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 TA 
 
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 B32 
 
RESOLUTIONS 
 
 
 OF THE 
 
 ions held at Mil, Dresden, Berlin, and Vienna, 
 
 FOR THE 
 
 PURPOSE OF ADOPTING UNIFORM METHODS FOR TESTING 
 
 CONSTRUCTION MATERIALS WITH REGARD TO 
 
 THEIR MECHANICAL PROPERTIES, 
 
 BY 
 
 J, BAUSCHINGEE, 
 
 PROFESSOR IN TH E TECHNICAL H IGH SCHOOL, MUNICH. 
 
 TRANSLATED BY 
 
 O. M. CARTER, 
 
 CAPTAIN, COUPS OK ENGINEERS, U. S. A., 
 AND 
 
 K. A. GIESELER, 
 
 UNITED STATES ASSISTANT ENGINEER. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 
 1896. 
 
RESOLUTIONS 
 
 OF THE 
 
 Cooveofastidtl at Municti, Dresden, Berlin, and Vienna, 
 
 FOR THE 
 
 PURPOSE OF ADOPTING UNIFORM METHODS FOR TESTING 
 
 CONSTRUCTION MATERIALS WITH REGARD TO 
 
 THEIR MECHANICAL PROPERTIES, 
 
 BY 
 
 J, BAUSOHINGEE, 
 
 PROFESSOR IN THE TECHNICAL HIGH SCHOOL, MUNICH. 
 
 TRANSLATED BY 
 
 O. M. CARTER, 
 
 CAPTAIN, CORPS OF ENGINEERS, U. S. A., 
 AND 
 
 E. A. GIESEUER, 
 
 UNITED STATES ASSISTANT ENGINEER. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 189G. 
 
WAK DEPARTMENT 
 , . . Document No. J.. , 
 OJfiwbf the C-kief ef Eh^neers. 
 
UNITED STATES ENGINEER OFFICE, 
 
 Savannah, Ga., January 13, 1896. 
 
 GENERAL: I have the honor to transmit herewith a translation from 
 the German of the Resolutions of the Conventions held at Munich, 
 Dresden, Berlin, and Vienna, for the Purpose of Adopting Uniform 
 Methods for Testing Construction Materials with Regard to their 
 Mechanical Properties. The resolutions are of value, and, I think, 
 should be printed for distribution to the officers of the Corps of 
 Engineers. 
 
 Very respectfully, your obedient servant, 
 
 O. M. CARTER, 
 Captain, Corps of Engineers. 
 Brig. Gen. WM. P. CRAIGHILL, 
 
 Chief of Engineers, U. S. A. 
 
 [First indorsement.] 
 
 OFFICE CHIEF OF ENGINEERS, 
 
 U. S. ARMY, 
 
 January 18, 1896. 
 
 Respectfully submitted to the Secretary of War, with the recom- 
 mendation that the work be printed at the Government Printing Office 
 for the use of the Corps of Engineers, and that 300 copies be obtained 
 on the usual requisition. 
 
 W. P. CRAIGHILL, 
 Brig. Gen., Chief of Engineers. 
 
 [Second indorsement.] 
 
 WAR DEPARTMENT, 
 
 January 21, 1896. 
 
 Approved as recommended by the Chief of Engineers. 
 By order of the Secretary of War : 
 
 JOHN TWEEDALE, 
 
 Chief Cleric. 
 
 M46822 
 
CONTENTS. 
 
 Page- 
 Introduction _ 7 
 
 I. General provisions 11 
 
 1. Requirements of testing machines 11 
 
 2. Arrangements for mounting test pieces 11 
 
 3. Uniform testing machine 11 
 
 4. Data concerning machines and methods, to bo given when commu- 
 
 nicating results 11 
 
 5. Data in regard to test [pieces, to be given when communicating 
 
 results , 11,12 
 
 6. Limits of exactitude .., 12 
 
 7. Influence of time on tests of strength 12 
 
 8. Materials should be tested for the class of strains occurring during 
 
 actual use 12 
 
 9. Impact tests for material subjected to shock when in use 13 
 
 10. Standard impact machine 13 
 
 II. Tests of wrought iron and steel 16 
 
 A. Rails, Nos. 1-6 16 
 
 B. Axles, Nos. 1-3 17 
 
 C. Tires, Nos. 1-3 17 
 
 D. Multiple or piece tests, Nos. 1-3 17 
 
 E. Wrought iron for bridges, Nos. 1-3 18 
 
 F. Low or mild steel for bridges, Nos. 1-2 18 
 
 G. Wrought iron for boiler work, Nos. 1-3 18 
 
 II. Low or mild steel for boiler work, Nos. 1-5 18 
 
 The place at which, and the manner in which, test pieces should 
 
 be cut out of boiler plates 19 
 
 I. Wire, Nos. 1-3 20 
 
 K. Wire rope, Nos. 1-2 20 
 
 L. Measurements to be made in tension tests, Nos. 1-5 21 
 
 M. Form of test pieces for tension tests, Nos. 1-7 21 
 
 N. Bending tests 23 
 
 III. Tests of cast iron, Nos. 1-7 24 
 
 IV. Tests of copper, bronze, and other metals 25 
 
 V. Tests of wood, Nos. 1-7 26 
 
 VI. Tests of shipbuilding materials, Nos. 1-2 28 
 
 VII. Tests o f stone 28 
 
 A. Stone in general ; resistance to boring or quarrying, Nos. 1-5 28 
 
 B. Building stone 30 
 
 a. Natural building stone, Nos. 1-11 30 
 
 /?. Artificial build ing stone 32 
 
 aa. Bricks, Nos. 1-7 32 
 
 j8/3. Roofing tiles, Nos. 1-8 34 
 
 C. Paving and ballast material, natural and artificial, Nos. 1-11 35 
 
 D. Tests of preservatives for natural and artificial stone 36 
 
 5 
 
Page. 
 
