impurities (SiO 2 and R 2 O 3 ) 1.73% 88.98 1.70% 85 53 1-44% 69.59 1.31% 69.59 CaO MgO 1.26 0.89 1.37 1.37 Loss on Ignition 8.22 8.22 27.02 27.07 CO2 Average 0.66 4.89 Fineness: Residue on No. 20 Sieve, Sample Slacked and Washed Through 1.25 Residue on No. 30 Sieve, Original Sample, Dry. . Residue on No.200 Sieve, Sample Washed Through 4.4 3.97 Soundness: Pats 5 Hr in Steam Unsound TABLE 24. TESTS OF CALCINED GYPSUM Western Eastern Chemical Analysis: Impurities (SiO and RaO 3 ) 3 55% 2 10% CaO . .... 36.77 36.93 so a 52.22 51.37 Loss Below 60C 1 23 1.12 Loss Between 60C and Tyrrell Burner 6.67 8.35 Time of Set: Neat 55 percent Water . More than 7 hr.; less 24 hr. Tensile Strength: Lb. per Sq. In. Neat 55 percent Water than 16 hr. 200.0 Easily 1 Gypsum* 3 Ottawa Sand 22 percent Water . . 190.0 192.0 97.0 crumbles No test obtainable 175.0 102.0 85.0 150.0 150.0 *Mortars made up with distilled water and after setting 24 hr. in air, were dried to constant weight below 60C. and then broken. TABLES OF AUXILIARY TESTS OF MATERIALS 367 TABLE 25. COMPRESSIVE STRENGTH OF PORTLAND CEMENT AND LIME PLASTER Test specimens 2-in. cubes stored in air Cube No. Proportion, Parts by Loose Volume of Materials as Used Percent Water Age, Days Compressive Strength, Lb. perSq.In. 23-1 1 Portland cement 1 /10 Hydrated lime 15.78 28 1080 23-2 2H Coarse lake sand do 15 78 28 1055 23-3 23-4 do do 15.78 18 23 512 29 1623 1488 23-6 do .. 18 10 29 1795 23-7 do 18 10 511 2385 23-8 do 15.23 28 2715 23-9 do 15 23 509 3828 24-1 do 16.23 28 1839 24-2 do .... 16 23 501 2855 24-3 do 17.79 29 1350 24-4 do 17 79 498 2140 24-5 do 12.87 29 933 24-6 do 12 87 496 1669 25-1 do 16 20 28 2520 25-2 do 16 20 487 3956 25-3 do . 18.50 29 1319 25-4 do 18.50 484 2480 26-1 do 18 35 29 1655 26-2 do 18.35 500 3035 26-3 26-4 do do 15.82 15.82 28 498 2685 3744 27-1 do 18 00 29 1645 27-2 do 18.00 501 3191 27-3 do 16.50 29 976 27-4 do 16 50 499 1934 78-1 do 19.52 38 818 78-2 do .... 19 52 38 795 78-3 do 19.52 38 1083 78-4 do ... 19 52 38 640 78-5 do 19.52 38 610 78-6 do 19 52 38 790 78-7 do 21.15 34 991 78-8 do 21.15 34 583 78-9 do 21.15 34 1035 110-1 do 21 60 28 1455 110-2 do 21.60 28 1200 110-3 do 21.60 28 1225 110-4 do 21 60 514 1805 110-5 do 21.60 514 1595 110-6 do ... 21 60 514 1946 110-7 do 17.20 28 1913 110-8 do .... 17 20 28 1748 110-9 do 17.20 28 1716 110-10 do 17 20 512 2181 110-11 do 17.20 512 3408 110-12 do 17 20 512 2639 110-13 do . ..* 19.00 28 1789 110-14 do 19 00 28 1863 110-15 do 19 00 28 1831 110-16 do 19.00 507 1960 110-17 do 19 00 507 2990 110-18 do 19.00 507 2753 110-19 do 19 02 29 2084 110-20 do 19.02 29 2020 110-21 do 19 02 29 1710 1 10-22 do 19 02 500 2838 110-23 do 19 02 500 2758 110-24 do . . 19 02 500 3248 77-4 1 Slaked lime 2J^ Fine lake sand . . . 18.36 60 158 77-5 do 18.36 60 149 368 APPENDIX D TABLE 26. COMPRESSIVE STRENGTH OP CLAY TILE MORTAR Test specimens 2-in. cubes stored in air Cube No. Proportion, Parts by Loose Volume of Materials as Used Percent Water Age, Days Compressive Strength, Lb. per Sq. In. 48-1 1 Slaked lime 24.00 28 955 48-2 do 24.00 28 873 48-3 do 24.00 499 1040 48-4 do 24.00 499 769 48-5 do 27.50 28 763 48 6 do 27.50 512 833 49-1 do 25.00 28 421 49-2 do 25.00 498 485 49-3 do 27.15 28 410 49-4 do 27.15 498 405 50-1 do 26.00 26 273 50-2 do 26.00 496 361 , 5i_i do 25.70 28 385 51-2 do 25.70 497 358 51-3 do 28.45 28 278 51-4 do 28.45 497 308 51A-1 do 24.45 29 303 51A-2 do 24.45 516 313 63-1 do . 24.40 28 445 53-2 do 24.40 503 370 5&-1 do . 24.60 28 455 66-2 do 24.60 28 399 66-3 do 24.60 500 565 56-4 do .... 24.60 500 550 57-1 do 22.70 29 513 67-2 do 22 70 497 700 68-1 do 24.80 28 288 68-2 do . 24.80 504 373 68-3 do 24.10 28 340 58-4 do 24.10 504 348 58-5 do 28 00 28 283 68-6 do . 28.00 604 325 69-1 do 25 90 28 " 395 59-2 do . 25.90 498 333 59-3 69-4 do v do 24.75 24 75 28 497 368 270 60-1 do .. 25.00 28 296 60-2 do 25 00 505 285 60-3 do .. 26 60 28 360 60-4 do 26 60 505 358 61-1 do .. 28 05 29 513 61-2 do 28 05 29 390 61-3 do . 28 05 524 473 61-4 do 28.05 524 628 61-5 do . 23 50 29 415 61-6 do 23 50 524 480 62-1 do 25.30 28 475 62-2 do 25.30 483 551 63-1 do . 28 25 28 318 63-2 do 28 25 505 350 68-1 do . 29 50 28 310 68-2 do 29 50 503 270 68-3 do . 24 10 28 285 68-4 do 24 10 503 323 69-1 do . >! 80 516 463 69-3 do 24 45 29 318 69-4 do . 24 45 516 338 69-5 do 21 45 28 853 69-6 do 21.45 515 940 69-7 do 22 65 29 653 69-8 do . 22 65 28 663 69-9 do ' " 22 65 493 773 TABLES OF AUXILIARY TESTS OF MATERIALS 369 TABLE 26. COMPEESSIVE STRENGTH Of CLAY TILE MORTAR Concluded Test specimens 2-in. cubes stored in air Cube No. Proportion, Parts by Loose Volume of Materials as Used Percent Water Age, Days Comprcssive Strength, Lb.perSq.Jn. 9-10 1 Portland otment . 1 Slaked lime 22.65 493 708 4 Bank or beach sand . 76-1 do . 23.75 60 495 76-2 do 23 75 60 571 76-3 do 23 75 60 688 77-1 do 23.75 60 380 77-2 do 23 75 60 385 77-3 do 23.75 60 360 62-2 1 Portland cement 2 Slaked lime 29.40 38 228 6 Bank sand . - 62-5 do 30.30 29 100 64-5 do 26.60 28 159 64-0 do 26.60 498 216 64-1 1 Portland cement . . . \X Hydrated lime 20.90 28 803 6 Bank sand . . 64-3 do 20.90 28 395 64-4 do 20.90 499 626 TABLE 29. COMPRESSIVE STRENGTH OF GYPSUM FILLING Test specimens 8 by 16 in. cylinders Cylinder No. MATERIAL Proportions, Parts by Loose Volume of Materials as Used Per- cent Water Age, Days Ultimate Strength, Lb.per Sq. In. 66-1 66-5 66-6 67A-5 67A-8 67A-7 67A-8 109-3 109-4 108-1 108-2 108-3 108-4 109-1 109-2 Eastern gypsum filling do 1 Eastern calcined gypsum . . 54.70 61.20 61.20 60.15 60.15 60.15 60.15 52.20 52.20 63.30 63.30 63.30 63.30 63.10 63.10 31 29 483 29 29 489 489 15 31 95 22 17 105 85 1 Fine lake sand 4 Broken gypsum blocks do do do do do do do do do do do Specimen collapsed on remo Broken during storage Western gypsum filling do val of mould 12 days after placement 1 Western calcined gypsum . . 28 28 513 513 28 509 27 33 42 32 29 40 1 Fine lake sand 4 Broken gypsum blocks do do do do do do do do do Based on total weight of dry materials in mixture. 370 APPENDIX D TABLE 27. COMPRESSIVE STRENGTH OF AND PLASTER GYPSUM MORTAR Test specimens 2-in. cubes stored in air Cube No. Proportion, Parts by Loose Volume of Materials as Used *Percent Water Age, Days Compressive Strength, Lb.perSq. In. 64-1 1 Western calcined gypsum 3 Fine lake sand 23 40 30 220 64-3 do . 23.40 30 145 64-4 do 23 40 523 118 64-5 do . 23.40 523 94 65-1 do 22 20 29 233 65-2 65-3 do do 22.20 22 20 29 29 275 275 65-4 65-5 do do 22.20 22 20 522 522 202 214 66-1 1 Eastern calcined gypsum 3 Fine lake sand 23 50 29 43 66-2 66-3 do do 23.50 23 50 29 29 13 15 66-5 do ...... 23.50 504 35 67-1 do 23 10 28 193 67-2 do 23.10 28 105 67-3 do . 23.10 28 213 67-5 do 23 10 520 152 67-6 do . 23.10 503 160 67A-1 do 22 85 31 215 66A-2 67A-3 do , do 22.85 22 85 31 31 130 188 67A-6 108-1 do do 22.85 22 60 497 27 83 189 108-2 108-3 do do 22.60 22 60 27 48' I 201 83 108-4 do . 