;-NRLF American Society of Municipal Improvements, 1915 Specifications for Creosoted Wood Block Paving [These specifications have not been adopted, but are printed for information and discussion at the convention at Newark, N. J., Oct. 9-13, 1916.] These specifications will be modified from time to time to keep them fully up to date. Suggestions as to modifi- cations or additions are solicited and should be sent to the Secretary, or to Ellis R. Button, City Hall, Minneap- olis, Minn., Chairman of the Sub-Committee on Specifi- cations for Wood Block Paving, and GEORGE W. TILLSON Boro Hall, Brooklyn, N. Y. Chairman of General Committee on Standard Specifications COPYRIGHTED, 1916 Any municipality which is represented in the membership of the society by one or more City Officials will be given free permission to use these specifications or any part of them upon application to the Secretary. PUBLISHED BY THE SOCIETY CHARLES CARROLL BROWN, Secretary 702 WULSIN BUILDING INDIANAPOLIS, INDIANA REPORT OF SUB-COMMITTEE ON WOOD BLOCK PAVING SPECIFICATIONS. The following specifications for wood block paving were presented by A. W . Dow, for the Sub-Committee on Wood Block Paving Specifications, to the Committee on Standard Specifications, and were presented as information, by the General Committee, to the Society on October 14, 1915. SPECIFICATIONS FOR CREOSOTED WOOD BLOCK PAVING. Timber. The wood to be treated shall be southern yellow pine, Norway pine, Douglas fire or tamarack. Only one kind of wood to be used in one contract. The blocks must be cut from a good grade of timber, and must be well manufactured, full size, square butted and square edged, free from the following defects: checks, unsound, loose or hollow knots, knotholes, worm holes, thru shakes and round shakes that show on the surface. In yellow pine timber there shall be not less than four (4) annual rings in any one inch measured radially from the pitch center. Wherever in any one inch there are less than six (6) annual rings to the inch, the summer wood shall average not less than 25 per cent. All measurements are to be made on a section of wood cut out per- pendicular to the grain. The blocks in each charge must average 80 per cent of heart wood, and no one block shall be accepted that contains less than 50 per cent heart wood. Size of Blocks. The blocks shall be from five to ten inches long, but shall average eight inches ; they shall be * inches in depth. They shall be from three to four inches in width, but in any one city block all of them must be of uniform width. A variation of 1/16 inch shall be allowed in the depth and width of the blocks from that specified. *NOTB. The committee recommends blocks 4 inches in depth for heavy traffic streets; blocks 3% inches in depth for medium to light traffic streets; for light traffic streets blocks 3 inches in depth may be used, but where 3-inch blocks are used no blocks shall be longer than 8 inches. Preservative. The preservative shall be wholly derived from coal gas tar or coke oven tar, and shall comply with the following requirements: 1st: The specific gravity shall be not less than 1.06 nor more than 1.12 at 38 C. 2nd: Not more than 3 per cent shall be insoluble by continuous hot extraction with benzol and chloroform. 3rd: On distillation which shall be made exactly as afterwards described, the distillate, based on water free oil, shall be within the following limits: Up to 210 C, not more than 5%, Up to 235 C, .not more than 30%, Up to 315 C, not less than 35% nor more than 70%, Up to 355 C., not less than 65%. 4th: The specific gravity of the distillate between 235 C., and 315 C., shall be not less than 1.02 at 38 C, compared with water at 15.5 C. The specific gravity of the distillate between 315 C. and 355 C. shall be not less than 1.08 at 38 C. compared with water at 15.5 C. 5th: The specific viscosity at 82 C., when taken in an Engler viscosimeter shall not exceed 1.3. The term specific viscosity shall mean the number of seconds found for the sample tested divided by the number of seconds for water at 20 C., as given in the official certificate for the viscosimeter used. 6th : The oil shall not contain more than 3 per cent of water. Oil samples taken by the inspector from the treating tank during the progress of the work shall at no time show an accumulation of more than 2 per cent of foreign matter, such as sawdust and dirt, and due allowance shall be made for all foreign matter, either water or material insoluble in benzol and chloroform, by injecting an addition- al quantity of oil into the block. Treatment. The blocks shall be treated in an air tight cylinder, with the pres- ervation heretofore specified. They shall first be