 VIII. Tests of hydraulic binding media 37 
 
 A. General remarks, Nos. 1-2 37 
 
 B. Nomenclature, Nos. 1-6 38 
 
 C. Tests 38 
 
 1. Weight 38 
 
 2. Fineness of grain 38 
 
 3. Conditions of setting 39 
 
 4. Constancy of volume 40 
 
 5. Tests of strength 42 
 
 6. Adhesive strength 44 
 
 7. Density 44 
 
 8. Action of sea water on hydraulic binding media 44 
 
 New problems 44 
 
INTEODUOTIOISr. 
 
 * * 
 I V 
 
 It is universally acknowledged at the present day that tests of mate- 
 rials of construction with regard to their mechanical properties are com- 
 parable with one another and give practical results only when they are 
 made according to uniform methods. The recognition of the necessity 
 for such uniformity brought about as early as 1876 the adoption of 
 u Standard rules for furnishing and testing Portland cement" by the 
 Association of German Portland Cement Manufacturers, also the 
 "Drafts of specifications for furnishing axles, tires, and rails of iron 
 and steel" which were recommended in 1879 by the Association of 
 German Eailway Administrations for adoption by its members. 1 
 
 Those first attempts at unifying the methods of testing emanated, 
 however, from too narrow sources, from manufacturers only on the one 
 hand and from consumers only on the other, and their suggestions 
 were naturally governed by their respective interests ; at least this was 
 asserted to be the case. Each of those agreements, moreover, had the 
 inconvenience of relating to only a single group of materials; further- 
 more, they were not confined to methods of testing, but specified con- 
 ditions to which materials should conform when tested according to 
 prescribed methods. 
 
 The convention held in the autumn of 1884 at Munich, composed of 
 representatives of all the technical professions, with the aim of unifying 
 the methods of testing the principal materials of construction, neglect- 
 ing entirely any classification of those materials, was consequently jus- 
 tified. That convention succeeded in agreeing upon quite a series of 
 important questions, while a certain number of others were referred to 
 a permanent committee, which thoroughly discussed them, first in writ- 
 ing and then orally, at its two sessions held in Munich on the 21st and 
 22d of September, 1885, 2 and which finally submitted a report upon the 
 results of its labors to a second convention, held in Dresden on the 20th 
 and 21st of September, 1886. 
 
 The latter convention accepted almost all of the propositions which 
 
 ! The properties of iron and steel. Seventh supplementary volume to "Organ fur 
 die Fortschritte des Eisenbahnwesens." Wiesbaden, 1880. 
 
 2 A detailed report 011 the discussions of the Munich convention and the perma- 
 nent committee appointed by it is contained in No. XIV of "Mittheilungen aus 
 dem mechanisch-technischen Laboratorium der technischen Hochschule/' Muenchen. 
 (Munich, Th. Ackcrmann.) 
 
 7 
 
8 
 
 were submitted to it, but charged a second permanent committee with 
 the study of a series of questions which had not yet been taken hold of or 
 agreed upon, with instructions to render a report to a third convention, 
 which was to meet on the 19th and 20th of September, 1890, in Berlin. 
 At that convention resolutions were adopted with regard to a certain 
 -number of propositions, while others, together with certain new ques- 
 tions, wore r&ferrexlto a third permanent committee, charged with pre- 
 ;.. n$ing.a.:?epprt>to a fourth convention, which was to be held at Vienna 
 oil th'e24th ab4'25th of May, 1893. At that convention an agreeme.it 
 was reached again 011 only a portion of the proposed resolutions, and 
 the others were referred, with a great number of new questions, to a 
 fourth permanent committee, the executive of which was at the same 
 time charged with the preparation of a memoir containing all of the 
 resolutions adopted up to that date, as well as all of the questions upon 
 which no agreement had been reached, in the same way as had been 
 done for the first two conventions in a pamphlet entitled "Resolutions 
 of the Conventions held at Munich and Dresden," etc. 
 
 The hope expressed in that pamphlet that its publication might aid in 
 sustaining tbe eiforts already put forth, and at the same time induce those 
 who, up to that date, had not interested themselves in such questions 
 to participate in the future, has been fulfilled in a very gratifying way. 
 Not only has there been an increase in the number of delegates from 
 countries already represented (Germany, Austria-Hungary, Switzer- 
 land, Russia), but delegates have come from other countries (France, 
 America, Norway, Holland, Italy, Spain), so that the conventions have 
 assumed a truly international character. With the aim of developing 
 this movement still more it should be remembered that each conference 
 is a reunion at which all members can exchange freely their opinions 
 as to the best methods to be employed for testing as to its mechanical 
 properties a certain material intended for a certain purpose. Votes 
 and resolutions have no other aim than to bring out the methods of 
 testing which the majority of the members prefer. In conformity with 
 the first resolution of the first conference, " deliberations are to be 
 free and resolutions not obligatory." There is nothing to prevent a 
 question which has been acted upon in a preceding conference from 
 being taken up again, discussed, and submitted to a new vote. The 
 methods of testing can not remain unchangeable; they must progress 
 with our knowledge of the properties of the materials that we employ, 
 with the improvements brought about in the production of those 
 materials, with the employment of new materials, etc. It is then neces- 
 sary that those who are occupied with tests of construction materials 
 whether from a scientific point of view or because they are making or 
 using such materials should meet from time to time to exchange 
 opinions, to mutually instruct one another, and from such deliberations 
 to agree upon methods of testing that they judge to be the best, or at 
 least that the majority among them find to be the most suitable for the 
 time being. 
 
Present methods of communication Lave so nearly eliminated the 
 dividing- line between all civilized and manufacturing countries that 
 the unification of methods of testing will have little value if it is limited 
 to a few countries. The recognition of the necessity for international 
 agreement has led the conferences, which were participated in at the 
 beginning only by Germany and some immediately neighboring coun- 
 tries, to become more and more international in character. 
 