20.60 91 240 108-5 do 20 60 4S'J 139 108-6 do . 20.60 489 172 109-1 do 22 2 28 70 109-2 do . 22.2 28 86 109-3 do 22 2 515 75 109-4 do . 22.6 515 130 109-5 do 22 6 28 200 109-6 do 22.6 515 222 76-4 1 Fibered gypsum plaster 3 Fine lake sand 17.20 60 443 76-5 do 17.20 60 468 76-6 1 Calcined gypsum 61 00 60 958 77-6 do . 61.00 60 1029 *Based on total weight of dry materials in mixture. TABLES OF AUXILIARY TESTS OF MATERIALS 371 TABLE 28. STRENGTH TESTS OP MORTAR AND PLASTER Test specimens, 1-in. briquettes for tension tests and 2-in. cubes for compression tests made in laboratory. Each value is the average of three tests. Mortar or Plaster Proportion, Parts by Loose Volume of Materials as Used *Per- cent Water Method of Storage Age, Days Stre Lb Sq Ten- sile ngth, 'in* Com- pres- sive Clay tile mortar . . . 1 Portland cement 25.0 25.0 25.0 25.0 25.0 25.0 '25.6' 25.0 25.0 25.0 16.7 16 7 16.7 16.7 16.7 16.7 16.7 16.7 22.0 22.0 22.5 22.5 22.0 22.0 22.0 22.0 22.5 22.5 22.5 22.5 1 day in damp closet remainder of period in water do do do do do 7 7 7 28 28 28 28 28 28 365 365 7 7 28 28 28 28 365 365- 2 2 2 2 28 28 365 365 28 28 365 365 67 72 65 97 114 91 161 257 236 174 425 496 369 848 328 190 442 259 418 363 1105 721 1010 616 1297 963 491 343 647 517 786 415 1180 698 do 1 Slaked lime 4 Bank sand do with beach sand do with Ottawa sand do with bank sand do with beach sand do do do do do with Ottawa sand do with Ottawa sand do do do 1 day in damp closet remainder of period in air do do do 1 day in damp closet, remainder of period in water do do do 1 day in damp closet .remainder of period in air do do do I day in air, then dried to constant weight below 60C. do do do In air for whole >eriod. do do do with Ottawa sand do with bank sand do with Ottawa sand 1 Portland cement do do 144 114 197 154 126 95 202 158 Portland cement plastei . . do 1/10 Hydrated lime 2^ Coarse lake sand do with Ottawa sand do with coarse lake sand . . do with Ottawa sand do with coarse lake sand. . do with Ottawa sand . do do do do . do do with coarse lake sand. . . do with Ottawa sand 1 Western gypsum cement 3 Fine lake sand do Western gypsum block mortar do Eastern gypsum block mortar do .... do with Ottawa sand 1 Eastern gypsum cement 3 Fine lake sand do with Ottawa sand 1 Western gypsum cement 3 Fine lake sand do with Ottawa sand do with fine lake sand do with Ottawa sand 1 Eastern gypsum cement 3 Fine lake sand do with Ottawa sand do .with fine lake sand do with Ottawa sand Western gypsum block mortar do do do do do Eastern gypsum block mortar do do . do . do do do do Based on total weight of dry materials in mixture. TABLE 29. See page 369. 372 APPENDIX D O I SS . . oo S Sdo'dd S S S Sow >, >>.2.2 >>>>>> >>.2.2.S.3 >> >> o -^ oo us o o o to cq - ddddoooooo o-< d dddd N M M M < * < ^* c< ^< es eo c^ eo N co e^ cs 2 : ! ! : OQ OQ % i s TABLES OF AUXILIARY TESTS OF MATERIALS 373 TABLE 31. COMPRESSIVE STRENGTH OF HOLLOW CLAY TILE Tile units are 12 in. wide and 12 in. long, except as noted Sample No. Kind of Tile Porosity, Percent of Volume Absorption, Percent of Dry Weight How Tested Area under Load, Sq. In. Maximum Load Nominal Thickness, In. Clay Total, Lb. Lb.per Sq. In. A-l A-2 A-3 Average A-4 A-5 A-6 Average A-16 A-19 A-20 Average A-ll A-l 2 A-14 Average B-fl B-8 B-10 Average B-l B-2 B-4 Average B-12 B-14 B-l 9 Average B-ll B-l 3 B-17 Average C-l C-5 06 Average C-2 C-4 C-8 Average C-13 C-14 C-19 Average C-15 C-l 8 Average 2 2 2 2 2 2 4 4 4 4 4 4 Surface clay, Chicago district do 40.3 44.4 43.1 42.6 44.5 43.7 41.9 43.4 MA" 29.0 28.5 27.3 28.3 28.5 27.7 26.2 27.5 On end . 19.6 19.6 19.6 16.2 16.2 16.2 25.2 25.2 25.2 16.0 16.0 16.0 44300 46860 44650 45277 18920 32110 22340 24456 53000 57280 63460 57913 29320 20250 33190 27588 52830 48400 62450 54560 52450 58150 58040 56213 134350 111400 160930 2260 2390 2280 2310 1170 1980 1380 1510 2100 2270 2520 2296 1830 1270 2070 1723 5800 5310 6860 5990 4480 4970 4960 4796 4740 3920 5910 4856 4460 4560 4020 4346 6980 8770 6410 7386 6150 4200 4190 4846 7400 6090 5760 6416 6060 3680 4870 do do . . On edge do do do do On end... do . do do do 27.6 do On edge do do do 44.2 42.9 41.8 42.9 28.8 27.3 27.9 28.0 30.0 28.6 31.0 29.8 30.8 32.4 25.6 29.6 28.8 28.0 29.8 28.8 15.5 15.4 2.5 ITS 18.3 18.5 16.9 17.9 18.5 17.6 18.5 18~2 16.0 28.1 29.5 26.0 27.5 15.0 15.0 14.2 I 14.7 16.0 15.0 16.6 15.8 16.4 17.6 12.8 do do 2 2 2 Surface clay, Boston district On end 9.1 9.1 9.1 do do . 2 2 2 do do do On edge. . . 11.7 11.7 11.7 do . do 4 4 4 do do . On end.... do do 28.4 28.4 27.2 do 15.6 15.0 14.6 15.6 15.1 7.3 7.0 11.2 8.5 8.8 8.8 7.9 ~sl 9.0 8.6 8.9 8.8 8.4 135560 68170 69760 56710 64880 98350 123500 94280 105376 68870 47040 46920 54276 123610 104850 96050 108170 58180 36780 47480 4 4 4 do On edge 15.3 15.3 14.1 do do do . do 2 2 2 Ohio semi- fire clay do do On end... 14.1 14.1 14.7 do . do 2 2 2 do On edge do 11.2 11.2 11.2 do do do 4 4 4 do On end 16.7 17.2 16.7 do do . do do 4 4 do do On edge do 9.6 10.0 * Nominal width of tile, 6 in. 374 APPENDIX D TABLE 31. COMPRESSIVE STRENGTH OF HOLLOW CLAY TILE Concluded Tile units are 12 in. wide and 12 in. long, except as noted Sample No. Kind of Tile Porosity, Percent of Volume Absorption Percent of Dry Weight How Tested Area under Load, Sq. In. Maximum Load Nominal Thickness, In. Clay Total, Lb. Lb. per Sq. In. D-l D-3 D-9 Average D-2 D-5 D-8 Average D-ll D-l 6 D-l 7 Average D-13 D-14 D-19 Average *E~5 *E-6 *E-8 Average *E-1 *E-2 *E-10 Average E-15 E-17 E-19 Average E-12 E-13 E-14 Average tF-5 tF-8 tF-10 Average tG-3 Average tH-1 tH-2 |H-4 Average 2 2 2 Ohio shale. . . do do 8.1 22.1 14.3 14.8 16.2 12.2 8.2 12.2 12.0 11.3 12.2 11.8 16.3 13.8 9.6 13.2 28.3 30.4 3.5 10.8 7.2 7.1 7.4 5.5 3.6 5.5 5.2 4.9 5.5 ~2 7.4 6.5 3.8 5.9 17.2 17.1 On end... do do On edge do 14.3 14.1 14.5 11.1 10.7 11.1 19.9 19.1 19.9 11.7 11.7 11.5 12.1 12.1 12.1 15.6 15.9 15.9 21.6 21.6 21.6 114350 112600 109680 8000 7990 7560 7850 3900 5800 7340 5680 9720 7950 8930 3866 8190 5220 10230 7880 4400 4210 4600 4402 2160 1820 1450 1810 4440 3460 4000 3966 3170 1980 1590 112210 43300 61980 81450 62243 193550 1/51770 177940 2 2 2 4 4 4 4 4 4 do . do do do On end... do do do do do On edge do 174420 95840 61130 117790 91686 53240 51040 55620 53313 33670 29000 23100 28590 95650 74660 86250 85520 39900 24920 20050 do do do do On end... do 2 2 2 Semi-fire clay, New Jersey district do . . 2 2 2 4 4 4 4 4 4 2 2 2 do . do do do do . 