subjected to live steam at a temperature between 220 F. and 240 F., for not less than two hours, after which they shall be subjected to a vacuum of 3 342937 not less than twenty inches and held for at least ten minutes. The temperature of the blocks shall be maintained between 150 F. and 240 F. While the vacuum is still on, the preservative oil, heated to a temperature of between 180 F. and 200 F., shall be admitted, and the pressure gradually applied to the cylinder until a sufficient amount of the preservative oil has been forced into the block. After this, if so desired, a supplemental vacuum, with or without steam, may be applied. At the completion of the treatment each charge of blocks shall contain not less than an average of 18 pounds of water-free oil per cubic foot of wood. Not more than 10 per cent in excess of the amount specified shall be allowed. The blocks after treatment shall show satisfactory penetration of the preservative, and in all cases the sap-wood must be thoroly treated thruout. To determine this, at least 25 blocks shall be cut up from each charge, and if more than 4 per cent of the blocks show un- treated sap-wood, the charge shall be retreated or rejected. After re-treating, the charge shall be again subjected to the same inspection. The surface of the blocks after treatment shall be clean and free from any deposit of oil or foreign substance. All blocks that are imperfect or that have been injured in the process of treating shall be rejected. Handling Blocks After Treatment. After the blocks have been treated and before they are laid, care must be taken to protect them as much as possible from drying out. They must at all times be closely piled when stacked on the street. All blocks must be thoroly wet, either while piled on the street before laying or while being laid, as directed by the Engineer. Inspection. All material and processes used in the manufacture of the blocks shall be inspected at the plant of the manufacturer, who shall equip his plant with all the necessary gages, appliances and facilities to enable the inspector to satisfy himself that the requirements of the specifications are fulfilled. He shall allow the inspector, or other authorized representatives, to inspect all material at all parts of the plant. 4 After delivery upon the street the blocks shall be subjected to a further inspection, and all imperfect blocks shall be rejected and removed from the street by the contractor. Foundation. The base shall be of concrete made in accordance with the speci- fications for concrete paving foundation and shall be* inches in thickness. At no place shall the surface of the finished concrete vary more than one-half inch from the given grade. The concrete foundation shall be cleaned and swept and shall be thoroly dampened immediately in advance of the spreading of the cushion course. .Cushion, (a) Mortar Bed. Upon the concrete foundation shall be spread a layer of dry mortar one inch in thickness and made of one part of Portland cement and three parts of sand, the intention being to produce a granular mixture which may be raked to the desired grade. Only sufficient water shall be added to this mixture to insure a proper setting of the cement. The dry mortar shall be thoroly mixed and shall be spread in place on the foundation by means of a template immediately in advance of the laying of the blocks, to such a thickness that when the blocks are set and properly bedded in the mortar their tops shall conform accurately to the finished grade of the roadway. Cushion, (b) Sand. Upon the concrete foundation shall be spread a cushion of sand, one ( 1 ) inch in thickness. The sand cushion shall be struck by templates to a surface parallel to the grade and contour of the finish- ed pavement in such a manner that when the blocks are set and prop- erly bedded in the sand, the tops shall conform accurately to the finished grade of the pavement. The sand used in this cushion shall all pass thru a quarter (^) inch screen and must contain between ten (10) and twenty-five (25) per cent of loam or clay. Laying the Blocks. Upon the bed thus prepared the blocks shall be carefully set with the fiber of the wood vertical, in straight parallel courses, generally *NOTE. The committee recommends that the concrete bed be at least 6 inches tn thickness and under heavy traffic 8 inches to 9 inches in thickness. at right angles to the curb, leaving a space next to the curb for the expansion joint*. The blocks shall be laid by setting them closely together on the mortar bed and no joint shall be more than J^" in width. Nothing but whole blocks shall be used except in starting a course, or in such other cases as the city may direct; and in