 By a decree of the 9th of November, 1891, the President of the French 
 Republic created a u Commission des methodes d'essai des materiaux 
 de construction," whose object, as its name indicates, is the same as 
 that of the conventions of Munich, Dresden, Berlin, and Vienna, and 
 their permanent committees. Such national institutions have cer- 
 tainly two great advantages; they have, at least at home, greater 
 authority and it is easier for them than for private societies to procure 
 funds for necessary experimental research. It is evident that they lack 
 an international character, but that could be obtained by a suitable 
 agreement between the different national commissions; but then the 
 advantages before mentioned resulting from the private character of 
 those conferences would be lost. On the other hand, the advantages 
 resulting from governmental support could very well be combined with 
 those inherent in conventions such as have been held up to the present, 
 if the permanent committees, working in the interval between the ses- 
 sions of the conventions, were composed as well of representatives of 
 private industry as of technical government delegates and delegates 
 from technical associations and societies. 
 
 To effect those aims the president of the fourth permanent committee 
 elected by the convention at Vienna was instructed to make every 
 effort in order that the greatest possible number of technical associa 
 tions and societies should send delegates who would thus participate 
 in the labors of the committee. 
 
 In the following compendium the resolutions passed so far are printed in ordinary 
 ronian type; a short statement of the reasons for their adoption is printed in small 
 roman type, and questions still open to discussion are printed in italics. 
 
UNIFORM METHODS FOR TESTING CONSTRUCTION 
 MATERIALS WITH REGARD TO THEIR MECHANICAL 
 PROPERTIES. 
 
 I. GENERAL PROVISIONS. 
 
 1. All machines for testing materials should be arranged in such a 
 way that their adjustment can be verified with ease and certainty. 
 
 Their construction must be such that with proper handling sudden, 
 shock-like action of the load is excluded as much as possible. Machines 
 acting by hydraulic pressure, as well as those acting by means of a 
 screw, conform to this condition. For practical purposes no separate 
 attachment making the machine self-acting is required. 
 
 2. The arrangement for securing the test piece in the machine must 
 be such as to allow as much as possible uniform distribution of strain 
 in the cross section. 
 
 To obtain this the following is required: 
 
 (a) For pressure tests 
 
 (a) One of the two pressure plates must move easily and freely in 
 all directions. 
 
 (I) The pressure surfaces of the test pieces must be as nearly plane 
 and parallel as possible, and with this object in view should be planed 
 or turned whenever the material admits of either of those operations. 
 
 (/?) For tensile tests 
 
 There shall be freedom and ease of movement for adjustment of posi- 
 tion at commencement of tension. Experience shows that this con- 
 dition is obtained: In the case of round bars, by means of spherical 
 bearings; in the case of flat bars, by means of slot and bolt (one slot 
 and one bolt on each side), or milled ends and corresponding wedges. 
 
 Serrated wedges that cut into the test pieces should never be used. 
 
 3. It is impossible to recommend for practical use a uniform appara- 
 tus for tests of strength; it may be stated, however, that a number of 
 well-known machines are more or less well adapted for their particular 
 purposes. 
 
 4. In communicating results of tests there should be given such data 
 in regard to the machines and methods employed as are required to 
 enable one to judge of the value of the tests. 
 
 5. Whenever possible, results of tests should be accompanied by 
 information as to whence the test piece came, by a microscopical or 
 a chemical examination, or both, by data relating to the manner of 
 its manufacture, and other known physical, chemical, or technical 
 properties. 
 
 11 
 
12 
 
 In the case of tests intended mainly for practical purposes it will rarely be prac- 
 ticable to include sucb complementary information ; still, for the sake of comprehen- 
 sive results, its acquisition is always desirable, and it should never be neglected in 
 the case of scientific investigations. 
 
 6. Regarding the required degree of exactitude of testing machines 
 and of the results of tests of materials, the following should be 
 observed : 
 
 (a) To economize time, the limit of exactitude in measuring changes 
 of force and of form should not be extended beyond the limit of un- 
 avoidable errors and of imperfection of materials. 
 
 (b) In scientific experiments it is obvious that the highest possible 
 degree of precision should be sought. 
 
 (c) In publishing results of tests the degree of precision attained 
 should be given, or data should be furnished from which an opinion in 
 regard to it can be formed. 
 
 Present experience justifies the following proposition: 
 
 (d) In the case of metals when test bars of standard dimensions are 
 used (such as are described below under II M and under IV) the fol- 
 lowing degrees of exactitude are sufficient: Strains, at the limit of 
 rupture, should be measured to tenths of a kilogram per square 
 millimeter; elongation at rupture should be measured to tenths of 1 
 per cent; reduction of cross-sectional area should be measured to the 
 nearest full per cent. 
 
 In figures given according to this schedule the last digit is generally 
 unreliable; consequently it is useless to add any further decimals. In 
 order to conform as far as practicable to the above degrees of exacti- 
 tude, length and cross-sectional dimensions should be determined to 
 tenths of millimeters. 
 
 7. According to Fischer and Hartig, time exercises an undoubted 
 influence on tests ot strength; still other experiments made since then 
 have demonstrated that there is not at present any sufficient reason to 
 warrant a demand for any fixed velocity of stretching in testing the 
 principal materials of construction, viz, iron in all its forms, copper and 
 bronze (see Bauschinger's experiments in No. 20 of his u Mittheiluugen, 
 etc."). 
 
 8. Materials should be tested for that class of strains to which they 
 will be statically subjected in actual use. 
 
 The quality of a material per se is the sum of its mechanical properties. So long as 
 we are ignorant of the relations existing between these, and, therefore, are unable 
 to judge from one or more of them as to the nature of the rest which we are far 
 from being able to do at present so long will it remain impossible to foretell the 
 behavior of a material under different conditions of strain, merely from a determi- 
 nation of one or several of its properties, and so long will it therefore remain 
 necessary to test materials in regard to the mechanical properties required in actual 
 use. 1 
 
 J For an ample demonstration of this resolution, see "Mittheilungen," etc., No. 14, 
 pp. 156-160. 
 