33.2 33.5 35.8 34.1 25.3 33.6 29.5 29.4 29.0 33.2 33.9 32.0 37.6 41.8 45.3 41.5 49.1 50.2 40.2 46.5 51.2 46.9 41.4 46.5 19.8 19.6 22.0 20.4 14.2 20.6 17.2 17^3 16.2 19.8 20.4 15.4 23.2 27.0 30.4 23.8 27.6 39.1 26.4 31.0 39.0 34.3 27.7 33.3 On edge.... do do On end do do do do do do Porous semi- fire clay. New Jersey district On edge do do 12.6 12.6 12.6 18.9 19.9 18.3 24.6 23.9 23.9 On end... do 28290 83270 54200 72630 70033 38060 33370 53440 41623 27150 32110 40300 33086 2246 4410 2720 3970 3700 1550 1400 2230 1726 1360 1780 1940 1693 do do do do 2 2 2 2H % 2i4 do . do do do do do do do do 19.9 18.0 20.8 'Nominal width of tile, 8 in. fCurved tile. TABLES OF AUXILIARY TESTS OF MATERIALS 375 TABLE 32. TRANSVERSE STRENGTH OF HOLLOW TILE Tile tested flatwise on side with center load and supports 10 in. apart. Tile units are 12 in. wide, except as noted. Sample No. Kind of Tile Maximum Load, Lb. Calculated Maximum Stresses, Lb. per Sq. In. Nominal Thickness, In. Clay Bending, Outer Fiber Shear. Center of Webs A-7 A-8 A-9 A-10 Average 2 2 2 2 Surface clay, Chicago district 1120 1050 830 1100 1025 2600 1500 2500 1890 2122 1000 1520 1280 1240 1260 5600 6900 5100 5250 5712 1220 2040 1630 2120 2530 1630 3200 2452 4530 6250 4910 3280 4742 1410 1100 1255 2010 1900 1330 2570 1952 395 370 292 387 361 254 147 244 185 207 625 950 800 775 787 547 675 499 513 558 477 798 637 321 945 608 1194 916 564 778 611 408 590 705 550 627 272 257 180 347 264 158 148 117 155 145 146 84 140 106 119 202 307 258 250 254 253 312 231 237 283 236 394 315 223 415 267 525 402 320 441 346 231 335 155 121 138 142 134 94 182 140 do do . do A-13 A-15 A-17 A-18 4 4 4 4 do . do do . do *B-3 *B-5 *B-7 *B-9 2 2 2 2 Surface clay, Boston district do do . do B-15 B-16 B-13 B-20 4 4 4 4 dc do do do C-7 C-10 2 2 Ohio semi-fire clay do C-20 D-4 D-6 D-7 Average 4 2 2 2 do Ohio shale do do D-12 D-15 D-18 D-20 4 4 4 4 do do do do tE-3 tE-4 2 2 New Jersey semi-fire clay do E-ll E-16 E-18 E-20 Average 4 4 4 4 do do do do 'Nominal width, 6 in. t Nominal width, 8 in. 376 APPENDIX D TABLE 33. TEMPERATURES OP VITRIFICATION AND FUSION OF CLAY TILE AND BRICK No. CLAY Temperature of Vitrification, Deg. C. Temperature Producing Softening, Deg. C. Temperature of Fusion, Deg. C. \ Surface clay, Chicago district 1120 1200 1240 B Surface clay Boston district 1120 1160 1180 c Ohio semi-fire clay 1180 1450 1460 j) Ohio shale 1120 1380 1400 E F New Jersey semi- fire clay partition tile New Jersey porous semi-fire clay, 2 by 8-in. curved tile 1200 1480 1450 1500 1470 G New Jersey porous semi-fireclay, 2 by 12-in. curved tile 1510 1530 H New Jersey poroua semi-fire clay, 2)4 by 11-in. 1450 1470 J Chicago common brick 1145 TABLE 34. POROSITY AND ABSORPTION OF CHICAGO COMMON BRICK Brick No. Specimen No. Porosity, Percent of Volume Absorption, Percent of Dry Weight 1 1 35.4 20.2 1 2 31.9 17.8 1 3 32.5 18.0 4 31.5 17. 5 M.i 13. 6 36.3 20. 7 26.5 15. . 8 24.3 12. j Average 30.4 ifi o 2 1 43.1 10. y 26.8 2 2 42.1 26.9 2 3 40.1 24.4 2 4 39.9 24.4 2 5 40.3 24.7 2 6 40.9 25.1 2 7 40.3 24.6 2 8 40.6 24.9 2 Average 40.9 25 1 TABLES or AUXILIARY TESTS OF MATERIALS 377 TABLE 35.-COMPRESSIVE STRENGTH OF CHICAGO COMMON BRICK Sample No. How Tested Dimensions, In. Area Under Load, Sq.In. Maximum Load Width Thick- ness Length Total, Lb. Lb.per Sq.In. J-l On end . . . 3.45 3.75 3.50 2.20 2.25 2.25 7.59 8.44 7.88 32900 14900 27550 4330 1760 3500 3200 1160 3610 1240 1740 1980 2020 1960 3030 3460 2050 1810 4100 2440 2815 J-2 do J-4... do Average J-3 Vt brick On edge. 2.25 2 15 2.35 2.35 2.25 2.25 . 2.9 3.35 5.40 4.10 3.40 4.55 6.52 7.20 12.69 9.64 7.67 10.24 7550 26000 15680 16800 15150 20700 J-5 do J-7 do do . do J-8 do J-9 do do do J-10 do do ' Average J-3 J^ brick On side. . . 3.70 3.50 3.60 3.50 3 60 3.65 .... 4.10 4.60 7.80 2.60 4.60 3.70 15.17 16.10 28.08 9.10 16.56 13.50 46010 55800 57730 16490 67910 32900 J-5 do do . J-8 do .... do do J-7 do J-9 do . do . J-10 do do Average TABLE 36. TRANSVERSE STRENGTH OF CHICAGO COMMON BRICK Brick tested on side with center load and supports 7 in. apart Sample No. Dimensions, In. Maximum Load, Lb. Modulus of Rupture, Lb. per Sq. In. Width Thickness J-3 3.70 3.50 3.70 3.60 3.65 2.25 2.15 2.35 . 2.25 2.25 940 2700 460 1540 1580 530 1750 240 890 900 862 J-5 J-8 J-9 J-10 Average 378 APPENDIX D TABLE 37. POROSITY OF GYPSUM BLOCK Sample No. Kind of Block Porosity, Percent of Total Volume Thickness Gypsum K-4 4-in hollow Western .. do 63.7 63.7 63.7 63.9 63.6 63.6 63.7 58.6 58.4 62.6 62.2 60.4 K-5 4-in. hollow 4-in. solid L-4 L-5 do 4-in. solid 2-in. solid do do . M-4 M-5 2-in. solid do Average N-4 : N-5 4-in. solid 4-in. solid Eastern do . do O-4 O-5 2-in. solid 2-in. solid do Average TABLE 38. COMPRESSIVE STRENGTH OF SOLID GYPSUM BLOCK All blocks tested on edge Sample No. Gypsum Dimensions, In. Area Under Load, Sq. In. Maximum Load Thickness Length Width Total. Lb. Lb. per Sq. In. L-l Western . . . do do 4 4 4 30.1 30.1 30.0 12 12 12 120.5 120.5 120.0 61100 44300 49080 507 367 409 428 640 396 398 478 656 498 504 553 458 365 415 413 L-2 L-3 Average M-l... M-2 M-3 Average . . . do 2 2 2 29.9 29.9 30.0 25.7 25.7 26.2 12 12 12 16.5 16.5 16.5 59.8 59.8 60.0 103.0 103.0 105.0 38250 23760 23840 67540 51340 52860 do do N-l N-2 Eastern do do 4 4 4 N-3 Average 6-1... 0-2 O-3 Average do do do 2 2 2 26.1 26.1 26.1 16.5 16.5 16.5 52.2 52.2 52.2 23950 19205 21685 TABLES OF AUXILIARY TESTS OF MATERIALS TABLE 39. TRANSVERSE STRENGTH OF SOLID GYPSUM BLOCK All blocks tested flatwise on side with center load 379 Sample No. Gypsum Dimensions, In. Span, In. Weight of Block, Lb. Maximum Load, Lb. Modulus of Rup- ture. Lb. per Sq. In. Thickness Length Width L-7 L-8 I.-9 Western . . . do .... do .... 4 4 4 30.2 30.2 30.2 12 12 12 24 24 24 42.9 47.4 46.2 689 652 562 132 125 109 122 206 201 227 211 175 165 169 170 143 117 146 135 Average . M-7 M-8 do .... do .... do .... 2 2 2 29.8 29.9 29.9 12 12 12 24 24 24 22.7 22.1 22.8 266 260 294 M-9 Average. . N-7 N-8 N-9 Eastern do .... do .... 4 4 4 26.1 26.1 26.0 16.5 16.6 16.6 20 20 20 58.9 56.2 58.2 1520 1433 1503 Average. . O-7 O-8 do .... do .... do .... 2 2 2 25.9 26.2 25.9 16.4 16.3 16.4 20 20 20 24.4 27.7 25.7 305 245 311 O-9 Average TABLE 40. TRANSVERSE STRENGTH OF GYPSUM WALL BOARD Samples, 18 in. long, were tested with center load and supports 16 in. apart No. Width, In. Thick- ness, In. Weight, Lb. Condition of Board Direction of Loading Bar Maxi- mum Load, Lb. A-l 11 9 38 3 1 Drv Parallel with grain of paper 37 A-2 . . . 12.0 39 3 1 Dry do 39.0 A-3 12 39 3 1 Drv do 37 5 Average 37 8 B-l . . . 12.0 0.39 3 1 Dry after having been sat- Parallel with grain of paper 39.0 B-2 11 9 38 3 do 35 5 Average . 37.2 C-l.".. C-2. . 11.9 12 0.40 38 3.8 3 7 Saturated Saturated Parallel with grain of paper do 10.0 6.0 Average . 8.0 D-l... 12.0 0.38 3.1 Dry . . . Perpendicular to grain of 90.5 D-2 D-3 12.0 12 0.34 39 3.2 3 2 Dry Dry paper do 96.0 92 Average . 92.8 E-l E-2. . 