no case shall the lap joint be less than 2". Closures shall be carefully cut and trimmed by experienced men. The portions of the block used for closures must be free from checks or other fractures and the cut end must have a surface perpendicular to the top of the block and cut to the proper angle so as to give a close, tight joint. After the blocks are placed they shall be rolled parallel and diagonal to the curb by a steam roller weighing between four and seven tons, until the surface becomes smooth and is brought truly to the grade and contour of the finished pavement. The rolling shall be completed before the mortar bed has set. All mortar that has set before the blocks are in place and rolled shall be discarded and replaced by fresh mortar. Filler, (a) Sand. After the rolling is completed, the joints between the blocks shall be filled by sweeping dry, clean sand into them, after which the surface shall be covered to a depth of about ^" with fine sand. This sand is to be left upon the pavement for such a time as may be directed by the city, after which it shall be swept up and taken away by the contractor. Filler, (b) Bituminous. After the rolling is completed, the joints between the blocks shall be filled with a bituminous filler, specified hereafter. The filler shall be brought to the proper temperature and poured into the joints; any filler on the surface of the pavemnt must be spread as thin as possible by means of squeegees. After the joints are filled, as prescribed, the surface shall be com- pletely covered by a thin coat of clean, coarse, dry sand, and a similar coating of sand shall be spread over the pavement, if required by the Engineer, before the acceptance of the pavement. The filler NOTE. The committee recommends expansion joints % inch in width at each curb for streets up to 30 ft. in width ; 1 inch in width for streets between 30 and 50 ft. in width and 1% inches in width for streets over 50 ft. in width. used shall be a straight run residue obtained from the distillation of coal tar and shall comply with the following requirements: 1st. The melting point shall be not lower than 135 F., nor higher than 145 F. 2nd. It shall contain between 22 per cent and 37 per cent of free carbon insoluble in hot chloroform and benzol. 3rd. Its specific gravity at 77 F., shall not be less than 1.24 nor more than 1.32. 4th. The specific gravity of the distillate up to 355 C., shall not be less than 1.07 at 38 C, compared with water at 15.5 C. " Thermometers In Kettles. The kettles in which the filler is heated on the street shall be equipped with approved thermometers, and the pitch shall be heated to a temperature of not less than 255 F., nor more than 300 F., and shall be poured when at a temperature between these limits. METHODS OF SAMPLING AND TESTING PRESERVATIVE. Sampling. Continuous Drip Sample. Wherever the oil is being loaded or discharged by means of a pump the following method shall be used : The pipe line thru which the material is being pumped shall be tapped on the discharge side of the pump, preferably in a rising section of the pipe line. The sample shall be taken by means of a ^-inch pipe extending half way to the center of the main pipe, and the inlet of the ^-inch pipe shall be turned to face the flow of the liquid. This pipe shall discharge into a barrel or drum of 50 to 100 gallons capacity, and the plug cock regulated so as to secure a contin- uous uniform stream during the entire pumping of the shipment. The barrel, or preferably the iron drum, should be provided with a small steam coil, sufficient to keep the contents thoroly liquid. The temperature shall not exceed 120 F. The contents of the barrel or drum shall be very thoroly agitated and small samples for testing taken immediately. The amount of the drip sample collected shall be not less than 1 gallon to 1,000 gallons of material handled, ex- cepting in the case of large boat shipments, where a maximum of 100 gallons will suffice. Storage Tank Samples. In sampling from storage it is necessary to secure samples from different levels, and where possible this may be done by means of small outlet cocks at regular intervals from the top to the bottom of the storage tank. In such cases, about 1 gallon of tar or oil shall be drawn from each outlet cock and thoroly mixed and a portion taken for testing. The stream from each cock shall always be allowed to flow for sufficient length of time to empty the outlet pipe and nipple before commencing to collect the sample. When tanks have no outlet cocks a vessel having a string attached to the cork may be lowered to measured depth representing a number of the different levels iii the tank and the cork removed when the vessel has