13 
 
 9. All materials which will be submitted to shocks when in actual 
 use should be tested by impact, in order to study fully their qualities. 
 
 10. Tests by impact should be made by a standard impact testing- 
 machine, to be constructed as follows: 
 
 (a) It is not considered necessary to prescribe the complete construc- 
 tion of a standard impact-testing machine, but merely to give accurate 
 instructions in regard to all of those parts which can possibly exercise 
 any influence on the results of tests. It is recommended that the 
 frame of the machine should be made of iron. 
 
 It was thought necessary to take into consideration existing apparatus, the essen- 
 tial parts of most of which conform to the following requirements : 
 
 (b) Every standard impact testing machine should be officially 
 gauged. 
 
 It is not impossible that a machine constructed with the greatest care may give 
 false results on account of unforeseen influences. 
 
 (c) Iii accordance with the requirements of German railway admin- 
 istrations, and considering that impact testing machines should be 
 housed, the normal weight of hammer should be 1,000 kilograms, 500 
 kilograms being allowed in exceptional cases. 
 
 (d) The hammer may be made of cast iron, of cast or of wrought steel; 
 its form should be such as to have the center of gravity as low down as 
 possible. The face of the hammer should be made of wrought steel and 
 secured by means of dovetail and wedges, ex- 
 actly centrally to its vertical axis. The fact 
 
 that this requirement has been complied with 
 should be indicated by special marks. The 
 center of gravity of the hammer must coincide 
 with the center line of the leads. This line 
 should be indicated by special marks on the 
 anvil or the anvil block. '*" Fia 
 
 (e) The guided length of hammer should 
 
 be more than twice the clear width between guides. The leads should 
 be made of metal, for instance of railroad iron, the hammer being allowed 
 but little play between them. Lubrication of the leads with plumbago 
 is recommended. 
 
 (/) Shock machines must be provided with an apparatus allowing 
 the hammer to be set securely at the desired height. The detaching 
 apparatus ought not to produce any wedging of the hammer in the 
 guides; therefore the part carrying the detaching apparatus should be 
 well guided. The point of suspension should be on the same vertical 
 as the center of gravity of the hammer, and there should be placed 
 between the detaching device and the hammer a flexible piece of short 
 length, for example a chain or a cord. The detaching device officially 
 prescribed in Eussia and represented by the sketch herewith (fig. 1) is 
 to be recommended. 
 
 (g) With a constant height of fall an automatic detaching device is 
 recommended. 
 
14 
 
 (7i) The bearings for the test pieces should be attached rigidly to the 
 anvil block for instance, by the aid of wedges. 
 
 The bearing blocks should be made to form as nearly as possible one single mass 
 with the anvil block. 
 
 (i) The weight of the anvil block should be at least equal to ten times 
 that of the hammer. 
 
 Since comparative tests which have been made with a ballistic apparatus and an 
 ordinary hammer have proved that with an anvil mass four times heavier than the 
 hammer the results are sufficiently concordant (see Kick on the Law of Proportional 
 Resistances), one may be sure that with a total anvil mass ten times heavier than 
 the striking hammer the results will always be comparable with one another. 
 
 (k) The foundations should not be elastic; they should be built of 
 solid masonry and have dimensions determined by the nature of the 
 ground. 
 
 (?) The striking surface of the hammer should always be plane; there- 
 fore, in testing rails, axles, and tires use should be made of interposed 
 pieces dressed to the required shape and having plane upper surfaces. 
 The interposed pieces should be as light as possible. 
 
 The same hammer with plane striking surface is recommended in all cases, for the 
 sake of simplicity of preparation as well as in consideration of the correction of 
 hammer weight according to o and p. 
 
 (m) The results of previous experiments are not conclusive enough 
 to determine the form of the supports and of the pieces destined to 
 receive the shock or blow. It is recommended, however, that there 
 should be given in reports of tests, or when exhibiting tested samples, 
 exact information regarding the forms employed. 
 
 (n) More confidence can be placed in machines whose height of fall 
 is not greater than 6 meters than in those with a greater height of fall. 
 It is recommended, therefore, that that height should not be exceeded 
 in new constructions. Where a stronger blow is desired, a hammer 
 weighing 1,000 kilograms should be employed. 
 
 Machines with a height of fall of 6 meters can bo housed easier and can be con- 
 structed with more reliability than higher ones. Their parts are also less susceptible 
 of being disarranged. 
 
 (o) The impact work produced by the hammer is the product of its 
 effective weight by its height of fall. Its total weight should be regu- 
 lated so that its effective weight amounts to some round figure for 
 instance, 500 kilograms. 
 
 The results are comparable with one another only when the loss of living force due 
 to friction is eliminated. 
 
 (p] To determine the effective weight of the hammer, the following 
 methods are employed : 
 
 (a) A spring balance is placed between the hammer and its lifting 
 rope, and the effective weight is read during slow descent; there is 
 thus obtained the weight of the hammer less the friction. The upward 
 movement furnishes the same weight augmented by the friction. 
 
15 
 
 (ft) The weight of the hammer can be deduced also from the effect 
 produced, with a given height of fall, on a centrally mounted standard 
 cylinder, made of best stay-bolt copper, of a shape and weight still to 
 be determined. 
 
 (q) These standard cylinders should also be used to compare impact 
 machines with one another and to gauge them. 
 
 The Mechanical Testing Institute at Charlottenburg has already made such com- 
 parative tests, and no doubt will willingly take charge of others if it is requested so 
 to do. 
 
 (r) Impact machines which have a work due to friction greater than 2 
 per cent of their useful work should be rejected. 
 
 In order to have conclusive shock tests there should be employed only faultless 
 machines ; those that are badly constructed or badly kept up must not be used. 
 