12.0 12 0.38 38 3.0 3 1 Dry after having been sat- urated . . . . Perpendicular to grain of paper 89.5 87.0 Average 88 2 F-l 12 38 3 7 Saturated . Perpendicular to grain of 15.5 APPENDIX E PREVIOUS INVESTIGATIONS Page 1. Bauschinger's Tests 381 (a) First Series 381 (b) Second Series 382 2. Tests by Moller and Liihmann 383 3. Hamburg Tests 385 (a) First Series 385 (b) Second Series 386 (c) General Results 386 4. Fire Test of Column at Vienna 386 5. New York Tests 387 6. Waite's Tests 388 7. Tests by McFarland and Johnson 388 38U APPENDIX E PREVIOUS INVESTIGATIONS The first experimental investigations on the fire resistance of building columns were made abroad, principally in Germany. When iron came into use as a structural material in that country it was thought that the possi- bility of constructing truly fireproof buildings was realized, for iron is not combustible. Extensive fires showed however, that, while the structural framework did not burn, the building collapsed suddenly and without warn- ing. It was early recognized that some wooden structures offered greater resistance to fire than those built of unprotected iron, a result that occa- sioned no little comment when first observed. In fact iron as a structural material was for a time in considerable disrepute. At one time, the use of unprotected cast iron columns under main bearing walls was forbidden in Berlin, but wrought iron columns permitted. Subsequent to large fires in Berlin and Hamburg the reverse was true. Similar changes in opinion were evident as to whether cast and wrought iron columns should be given fire protective coverings and whether such coverings should be removable or permanent. 1. BAUSCHINGER'S TESTS* In 1884-86 Prof. J. Bauschinger of Munich, Germany, made two series of fire and water tests on building columns that were loaded in a horizontal testing machine and heated by wood fire in a wrought iron trough placed under them. Water was applied to the top surface. Temperatures were measured by alloys of tin, lead, and silver having computed melting points of 300, 400, 500 and 600 C, that were attached to rods and held against the surface of the column at the middle of the sides to obtain the average tem- perature. Deflections were measured in the vertical and horizontal direc- tions by indicators attached to wires that were fastened to the column at the middle of its length. The columns were loaded to what were considered safe working loads and subjected to three successive fire and water tests, the surface temperatures it was aimed to attain when water was applied being generally 300C, 400 to 600C, and red heat above 600C. These tests were made with the column ends fixed or restrained. If failure did not occur a final test at red heat with the column ends unrestrained was made in most cases. The method of testing was largely determined by the fact that opin- ions differed as to whether damage to cast irpn columns in building fires was caused by the fire or by the application of water to the red hot metal. During the first part of each test the column deflected downward toward the fire due to the unequal heating, but with increase of temperature greater uniformity obtained and the column straightened somewhat. The applica- tion of water to the upper surface caused another sharp deflection downward which became less as the column cooled on all sides, the final deflection be- ing in some cases upward. The test conditions and effects approximate to some extent those pertaining to unprotected columns under exterior walls. (a) First Series In the first series, tests were made on six cast iron, three wrought iron and 15 columns, of other building materials including Portland cement mor- tar, brick and several kinds of building stone. The cast iron columns had been rejected for building purposes because of uneven wall thickness, "cold shuts" and other defects and were more or less ornamental in form, the types varying from the plain cylindrical and slightly tapering shafts to the form having an ornamental base for about one-third of the length and a tapering shaft, which in one case was deeply *Mittheilungen aus den Mech. Tech. Lab. d. k. Tech. Hochschule, Munchen, Heft 12, 1885; Heft. 15, 1887. 381 382 APPENDIX E fluted. They had plain or highly ornamental capitals and were from 11 ft. to 13.8 ft. in length, and from 5.8 in. to 7.6 in. in outside diameter, as measured at the mid-height of the column, with average wall thicknesses of 0.40 in. to 1 in., the thickness varying considerably within each column. Working loads of 3400 to 5800 lb. sq. in. were applied, the stress de- pending on the slenderness ratio of the column. As tested with restrained ends the cast iron columns supported their full load in the fire and water tests although cracks developed in some cases at the higher temperatures when water was applied. Maximum vertical deflections of Z l / 2 in. were observed after application of water on columns of nearly uniform wall thickness. With columns of uneven wall thickness the deflections were larger. In the tests with unrestrained ends, on appli- cation of water, the resulting deflection made the columns unable to support full load, and caused some of them to break. The wrought iron columns were about 13 ft. (4 meters) in length and consisted of one welded tube 5.04 in. outside diameter and 0.24 in. thick, and two built-up box columns, one of two 7-in. channels and two plates fastened together by bolts spaced about 16 inches on centers, and the other of two 7-in. I-beams and two plates fastened with bolts spaced about seven inches apart. The loads were 6200, 7600 and 6700 lb. sq. in., respectively. The welded tube took a large deflection before the temperature had reached 600 C. and failed to sustain full load. A slight application of water increased the deflection and caused it to fall out of the machine. The two other columns were heated to 300 and 400 C. followed in each case by water application, their behavior being similar to that of the cast iron columns, only the deflections were larger. On heating to 600 C. and applying water the deflections became so large that the full load could not be carried and some of the bolts were sheared off. Of the tests on other building materials that with Portland cement mor- tar was made on a column about twelve inches (30 cm.) square and ten feet (3 meters) long. The proportion of the mixture was 1:5, Portland cement and coarse sand. The column was tested at the age of 6]/ 2 months under a working load of 95 lb. per sq. in. It was heated for lf hr. until a tempera- ture of 600C. was attained at the middle of the sides when water was ap- plied. No apparent injury resulted and when cold it was loaded to failure at 920 lb. per sq. in. The brick column was about 12^ inches (32 cm.) square and 6.6 feet long with brick laid in Portland cement mortar and the outside covered with a layer of Roman cement plaster about 0.60 inch (1. 