reached the proper level. These samples shall be combined for an average as above. STANDARD DISTILLATION TEST CREOSOTE OIL TESTING. Distillation Test. Apparatus for Distillation Test. (a) Retorts: This shall -be a tubulated Jena glass retort of the usual form with a capacity of 250 to 290 c.c. The capacity shall be measured by placing the retort with the bottom of the bulb and the end of the off-take in the same horizontal plane, and pouring water into the bulb thru the tubulature until it overflows the off-take. The amount remaining in the bulb shall be considered its capacity. (Fig. 1.) (b) Condenser Tube: Any suitable form of glass tubing may be used; a convenient one is shown in Fig. 1. (c) Shield: An asbestos shield as shown in Fig. 2, shall be used to protect the retort from air currents and to prevent radiation. This may be covered with galvanized iron, as such an arrangement is more convenient and more permanent. (d) Receivers: Erlenmeyer flanks of 50 to 100 c.c. capacity are most convenient form. (e) Thermometers: The thermometer shall be of glass, well annealed, and shall undergo no serious change at the zero point when heated up to 400 C. The space above the mercury column shall be filled w r ith gas, either carbon dioxide or nitrogen, and the thermometer shall have an expansion chamber at the top. The scale shall read from to 400 C., in graduations of 1 C., which shall be etched on the stem. The tip of the thermometer shall carry a ring for the purpose of attaching tags. The thermometer shall have the following di- mensions : Total length, 375 mm.; tolerance, 10 mm. Bulb length, 14 mm.; tolerance 1 mm. Distance from zero mark to bottom of bulb, 30 mm. ; tolerance, 4 mm. Scale length from zero mark to 400C., 295 mm. ; tolerance, 5 mm. Diameter of stem, 7 mm. ; tolerance, 1 mm. Diameter of bulb, 6 mm. ; tolerance, 1 mm. When standardized the accuracy of such standardization should be as follows: Up to 200C., to the nearest 0.5C. 200 to 300C., to the nearest 1.0C. 300 to 360 C to the nearest 1.5C. Assembling for Distillation Test. The retort shall be supported on a tripod or rings over tw r o sheets of 20-mesh gauze, 6 inches square. It shall be connected 9 to the condenser tube by a tight cork joint. The thermometer shall be inserted thru a cork in the tubulature with the bottom of the bulb J^ inch from the surface of the oil in the retort. The exact location of the thermometer bulb shall be determined by placing a central rule graduated in divisions not exceeding 1/16 inch back of the retort when the latter is in position for the test, and sighting the level of the liquid and the point for the bottom of the thermometer bulb. The distance from the bulb of the ther- mometer to the outlet end of the condenser tube shall be not more than 24 nor less than 20 inches. The burner should be protected from draughts by a suitable shield or chimney. (Fig. 1.) Distillation Test. Exactly 100 g. of oil shall be weighed into the retort, the appar- atus assembled and heat applied. The distillation shall be con- ducted at the rate of at least one drop and not more than two drops per second, and the distillate collected in weighed receivers. The condenser tube shall be warmed whenever necessary to prevent- ac- cumulation of solid distillates. Fractions shall be collected at the following points: Up to 210 C. ; up to ,235 C. ; 235 to 315 C. ; 315 to 355 C. The receivers shall be changed as the mercury passes the dividing temperature for each fraction. The last receiver shall be removed at 355 C., and drainage from the condenser, etc., shall not be considered as part of the fraction. For weighing the receivers and fractions, a balance accurance to at least 0.05 g. shall be used. During the progress of the distillation the thermometer shall remain in its original position. No correction shall be made for the emergent stem of the thermometer. When any measurable amount of water is present in the distillate it shall be separated as nearly as possible and reported separately, all results being calculated on a basis of dry oil. When more than 2 per cent of water is present, water-free oil shall be obtained by separately distilling a larger quantity of oil, returning to the oil any oil carried over with the water, and using dried oil for the final distillation. A copper tar still is a convenient means of obtaining water-free oil. Specific Gravity Test. Apparatus for Specific Gravity Test. (a) Hydrometer: The hydrometer shall be of the form and dimensions shown in Fig. 3. 