 (*) The standard impact testing machine is destined principally for 
 the testing of whole pieces, such as rails, axles, tires, springs, etc. 
 
 The testing of pieces specially prepared for shock trials is certainly of great inter- 
 est, but principally of a scientific one only, and therefore it is not considered, neces- 
 sary at present to give rules for the construction of a special small impact machine 
 and for the methods of conducting such tests. 
 
 (t) The vertical position of the guides and the proper location of the 
 hammer between the guides should be rigorously controlled. The ver- 
 tical projection of the center of gravity of the hammer on the anvil's 
 surface should be marked on the anvil, and whether the test piece is 
 properly placed in the vertical of the center of gravity of the hammer, 
 and whether its placing may not cause pinching or torsional deforma- 
 tion should be verified previous to every blow. 
 
 (u) The work done by a hammer within very wide limits depending 
 only on the product of its fall by its effective weight, and not on one of 
 those factors individually, it is recommended that the metric ton should 
 be taken as the unit and that such an arrangement should be made as 
 will insure the product always being a multiple of 500. Instead of 
 graduating the divisions on the scale to meters they will be divided 
 into metric half tons. 
 
 (v) It is recommended that sliding scales should be used in order that 
 the zero of the graduation may always be set according to the height of 
 the test piece. 
 
 (w) The determination within a millimeter of the deflection by impact 
 of test pieces resting on supports from 1 to 1 meters apart, is so far 
 considered sufficiently exact. 
 
 (x) To facilitate comparison of the results, it is recommended that 
 all particulars of the tests should be given for example, the order in 
 which the blows of the hammer were given, whether there was any 
 interruption of the test, and whether the test pieces were reversed or 
 not, also all the phenomena observed during the test. 
 
 (y) The permanent commission should study the new propositions con- 
 cerning the construction of impact machines and talce especial pains to col- 
 
16 
 
 lect the results of all experiments made in regard to the conduct of impact 
 tests, in order to utilize them for devising a uniform method of testing. 
 
 A drawing of an impact machine designed by Engineer Schmitz of 
 Vienna and fulfilling all of the above conditions has been referred to 
 the committee for its further study. 
 
 II. TESTS OF WROUGHT IRON 1 AND STEEL. 
 A. RAILS. 
 
 1. Rails, for reasons of safety and in accordance with the resolution 
 under Heading I, No. 9, should be tested by the shock method by means 
 of suitable technical devices. (Standard impact machines; see I, 
 No. 10.) 
 
 2. If further information concerning the naiure of the metal is desired 
 tension tests will be made. 
 
 3. Finally, rails should be subjected to transverse tests by a static 
 load, and in two ways; up to permanent set in order to determine the 
 elasticity, and by means of heavy loads beyond the limit of elasticity 
 in order to determine the greatest permanent deflection. 
 
 Members of the Munich convention have nearly unanimously recognized that for 
 rails tension tests alone are not conclusive enough. Professor Tetmajer has given 
 plain evidence of this in mentioning contradictions which have been found on Fin- 
 nish, Swiss, and French railways between the results of tension tests and the results 
 obtained in service. Those contradictions arise from the fact that in the first place 
 rails in actual service are strained by shock, and in the second place that the tension 
 test relates only to a small part of the cross section ; there is, therefore, reason for 
 attaching more importance to shock and transverse tests, provided they are made 
 with well-designed apparatus, the shock tests especially being made by means of 
 standard impact testing machines; but as those tests do not furnish as many indica- 
 tions concerning the nature of the metal as do tension tests, especially when the 
 latter are supplemented by chemical analysis, there is reason to maintain that ten- 
 sion tests should be employed as long as their deductions may be useful, which will 
 probably be the case for a long time. 
 
 4. Tension tests should be made on pieces rectangular in section and 
 taken from the exterior fibers of the rail. 
 
 One cause of doubt regarding the results of tension tests arises from the fact that 
 up to the present the round bars used for the tests were taken from the center of 
 the head of the rail so that the libers subjected to the greatest strains, that is, the 
 exterior ones the ones located at the wearing surface and at the seat of the rail 
 were not submitted to the test. But in the case of cast steel, these are the very 
 parts containing the dangerous blowholes due to silica, which always gather near 
 the surface of the ingots. It should be remarked, on the other hand, that in the 
 interior of ingots of pure manganese steel there is a /one of blowholes which may 
 have an unfavorable influence on the tension test, but not on the rail itself, and 
 which may therefore give rise to erroneous conclusions. * 
 
 1 The term " wrought iron " is here used as distinguished from " cast iron," and is 
 intended to comprise "'wrought iron" proper and "mild steel." 
 
 2 For details see " Mittheilungen der Eidgenossicheii Festigkeitsaustalt," No. 3, 
 pp. 42-53. 
 
17 
 
 5. The search for methods of test suitable for determining the wear 
 on rails and tires resolves itself into a search for methods suitable for 
 determining the resistance to wear. At all events it is certain 
 
 (a) That the resistance to wear can not be determined by an experi- 
 mental process. 
 
 (6) That the test of the resistance to wear should be made under con- 
 ditions approaching as closely as possible those to which the metal will 
 be subjected during service. 
 
 On account of its difficulty this question is for the present set aside. 
 
 6. The investigation relative to the influence of different kinds of 
 tires on the wear of rails should be considered as a special study per- 
 taining to the administration of railroads. 
 
 B. AXLES. 
 
 1. The ends, as well as the bodies, of axles should be subjected to 
 shock tests. 
 
 2. When further information regarding the nature of a material is 
 desired tension tests should also be made. 
 
 3. Axles need not be subjected to transverse tests. 
 
 C. TIKES. 
 
 1. Tires should be submitted to shock tests in the same manner as 
 axles and rails. 
 
 2. Tension tests should be made if, as above, further information in 
 regard to the nature of the material is desired. 
 
 3. The hammering test is not necessary. 
 
 D. MULTIPLE OR PIECE TESTS. 
 
 1. There should be collected as much information as possible for the 
 purpose of devising standard rules for multiple or piece tests (test of each 
 piece in a lot). 
 