5 cm.) thick. It was exposed to fire for one hour attaining a temperature of 600C. on the sides, when . water was applied. No apparent damage other than slight cracking and flaking of the plaster resulted, the column being subsequently loaded to failure at load of 520 lb. per sq. in. (b) Second Series Objections raised against Bauschinger's tests, in particular that the loads applied to the cast iron columns were too small and that the component parts of the wrought iron columns were bolted together at intervals too far apart to secure a rigid section, led Bauschinger to conduct a series of tests in 1886 on two cast and five wrought iron Columns. The cast iron columns were about 13 feet (4 meters) long; one had outside diameter of 7 in. and average wall thick- ness of 1.1 in. and the other had outside diameter of 6.1 in. and average wall thickness of 1 in., the applied working loads being 8400 and 7100 lb. per sq. in., respectively. The columns had fairly uniform wall thickness and were ap- parently of better quality than the cast iron columns of the first series. They were tested in a manner similar to those in the first series and although large deflections occurred when heated to red heat and suddenly cooled by water application, they sustained their full working load. No cracks, due to water application developed. The wrought iron columns were about 19 feet long and consisted of two plate and channel box sections and three starred angle sections. The former were built up of two 5.7-in. channels and two 5/16 by 8-in. (20 cm.) PREVIOUS INVESTIGATIONS 383 plates with rivets spaced 3 to 5 in. on centers, and were loaded to 6,300 Ib. per sq. in. The starred angle sections were of two sizes, two being built up of four 3 l / 2 by 3]/ 2 by 7/16-in. angles spaced 2 l /$ in. back to back and riveted together rigidly at the ends and at two intermediate points about six feet apart The angles of the third column of this type had Z l /% by 3^ by ^i-in. (1.0 cm.) angles spaced 1.4 in. back to back and were riveted at the end and at five intermediate points, about three feet apart. The working loads for the two types were 6300 and 5300 Ib. per sq. in., respectively. All five columns were heated red hot and water applied until they were cold. The two box columns carried their full load throughout the test, al- though large permanent deflections were produced. The angle columns de- flected downward rapidly and were unable to carry their full load at 600 C. Water application increased the deflection and caused a further decrease in the sustained load. The rivets were distorted but none were sheared off. 2. TESTS BY MoLLER AND LtfHMANN* In 1887, M. Moller, a government architect and R. Liihmann, an engineer, obtained a prize offered by the (German) Society for the Promotion of In- dustrial Progress for the best essay on the subject of the Resistance of Iron Columns when Subjected to High Temperatures, submitting to that end a paper in which were described tests conducted by them at Hamburg, Ger- many. From the remarks accompanying the announcement of the competition it is evident that the principal interest centered in the relative resistance to fire and water of unprotected cast and wrought iron columns, although the behavior of masonry piers at high temperatures was also considered of im- portance. In planning their investigation, Bauschinger's work was carefully con- sidered by Moller and Luhmann, who concluded that in both the first and second series of tests by the former, the wrought iron columns were over- loaded, resulting in relatively greater bending as the columns deflected un- der the unsymmetrical heating and giving greater extreme fibre stress than the columns could withstand. It was held that a comparison of cast and wrought iron columns should be made with specimens identical in length, lateral dimensions and moment of inertia. The specimens tested by Moller and Luhmann were 3.28- ft. (one meter), 6.56 ft. (2 meters) or 13.12 ft. (4 meters) in length. The shortest length was chosen to give approximately the compressive strength of the material, the intermediate length was in about the same ratio to the lateral dimensions as of columns in actual use, and the longest was taken as representing un- usually large values of that ratio. The cast and wrought iron specimens, all of approximately 9.8 square inches in cross sectional area, comprised solid and hollow cylindrical forms, the former 3^2 in. in diameter, the latter about six inches in outer diameter with wall thickness slightly less than fy% in.; a hollow cast iron ornamental fluted column of approximately the same diameter and area as the other hollow sections; and a riveted form of rectangular section (6 by 7 in.) built up of four angles united on two sides by plates and on the other sides by lattice bars, the component parts being rigidly bolted and riveted together. The cast iron columns had fairly uniform wall thickness. As adding somewhat to the resistance to fire and water, one of the wrought iron and two of the cast iron columns were filled with cement, a 2-in. gas pipe being placed concentrically in one of the latter to maintain alignment of the pieces when the column broke. Quite full protection was given one each of the hollow cast and wrought iron specimens by a covering of 1:3 cement mortar about 2 l / 2 inches thick, interlaced with wire. Also, one of the riveted angle columns was protected by a circular wood mantle about \y^ inches thick, covered with sheet iron. *Verhandhmg des Vereines zu Beforderung des Gewerbfleisses, Vol. 66, 1887, pp. 573 and 701. 384 APPENDIX E There were further included oak and fir columns 6 in. square, and col- umns of brick 9 in. square, set in cement mortar. Lengths other than 6.56 ft. were used only in the unprotected cylindrical cast and wrought iron specimens. Report was made on about 40 tests of which approximately two-thirds were fire and water tests, the rest being load tests at normal temperature. The testing apparatus was very similar to that used by Bauschinger, tfie columns being loaded in a horizontal hydraulic press, and heat applied by coke fire jn a U-shaped trough placed beneath the column. Temperatures of 330, 440 and 600C. were measured by metals and alloys placed in contact with the outside of the columns. Vertical deflections were measured at the mid-point of the length, using a lever with one of its ends resting on the column. The loads were applied with the column axis uniformly 0.39 in. (one cm.) below that of the machine, the authors holding that central loading of columns does not occur in buildings except by chance, and that the above eccentricity is about what may be expected in practice. In general the tests were conducted with the column ends unres- trained, the machine being fitted with spherical bearing blocks, but to determine the difference a few columns were loaded between fixed parallel bearing plates. Some of the columns were loaded at ordinary temperatures, and the safe load, as judged apparently by the limit of permissible deflection, and the maximum load, were determined. The same quantities were deter- mined