10 (b) Cylinder: The cylinder shall be of the form and dimensions shown in Fig. 4. -* > MM HYDROMETER FIG. CYLINDER FIG. -4. Specific Gravity Test. A standardized hydrometer (Fig. 3) shall be used. A set of two ranges, 1.00 to 1.08 and 1.07 to 1.15 will suffice. The reading should preferably be taken at 38 C. (100 F.), because at this tempera- ture almost all oils are completely fluid. Before taking the specific gravity the oil in the cylinder should be stirred thoroly with a glass rod, and this rod when withdrawn from the liquid should show no solid particles at the instant of withdrawal. Care should be taken that the hydrometer does not touch the sides or bottom of the cylinder when the reading is taken, and that the oil surface is free from froth and bubbles. If the specific gravity is determined at a higher temperature than desired, correction should be made by adding 0.0008 to the reading for each degree Centigrade excess of temperature. The sub-committee on wood block paving specifications for igi6 was instructed to gather data regarding specifications for oil and to present a report by February I, 1916, if possible, to be printed in the proceedings, but the committee was appointed too late to com- plete its work and the proceedings were printed without the report. Invitation was extended by the General Committee to those so desiring to send suggestions to the committee regarding provisions 11 desired in the specifications and the following are printed as being the suggestions received by the secretary up to February I. The three members of the new committee, E. R. Dutton, Chair- man, A. W . Dow and H. Von Schrenk, recommend the specifica- tions printed above. P. C. Reilly recommends the following specifications for improved creosote oil: IMPROVED CREOSOTE OIL. 1. The oil shall be obtained by the distillation of coal tar and shall consist wholly of such distillate from coal tar as will comply with the following requirements: 2. The oil shall have a specific gravity of not less than 1.12 nor more than 1.14 at 38C. 3. When the oil is subjected to distillation the distillates shall be as follows: Distillate to 250C. not over 1 per cent. Distillate to 315C. not over 15 per cent. Distillate to 355 C. not over 40 per cent. 4. The residue above 355 C. shall be of a soft waxy nature at 25 C. When a drop is heated on white filter paper until it is ab- sorbed by the paper, the spot formed, when viewed by transmitted light, shall be of a yellowish amber color. 5. When 25 grams of the oil are placed in an open pressed tin box approximately 2 l /2 inches in diameter and ^4 inch deep and kept at a temperature of 49C. (120F.) it shall not lose more than 5 per cent by evaporation in 72 hours. Tests. The residue above 355 C. shall have a specific gravity of not less than 1.17 at 25C. The residue above 355C. shall have a specific gravity of not less than 1.17 at 25C. The residue above 380 C. shall be of a soft waxy nature at 25 C. The specific gravity of the fraction of the distillate 400 C. to 420C. shall be not less than 1.12 at 38C. 12 Sulphonation : When the following fractions of the distillate, 315C. to 380C. and 380C. to 420C., are subjected to the sul- phonation test, neither of them shall contain more than 2 per cent of unsaponical oil in that particular fraction. And I would suggest that any specification adopted should be so drawn as to exclude the use of coal tar or any other kind of tar from the preservative oil, and that the preservative consist of the highest grade of creosote oil. W ' . H. Fulweiler, Chemist of the United Gas Improvement Co., proposes the following: SPECIFICATIONS FOR -PRESERVING OIL FOR USE IN WOOD BLOCK PAVING TREATMENT. (1) Preservative oil shall be a product of water gas tar and be free from admixture of other crude or unrefined tars. (2) The specific gravity at 38 C., compared with water at the same temperature shall be between 1.11 and 1.14. (3) Material insoluble by hot continuous extraction with benzol or chloroform shall not exceed 2% by weight. (4) Distillation to 210 C., shall not exceed 3% by weight. Distillation to 235 C., shall not exceed 10% by weight. Distillation to 315 C, shall not exceed 40% by weight. Distillation to 355 C., shall not be less than 25%. (5) Specific gravity of the distillate at 38 C., compared to 15.5 between 235 C., and 315 C, should not be less than .96, nor more than 1.00. C. N. Forrest, Chemist of the Barber Asphalt Paving Co., for- wards the following: WOOD PAVING BLOCKS. The representatives of The Barber Asphalt Paving Company have opposed the adoption of the specifications for wood paving blocks which were presented at the annual meetings of the American Society for Municipal Improvements in 1914 and in 1915, because that portion of such specifications which defined the character of 13 the preservative oil excluded materials of equal value, from a service point of