 2. In deciding upon standard rules for impact testing machines and 
 machines for tests of strength there should be kept in view the possibility 
 of making multiple or piece tests. 
 
 3. Not only axles should be thought of in this connection, but all con- 
 struction material of steel and iron. 
 
 The multiple or piece test, whicli consists in testing rapidly by a single shock, for 
 example, each piece of a lot, in such a way as not to injure it, certainly offers more 
 of a guaranty than that which consists in testing so many per cent of the pieces of 
 a lot. It has been adopted for a long time for springs, chains, pipes, steam pipes, 
 boiler tubes, etc. It has given good results in Austria, where it has been used in a 
 number of cases for axles. It must, however, be recognized that that method otters 
 great difficulties for the buyer as well as for the seller, but those difficulties can be 
 overcome by the study and adoption in practice of a well-suited mode of test. The 
 only experience available so far in regard to multiple testa has been gathered at 
 Witkowitz, with axles only, and has lately led to abandoning this method of test. 
 It is desired, however, that more experience should be gathered. 
 10389 2 
 
18 
 
 E. WROUGHT IKON FOR BRIDGES. 
 
 1. Wrought iron entering into the construction of bridges should be 
 submitted to tension tests, and also 
 
 2. To bending tests, both hot and cold, over a mandril 25 mm. in 
 diameter, by means of a slowly working mechanical contrivance. 
 
 The exact conditions that this contrivance should fulfill are given 
 hereafter under N. 
 
 3. Those two tests being sufficient, there is no necessity of making 
 tests for flattening and rupture. 
 
 F. Low OR MILD STEEL FOR BRIDGES. 
 
 1. Low steel entering into the construction of bridges should be 
 submitted, like wrought iron, to tension tests. 
 
 2. It should also be submitted to bending tests, both hot and cold, 
 over a mandril 25 mm. in diameter, by means of a slowly working 
 mechanical contrivance. 
 
 G. WROUGHT IRON FOR BOILER WORK. 
 
 1. The portions of boilers composed of wrought iron should be sub- 
 mitted to the following tests: 
 
 (a) For plates: 
 
 (1) Tension test. 
 
 (2) Bending test. 
 
 (3) Forging and punching test. 
 (&) For angle irons: 
 
 (1) Tension test. 
 
 (2) Bending test. 
 
 (3) Forging and punching test. 
 (c) For rivet iron : 
 
 (1) Tension test. 
 
 (2) Forging and bending test. 
 
 2. The welding test for angle iron is not absolutely necessary, but it 
 is desirable. 
 
 3. Hot shortness (rupture while hot), which would be shown by it, 
 is also demonstrated by the hot bending test. 
 
 H. Low OR MILD STEEL FOR BOILER WORK. 
 
 Wherever bars and plates of mild steel (Bessemer, Martin, or Thomas) 
 take the place of wrought iron in the construction of boilers they 
 should be submitted to the following tests : 
 
 1. Tension tests. 
 
 2. Gold and red-hot bending tests. The edges of test pieces should 
 be chamfered ; if plates are more than 6 mm. thick, the bending should 
 be done around a mandrel 25 mm. in diameter, by means of a slowly 
 working mechanical contrivance, and up to the limit of a given angle. 
 
19 
 
 This test furnishes ail example of how the material will behave when Avorked 
 into a boiler. A mandrel 25 mm. in diameter is handy, and conforms to the direction 
 most commonly followed at present. 
 
 3. Beudiiig tests after tempering. The test pieces, which are cham- 
 feied along their edges, should be heated uniformly throughout their 
 entire length to a cherry red (550 to 650 C.), then quenched in water 
 of about 25 C., and then bent according to the instructions given 
 under 2, above. 
 
 Experience has shown that there should be employed for boilers onry such mild 
 steel as is but little hardened by quenching and readily worked after it. Mild 
 steel, having a resistance of from 38 to 42 kilograms per square millimeter, and 20 
 per cent elongation, generally fulfills this condition, but it is, however, prudent to 
 submit it to the above bending tests after having tempered it. 
 
 4. Forging tests that is to say, flattening out while red hot. The 
 test for punching is useless, because the punching of holes in plates of 
 mild steel should be avoided, on account of the resulting fissures. 
 
 5. It is recommended that those establishments which employ mild 
 steel in practice should make also tests for its welding properties. 
 
 Against the general introduction of the welding test there may be urged above all 
 its difficulty, the dependence of its success upon the skill and experience of the 
 workmen, and finally the fact that, while rnild steel can be welded, riveting is safer. 
 It is true that corrugated and rolled plates of the Fox patent, fire tubes and gas 
 tubes of mild steel, are welded, but all of those pieces are tested individually (multi- 
 ple test). Again, weldable mild steel either can not be tempered at all, or at least 
 not readily tempered, and is less sensitive to temperature, but all of this is deter- 
 mined already by the bending test when tempered. 
 
 Tests of plates of annealed mild steel are unnecessary. The following are the 
 reasons against such tests : On account of the cost, plate iron is not always annealed. 
 Only in the case of small diameters is rolling done Avhilo hot. In hand Hanging the 
 plates are heated only locally. Pitted heads are no longer annealed, because annealing 
 distorts them. The presence of strains in the metal can not be determined by that test. 
 
 During the process of annealing it is not only difficult to determine the tempera- 
 ture, which is of so much importance, but also the time of its action. Measure- 
 ments of temperature would complicate tests A^ery much. Finally, the real issue 
 always is to determine the nature of the material in the condition that it is delivered. 
 
 In favor of tests after annealing, there may he mentioned, firstly, on account of 
 interior strains which exist in plates of mild steel, comparative results can be obtained 
 only when they are annealed ; secondly, the . same material when rolled into plates 
 of different thicknesses gives different results, and, finally, comparative tests made 
 of annealed plates and of plates not annealed permit a study to be made of the 
 defects that result from a lack of care in their manufacture. 
 