for the high temperature condition, in general after 330C. and 600C. had been attained on the upper and lower sides of the column, respectively. The load determinations at high temperature were generally made when the maximum deflection had been induced which generally occurred at the time of water application. On application of maximum load while hot, the short hollow columns (one meter long) deflected upward due to yielding of the metal at higher temperature on the lower side of the column. The solid columns of this length, in common with all of the longer columns, deflected downward due to the uneven heating, the deflections increasing on application of water and load. The following tabulation gives a summary of the result obtained with unprotected hollow and solid columns of cast iron and wrought iron: Slenderness, pj r e an( j wa ter test Test at normal temperature _. . ratio, Maximum Maximum Effective L load, Lb. per Deflection, load, Lib. Deflection, Form and Material, length, Ft. r sq. in. In. per sq. in. In. Hollow cast iron.... 4.2 27 16500 0.98 43700 1.02 Hollow wrought iron 4.2 27 13500 1.97 Hollow cast iron 7.5 47 23000 1.77 37200 0.39 Hollow wrought iron 7.5 47 10800 1.97 23000 0.78 Solid cast iron 4.2 57 9220 1.17 39300 0.33 Solid wrought iron.. 4.2 60 9100 0.28- 22100 0.63 Solid cast iron 7.5 101 6640 1.93 10900 0.98 Solid wrought iron.. 7.5 107 5000 1.97 13500 0.18 Hollow cast iron.... 14.0 89 2650 4.75 15300 1.77 Solid cast iron 14.0 190 1890 6.80 Solid wrought iron . . 14.0 201 1620 4.56 The decrease in strength with length was marked, particularly for the columns loaded after fire exposure and water application. This was due to the larger lateral deflections caused by unsymmetrical heating, cool- ing and loading induced in the longer columns, test conditions that can hardly be said to duplicate typical fire conditions even for unprotected ex- terior wall columns. In the snorter lengths, the cast iron sustained higher average unit loads than the wrought iron, the difference becoming smaller with increase of length or slenderness ratio. The load reported as safely carried after fire and water application varied from a little over one half of the maximum load finally sustained to nearly the full value of the latter. Failure was due in all cases to bending produced mainly by uneven tempera- ture distribution over the column section. The tests developed no crack- PREVIOUS INVESTIGATIONS 385 ing of the hot cast iron due to water application except in the case of the longest column in which case the crack could have been incidental to failure as caused by the large deflection. The columns tested between fixed parallel plates withstood higher loads than those tested with spherical end blocks, although the tests were too few in number to afford definite comparison. The filled columns sustained slightly higher loads under the same test conditions than the corresponding unfilled columns. The metal of the columns protected by mortar was only moderately warm after the column had been in the fire about \ l / 2 hours, and that of the column protected by wood was 120C. after the covering had been removed subsequent to a 63-min. fire exposure. The strength of the brick columns was reduced about 50 percent after 40 to 45-minutes fire exposure. The oak column failed due to reduction of area and strength of the wood after 8 min. under load of 1240 Ib. per sq. in., as computed on the original area, and the fir column after 18 min. in the fire under load of 1110 Ib. per sq. in. 3. HAMBURG TESTS* Two series of fire tests on loaded building columns were undertaken at Hamburg, Germany, in the period 1893 to 1895 by representatives ap- pointed by the Hamburg senate from the building commission, the fire department, the warehouse association and the insurance interests. (a) First Series In the first series, tests were made on wrought iron columns built up of 4 angles united by latticed bars and plates to form rectangular sections. A few columns were tested unprotected, two were filled with cinder concrete and nine were protected by coverings from ^ in. to 2 in. in thickness, con- sisting of concrete (Monier) blocks, gypsum and magnesite blocks or boards, pressed cork and asbestos-cement. Some of the coverings were protected by a sheet metal mantle. In the series were also included three wooden columns 11.8 in. square, one of which was covered by sheet metal. The question of the relative fire resistance of the several column ma- terials was still of interest and although fire protective coverings had come to be employed, their use had not gained such headway as in America, where hollow tile, at that date not manufactured in Germany, was the almost universal covering material. The importance of simulating in the tests actual loading and fire conditions was recognized. The columns were loaded by a hydraulic ram in upright position within a framework in which were inserted two platforms \\ l / 2 ft. apart to which the test column was attached. Heat was applied over a length of about four feet in the middle portion of the column by a gas-fired oven built in halves which swung together about the column. Temperatures were measured by Seger cones, fusible alloys and a thermo-electric pyrometer, and lateral deflections with rods passed through holes in the furnace walls. Work- ing load was applied, centrally or eccentrically, and heating continued until the column was unable to sustain it, when water was applied over the heated length. The furnace temperature rise varied considerably between dif- ferent tests and was at times quite rapid, 1200C. being sometimes attained in 2 hr. and 1400 C. in 4 hr. The unprotected wrought iron columns of the first series failed after 17 to 59-min. fire exposure, depending on the rate of temperature rise, the metal temperature at failure being given at about 600 C., and the load sus- tained, 14,200 Ib. per sq. in. (1000 kg. per sq. cm.). The filled columns prov- ed to be only slightly more resistive than the unprotected and unfilled columns. *Vergleichende Versuche uber die Feuersicherheit von Speicherstutzen. Commissions- ""VergleicKnde^Ube/s'icht uber die Feuersicherheit gusseiserner S'peicher-stutzen. Ham- burg, 1897. Zeitsch _. _ Stahl und Eisen. Vol. 18. p. 691 ? Zeitschrift d. Verem Deutch Ing., Vol. 40, p. 159, Vol. 41, p. 1007, Vol. 42, p. 183. 