view, which are more generally available than the specific oil called for. This company is not a producer or distiller of tar of any kind, but is merely conducting a wood treating plant and purchases its oil or tar employed for saturating blocks and other timber entirely from outside sources. It has treated large quantities of wood blocks with coal tar oil of essentially the same character as that proposed in the specifications, as well as with water gas tar and with creosote and various other combinations which may have been called for. There is ample evidence of the sufficiency of other oils and tars than the one proposed, and in view of the impossibility of including all of them in a single specification without making its requirements too general to be effective, we, therefore, suggest that the require- ments for the preservative be described under two separate heads as follows : Type "A" Coal-Tar oil. Type "B" Water-Gas Tar oil. The preservative proposed for adoption by the committee is described as a coal tar oil, but could be a mixture of coal-tar and water-gas tar products as far as any of the tests mentioned in the specifications are concerned. We do not criticise it as being unsuitable for the purpose, but water-gas tar is equally suitable and has the advantage of being more available and of lower cost to all concerned. We, therefore, propose the following specification for a preservative consisting of water-gas tar as an alternative of the coal tar preservative pro- posed by the committee: The preservative shall be refined water-gas tar, and shall comply with the following requirements: 1. The specific gravity shall be not less than 1.12 nor more than 1.14 at 38 C., referred to water at the same tem- perature. 2. Not more than 2.0% shall be insoluble by hot extraction with benzol and chloroform. 3. On distillation which shall be made as hereinafter de- scribed, the distillate, based upon water-free oil, shall be within the following limits: 14 Up to.210C., not more than 5.0% Up to 235 C., not more than 15.0% Up to 315C., not more than 40.0% Up to 355C, not less than 25.0% 4. The specific gravity of the total distillate below 355C., shall not be less than 1.00 at 38C., referred to water at the same temperature. 5. The oil shall not contain more than 2.0% water and due allowance shall be made for all water and insoluble for- eign matter it may contain by injecting a corresponding additional quantity into the blocks. The Barber Asphalt Paving Company has treated millions of wood blocks with Water-Gas Tar of the above character and such blocks have been in practical service as long as coal tar blocks, as both kinds were introduced about ten years ago. In 1908 about 22,000 square yards of water-gas tar blocks were laid in Boston, Pittsburg, Harrisburg, New London, Zanesville, and Havana, Cuba, and in subsequent years have been laid in quantity in a great variety of locations without a single failure. There is, therefore, indisputable evidence of the suitable character of the pre- servative described in our proposed specification for water-gas tar, and such a specification will not admit a tar of unsuitable character for the purpose, nor one which has been mixed with petroleum distillates or residues of any kind. The above recommendations are made in response to a request of the Committee on Specifications at the Dayton meeting for such recommendations before February 1st, 1916. J. W . Howard, Consulting Engineer on roads and pavements, New York City, recommends the following specification: The preservative used must be a distillate creosote oil of above 1.03 sp. grav. at 38 C. (100 F.), containing less than 1% of matter insoluble in benzol by hot extraction. It shall be waterproof, antiseptic, containing at least 10% of crystallizable naphthalene, and at least 15% of the stable anthracene oil. When distilled as described in Bulletin No. 65, American Railway Engineering and Maintenance-of-Way Association, the total distillate on basis of 15 water-free oil up to 150 C. (302 F.), shall not exceed 1%; the total up to 200 C. (392 F.), shall not exceed 5%. The distilla- tion shall be continued to 315 C. (600 F.), and the residue then remaining, when cooled to 25 C. (77 F.), shall be soft and easily indented with the finger. The creosote oil used shall be a distillate made from coal-tar or a combination of distillates from coal-tar and water-gas tar, provided the oil produced meets all the above tests of qualities needed for thoroly preserving wood. 14 DAY USE RN TO DESK FROM WHICH BORROWED LOAN DEPT ubject to immediate recall. JAN 8 3 1959 LD 21A-50m-9,'58 (6889slO)476B .General Library University of Calif or Berkeley UNIVERSITY OF CALIFORNIA LIBRARY