 The following should be observed in regard to 
 
 THE PLACE AT WHICH AND THE MANNEK IN WHICH TEST 
 PIECES SHOULD BE CUT OUT OF BOILEE PLATES, 
 
 notably in the case of plates that have already seen service : 
 
 A. PLANE PLATES, NOT WORKED. 
 
 In the case of plates with trimmed edges test strips for longitudinal and 
 trans verse bars will be taken from the edges,and in the case of untrimmed 
 plates at least 30 mm. inside of the edges. The cutting of the strips may 
 
20 
 
 be done either by means of shears or by sawing. Test strips cut from 
 bridge plates by means of shears must be straightened out cold under 
 pressure, or with wooden, copper, or leaden hammers; before dressing 
 them for tensile tests 5 mm. must be planed off on each side to remove 
 the traces of the shear cut; test strips cut from boiler plates by means 
 of shears will be treated in the same way. They will be annealed only 
 when especially desired. 
 
 U. PLATES WORKED ENTIRELY OR PARTIALLY, AND PLATES THAT HAVE BEEN 
 
 ALREADY IN USE. 
 
 (1) When the properties of the plate, before it was worked, are to be determined. 
 
 In this case, pieces out of which the test strips are to be cut should 
 be taken from the parts having uniform thickness and, as far as pos- 
 sible, plane surfaces. 
 
 If only a curved piece of plate can be obtained, then this will be 
 prepared by drilling and chiselling, or by means of the circular saw; 
 the test strips will be cut out of this piece in the same manner. From 
 plane pieces of plate, the test strips may be cut by means of shears, and 
 will then be treated as described above. 
 
 The curved test strips will be cautiously straightened under pressure, 
 or with wooden, copper, or leaden hammers, or with iron hammers by 
 interposing pieces of wood. 
 
 (2) When the mechanical properties of the plate, after having been worked, are 
 to be determined. 
 
 In this case it is impossible to give general rules either for the place 
 from which or for the manner in which the test strips are to be cut. 
 The principles according to which test pieces are cut out in the above- 
 described cases will be considered as much as practicable. 
 
 J. WIRE. 
 Wire should be subjected 
 
 1. To the tensile test. 
 
 2. To the torsion test, by means of machines excluding arbitrary 
 working. 
 
 3. To the bending test, by repeated bending to and fro with machinery 
 around a mandrel of 5 mm. diameter. 
 
 The use of a mandrel with a given diameter suppresses the bad method of clamping 
 wire and bending it to and fro in a vise with sharp edged jaws. 
 
 The permanent committee has been requested to submit a report at the 
 next convention on a new apparatus used in America for testing wire and 
 described by Mr. Henning, of New York, at tJtc conference of Vienna. 
 
 K. WIRE EOPE. 
 
 Wire rope should be tested 
 
 1. By tension. 
 
 2. By shock or impact, longitudinally. 
 
21 
 
 The bending test is valuable only when it is of long duration, but that is difficult 
 to obtain in practice, and is, moreover, snperiluons, since each wire in the rope has 
 already been tested by bending. 
 
 L. MEASUREMENTS TO BE MADE DURING TENSION TESTS. 
 
 1. During tension tests there should be measured 
 (a) The tensile strength. 
 
 (/>) The reduction of cross section at the point of rupture. 
 
 (c) The elongation after rupture (see M, No. 1). 
 
 (d) The limit of elasticity or of proportional elongation. 
 
 2. It is recommended that there should be obtained as many individ- 
 ual results as possible for the construction of the work diagram, unless 
 the same is traced by special apparatus. 
 
 3. In obtaining the diagram, special importance must be attached to 
 the determination of the velocity with which it was traced. 
 
 4. In obtaining work diagrams the five following points should be 
 determined as exactly as possible : 
 
 (a) Limit of proportional elongation, or of elasticity. 
 
 (b) Yield point. 
 
 (c) Commencement of contraction. 
 
 (d) Maximum load (fall of lever). 
 
 (e) Limit of rupture. 
 
 5. The area of the diagram must be calculated up to the limit of 
 rupture. 
 
 Practically, only that work is of importance which is done by the entire bar up 
 to the beginning of contraction. From that instant the principal work is done by 
 the contracting portion only ; but in the case of most materials of construction such 
 work is inconsiderable, so that no appreciable error is caused by determining the 
 area of diagram to the point of rupture. It appears, therefore, advisable to continue 
 this for the present, all the more as it is difficult to determine the moment of maxi- 
 mum load. Besides, it is desirable to take account of the portion of the diagram 
 corresponding to the event of contraction, because there may be relations between 
 the local elongation produced after the commencement of contraction and the work 
 required for it. 
 
 M. FORM OF TEST PIECES FOR TENSION TESTS. 
 
 1. Round bars for tests will be made in four types, viz, with diame- 
 ters respectively of 10, 15, 20, and 23 mm., according to the require- 
 ments and possibilities. The length of the cylindrical part, the 
 so called "actual length," should at each end exceed by at least 10 mm. 
 the "test length," viz, the length on which the elongation is to be 
 measured. In order that the percentage of elongation may be inde- 
 pendent of the form and dimensions of the cross section, the test length, 
 ?, should be made proportional to the square root of the cross-sectional 
 area, /. On the basis of the internationally adopted bar of 20 mm. 
 diameter, 200 mm. test, and 220 mm. actual length, this renders 
 
 I = 11.3 Vf~ 
 
22 
 
 The elongation should be measured on two diametrically opposite 
 sides of the bar, on each of the broken sections from the initial points 
 of the test length to the point of rupture and the mean taken of each 
 pair of measurements. 
 