386 APPENDIX E The protected wrought iron columns failed after l-K to 4 hr., with maximum furnace temperature of 1200 to 1300C., the load applied being apparently the same as for the unprotected columns. The temperatures inside of the column were not known, except that they were over 412 C. The application of water resulted in injury to the concrete coverings, and destruction of the other coverings except where covered with sheet metal. The wooden columns failed after a furnace exposure averaging a little over one hour for the three tests, the reduction in cross section from com- bustion of the wood being about 40 per cent. (b) Second Series Tests were made on about 24 columns of cast iron of 10.8 in. outside diameter, 22 of which had wall thicknesses of 1.18 in., and two, 0.47 in., the columns being cast in vertical position. Of the total number, 17 were pro- tected by coverings \ l / 2 to 2 in. (4 to 5 cm.) thick, consisting of the ma- terials used in the first series to which were added coverings of tufa stone and asbestos-kieselguhr. A number of the coverings were encased in sheet metal. The effect of an air space between the covering and column and of free convection within the column were studied, as also, the difference be- tween permanent as distinguished from removable coverings, some members of the commission holding that coverings should be removable to permit ex- amination of the column from time to time, on account of danger from rust. The method of testing was substantially the same as in the first series. The unprotected cast iron columns failed in from 35 to 59 min. depending on the intensity of the fire, under load of 7100 Ib. per sq. in. (500 kg. per sq. cm.), and temperature of the column reported as 800 C. Increasing the col- umn load to 10,700 Ib. per sq. in. (750 kg. per sq. cm.) caused failure to occur with column temperature of 700 C. The thin walled column gave a little lower resistance than those of greater thickness. The application of water to unprotected columns that had failed in the fire test and suffered large de- formation, generally caused cracking. The protected columns failed after 3 to 5 l / 2 hr. with maximum furnace temperatures from 1200 to 1500 C., except the one covered with 2-in. thick- ness of asbestos-kieselguhr, which did not fail after a fire exposure of 7 hr. The air space between the column and the covering increased the fire resistance a little and the provision for free convection within the column delayed failure by nearly one hour. The action of water on the coverings was the same as in the first series. (c) General Results The Hamburg tests were the first to determine the strength of wrought iron and cast iron, applied as columns, under central load and symmetrical heating. The column temperatures reported, regarded as those of the metal at failure, were without doubt higher than the actual temperatures due to the methods of measurement employed. As column tests, they are open to ob- jection in that only about one-third of the column length was heated. The tests on protected columns, while giving little information on the effective- ness of covering materials now in use, proved conclusively the great gain in fire resistance attainable by protecting the metal with materials of low heat conductivity. With regard to water application on cast iron columns at high tempera- ture, the results are not conclusive, since in almost all tests, the columns had sustained large deformations by failure in the fire test before water was applied. 4. FIRE TEST OF COLUMN AT VIENNA* In 1893 the Building Department of Vienna conducted a fire and water test on a single wrought iron column 11^ ft. long, built up of two 5^-in. channels, connected by lattice bars. The column was protected by brickwork 5^2 iru thick, laid in fire clay mortar, the interior of the column being un- filled. The furnace was of brick, 8 by 12 ft. in horizontal dimensions, and with height equal to the column length. Wood, piled 3 to 4 ft. high, was used for fuel and the temperatures of furnace and column were indicated by alloys. Engineering News, Vol. 32, p. 184, September ^ 6, 1894. Translation of article in Zeitschrift des Oestereicheschen Ingen. u. Arch. Verein. PREVIOUS INVESTIGATIONS 387 Load was applied to the column section using a long lever. After a fire test of 2^2-hr. duration wherein furnace temperatures evidently much in ex- cess of 400 C. were attained, a hose stream was applied to one side of the column. The only apparent damage caused by the combined test was considera- ble spalling of the bricks at the corners, cracking of bricks in the upper half of the covering and washing away of some of the mortar. The maxi- mum temperature indicated inside of the column was 65C. 5. NEW YORK TESTS* Fire tests of unprotected columns, two of structural steel and two of cast iron, and a fire and water test of one unprotected cast iron column, were made in 1896 under the direction of a committee appointed by the Tariff Association of New York, the Architectural League of New York and the American Society of Mechanical Engineers. The steel columns were 14 ft. long, one being a box section built up of two 10-in. channels and two 12 by /4-in. plates and the other a Z-bar sec- tion consisting of four 4 by 5/16-in. Z-bars riveted to a plate 6% in. wide, other details of design being in accord with accepted standards of practice. The cast iron columns were 13 ft. long, of <-in. outside diameter and 1-in. wall thickness and were cast in horizontal position with dry sand core, the ends being flanged and end bearings machined. The columns were tested in vertical position within a furnace chamber about 12 feet square and 14 feet high, the fuel used being producer gas ad- mitted by burners extending through the floor of the furnace. Air was sup- plied through openings in the floor near the gas inlets. Arrangements were made for intensifying the fire when necessary by injecting a naphtha spray into the gas main supplying the burners. Load was applied to the column within a restraining frame of structural steel by a hydraulic ram placed be- neath the column, filler blocks of cast iron transmitting the load to the column. In the fire tests it was intended to subject the columns to working loads, and for one test each of steel and cast iron columns, to use a slow and a rapid furnace temperature rise. Furnace temperatures were measured with an Uhling-Steinbart transpiration pyrometer. Temperatures on the metal of the columns were not measured in any of the tests. In the test of the plate and channel column, using a slow temperature rise, a furnace temperature of about 650 C. was attained in 1 hr., which temperature maintained for about 20 minutes caused the steel to show red color and fail under a load of 6400 Ib. per sq. in., trouble with the loading equipment preventing the application of the full working load. The Z-bar column, tested under full working load of 12,000 Ib. per sq. in. and rapid furnace temperature rise, failed 25 min. after the beginning of the test. A maximum furnace temperature of about 750 C. was indicated at 14 min., which fell off to 600 C. at failure. The cast iron columns were tested under working load of 7700 Ib. per sq. in. In the test with slow temperature rise the column began to show color after 65-min. fire exposure, the furnace temperature being near 600 C. After another 18 min. during which the furnace temperature averaged 640 C. the gas was shut off and the furnace door opened for 9 min., which disclosed the test column to be decidedly red and bent. The door was closed and the test continued at lower furnace temperature for 28 min., the column sus- taining its load although greatly bent. No cracks developed. The per- manent lateral deflection was 3^2 in. The cast iron column tested with rapid temperature rise had deflected a .visible amount at 35 min. and began to show color at 39 min., the furnace temperature at this time being 730 C. It failed at 43 min. with complete fracture across the section near the middle. In the fire and water test, water was applied at four successive times following fire exposures of increasing intensity. Before the third application the furnace temperature was 580 C. and the column showed color Imme- diately before the last water application a furnace temperature of 700 L. Trans.~Am. Soc. of Mech. Eng., Vol. 18, 1&96-1897, p. 24. 388 APPENDIX E was indicated and the column was red and bent. No cracks developed. The permanent lateral deflection was 3J4 in. The tests made apparent that unprotected metal columns will fail in fires of moderate intensity after a comparatively short exposure, the steel columns being less resistive than those of cast iron under the respective unit loads for which the two types are generally designed. Injury to cast iron columns due to water application while hot is shown to be improbable with columns of the given proportions. The tests give little information on the temperature in the metal at failure or on definite time resistance under com- parable fire conditions. 6. WAITE'S TESTS In 1903 the Guy B. Waite Co. of New York conducted some fire and water tests on floors and partitions, under the supervision of the Manhattan Bureau of Buildings, constructing to that end a reinforced concrete test house in which were placed, for the purpose of studying incidentally the behavior of column coverings, a reinforced concrete column made with stone aggregate, proportion of mixture, 1:2:4, and two cast iron columns, one of which was covered with \ l / 2 in. of poured cinder concrete of proportion 1:5, Portland cement and hard coal cinders, the other with a gypsum ancTcinder composition. The reinforced concrete column was considerably pitted by water from a IJ^-in. nozzle at 60 Ib. pressure after it had been subjected for 4 hr. to a test fire with average temperature of about 930 C. The cinder concrete covering was in excellent condition after it had gone through the same test and in addition three tests of 1-hr, duration with water application at the end of each. The gypsum covering appeared in good condition at the end of a single fire test, but on water application it was partially washed away. 7. TESTS BY McFARLAND AND JOHNSON* Tests to determine the effect of fire and water on the strength of rein- forced concrete columns were made in 1906 by H. B. McFarland and E. V. Johnson at the Chicago laboratory of the National Fireproofing Company. The columns, three in number, about W l / 2 inches square and 12 feet long were made of 1:2:4 limestone concrete, and reinforced with ^j-in. rods placed near the corners. Two columns were tested in compression at normal tem- perature at age of 2 months and 3J^ months, respectively, and sections 5 to 6 feet long cut from them outside of the region of failure for use in the fire test. One of these specimens was covered with 3-in. solid porous clay tile and the other was tested unprotected, and after the fire test subjected to water application. The third column was cut in two, one part for use in the fire test, and the other for a comparable compression test at normal tem- perature. The age of all columns was 23 months at the time of the fire test. The three specimens were placed on end in a wood-fired furnace and subjected under no load to a 3-hr, fire test. Furnace temperatures, as indi- cated by a Bristol thermo-electric pyrometer, ranged from 800 to 1000 C. for the greater portion of the period. On the day following the fire test, they were tested in compression. The section protected by clay tile was little affected by the test and de- veloped compressive strength of 3127 Ib. per sq. in. An 18-in. long specimen cut from the same column but not subjected to fire test, developed 3558 Ib. per sq. in. The specimen to which water was applied after the fire test, failed in the compression test at 674 Ib. per sq. in. The column from which it was cut had developed 2116 Ib. per sq. in. at age of 3]/ 2 months, the fire and water treatment haying apparently caused a decided decrease in strength. A similar effect was indicated in the case of the third specimen, its strength being 7,11 Ib. per sq. in., against 2565 Ib. per sq. in. for the section of the same column that was not exposed to fire. The large reductions in strength sustained by the unprotected columns can be ascribed in part to their small size, larger columns being subject to smaller percentage reduction in strength due to surface damage from fire exposure. * Engineering News. Vol. 56. p. 316, September 20, 1906. APPENDIX F CENTIGRADE AND FAHRENHEIT CONVERSION TABLE c. 10 20 30 40 50 60 70 80 90 F. F.' F- F, F. F " F. F. L ' F. 32 50 68 86 104 122 140 158 176 194 100 200 300 212 392 572 230 410 590 248 428 608 266 446 626 284 464 644 302 482 662 320 500 680 338 518 698 356 536 716 374 554 734 400 500 600 752 932 1112 770 950 1130 788 968 1148 806 986 1166 824 1004 1184 842 1022 1202 860 1040 1220 878 1058 1238 896 1076 1256 914 1094 1274 700 800 900 1292 1472 1652 1310 1490 1670 1328 1508 1688 1346 1526 1706 1364 1544 1724 1382 1562 1742 1400 1580 1760 1418 1598 1778 1436 1616 1796 1454 1634 1814 1000 1832 1850 1868 1886 1904 1922 1940 1958 1976 1994 1100 1200 1300 2012 2192 2372 2030 2210 2390 2048 2228 2408 2066 2246 2426 2084 2264 2444 2102 2282 2462 2120 2300 2480 2138 2318 2498 2156 2336 2516 2174 2354 2534 1400 1500 1600 2552 2732 2912 2570 2750 2930 2588 2768 2948 2606 2786 2966 2624 2804 2984 2642 2822 3002 2660 2840 3020 2678 2858 3038 2696 2876 3056 2714 2894 3074 1700 1800 1900 3092 3272 3452 3110 3290 3470 3128 3308 3488 3146 3326 3506 3164 3344 3524 3182 3362 3542 3200 3380 3560 3218 3398 3578 3236 3416 3596 3254 3434 3614 2000 3632 3650 3668 3686 3704 3722 3740 3758 3776 3794 1 1.8 1 2 3.6 2 3 5.4 3 4 7.2 4 5 9.0 5 6 10.8 6 .56 Examples: 1.11 1.67 515C.- 950F.+9F. 059F. 2039F.-1110 C.+5 C.-1115C. 2.22 2.78 3.33 7 12.6 7 8 14.4 8 9 16.2 9 3.89 4.44 5.00 10 18.0 10 5.56 6.11 6.67 7.22 7.78 9.44 10.00 389 UNIVERSITY OF CALIFORNIA LIBRARY BERKELEY Return to desk from which borrowed. This book is DUE on the last date stamped below. E8 i '\ '.\L L; ^Uri ' ' MAR 27 LD 21-100m-7,'52(A2528sl6)476 YC 33238 800826 v UNIVERSITY OF CALIFORNIA LIBRARY