 When rupture takes place outside the middle third of the test length, 
 that test should be rejected, or a process like the following must be 
 applied, which, however, presupposes that there is marked on the bar 
 not only its actual and its test length, but also a graduation to centi- 
 meters : 
 
 Let us suppose that in the case of the bar shown in fig. 2 the rupture 
 occurs between the fourth and the fifth graduation lines; then starting 
 from the point of rupture, the graduation lines are marked as shown in 
 the figure. To the left we now measure from 1 to 5 or from 1 to 10, accord- 
 ing to whether the elongation of 10 cm. or of 20 cm. is to be determined; 
 in each case the length 0-b and b-1 must also be measured. To the 
 right we can only measure from to 3, and to this has to be added the 
 piece corresponding to the missing one on the left side that is, 3-5 if 
 the elongation of 10 cm., and 3-10 if the elongation of 20 cm. is to be 
 
 IS 14 13 12 II 10 9 8 7 6 S 4 3 2 I 
 
 19 IB 17 16 15 14 13 12 II 10 9 6 7 65 432 I 
 
 FlO. 2. 
 
 determined. In this way the measurement of the bar is accomplished 
 very nearly as if the rupture had taken place in the middle of the 
 specimen. The above-mentioned graduation and the method of meas- 
 urement herein described must both be made on the two opposite sides 
 of the bar. 
 
 2. The actual and the test length of bars with rectangular section 
 depends on the area of the transverse section and should be computed, 
 as in the case of round bars, according to the formula: 
 
 Test length=Z=11.3 Vf 
 
 Likewise, the graduation of the bars and the method of measuring the 
 elongation after rupture is the same here as in the case of round bars. 
 It is recommended that the elongation of bars with rectangular section 
 should be measured on the two narrow sides as well as on one of the 
 wide sides, and that there should be given separately the mean of the 
 first two measurements and the result of the last- mentioned one. 
 
 3. If the width and thickness of the test pieces with rectangular sec- 
 tion can be chosen at will, there should be given for the width 30 mm. 
 and for the thickness 10 mm., and we should consider in general a sec- 
 tion of 30 bv 10 mm. as normal. 
 
23 
 
 In the place of the old width of bars of 50 mm. the width of 30 mm. will be exclu- 
 sively adopted, principally 011 account of the small testing machines used in smelt- 
 ing works, the power of which in most cases does not exceed 50 tons. 
 
 4. When thickness of material is given, as in the case of plates, then 
 for a thickness not exceeding 24 mm. there will be adopted for the test 
 pieces a width of 30 mm. From 25 mm. upward in thickness, thickness 
 will be taken as width, and there will be given to the test piece a thick- 
 ness of 10 mm. 
 
 In order not to lose in the last-named case the skin of the metal, 
 additional thickness will be given at the ends for the formation of the 
 bar heads for mounting. 
 
 When the machines are not powerful enough, the above limits of 24 
 and 25 mm. may be replaced in exceptional cases by the limits of 16 and 
 17 mm. 
 
 5. In flat iron, angle iron, T iron, channel iron, I beams, etc., test 
 pieces of 30 mm. in width as the maximum will be cut in the direction 
 of the length. In the case of great width of the flat iron, or of the 
 
 100 t 
 
 FIG. 3. 
 
 legs of the angle iron, or of the flanges and webs of I beams and chan- 
 nel irons, test bars will be cut out in successive lengths, as shown in 
 fig. 3, so that the entire cross section may be considered in the test. 
 
 G. The skin of the metal resulting from rolling must invariably be 
 preserved on the test pieces. 
 
 M". BENDma TESTS. 
 
 1. The slow- working mechanical contrivance by means of which bend- 
 ing tests will be made (see above, under Heading E) should fulfill the 
 following conditions: 
 
 It may either act by central pressure between two supports or by 
 lateral pressure on one of the ends of the specimen, the other being 
 held by the clamp. The apparatus should be simple and capable of 
 working rapidly. The part w,here the most strain takes place in the 
 test specimen should be clearly visible. The bending should take 
 place in a continuous way, and when it is done around a mandrel the 
 diameter of such mandrel should be as small as possible. 
 
 The test piece should have a rectangular section, the width of which 
 should be to the thickness as 3 to 1. The edges should be slightly 
 
24 
 
 rounded off. For rivet iron and square iron the cross section will 
 remain unchanged. 
 
 The red-hot test should be made as quickly as possible. In cold- 
 bending tests the rapidity is not important. 
 
 The angle of bending is not in itself sufficient to determine the defor- 
 mation of the test piece. One must also take into account the radius 
 of curvature on the convex side, which may be determined either directly 
 by means of templets or indirectly by measuring the elongation on the 
 tension face. 
 
 The permanent committee has been requested to devise the most suitable 
 and simple method of measurement. It has also been requested to study 
 the question of bending tests with injured specimens. 
 
 The permanent committee has, besides, been instructed to make an inves- 
 tigation into the causes of irregularities in the behavior of mild steel, 
 which often manifest themselves by unforeseen ruptures, etc., although 
 samples taken from the ends of ruptured bars, on being subjected to an 
 examination of quality, are found to be perfectly normal. Administration 
 authorities, etc., are requested, when a case presents itself, to place the 
 material at the disposal of the committee, in order that, together with an 
 exhaustive examination, its chemical composition may also be considered. 
 
 III. TESTS OF OAST IEOK 
 
 1. Test pieces of cast iron should have the form of prismatic bars of 
 110 cm. actual and 100 cm. test length and a cross section 3 cm. square. 
 They should be provided with an extension 25 by 25 mm. in cross sec- 
 tion, from which there can be cut, if it is deemed necessary, cubes 25 
 mm. high for compression tests. 
 
 Greater dimensions would be preferable for transverse as well as for tension tests, 
 but for the sake of conforming to Wacliler's fundamental experiments the dimen- 
 sions adopted by him have been retained. 
 
 2. The test pieces should be cast in a mold inclined 10 cm. per meter. 
 
 Wachlers test bars were cast vertical (it is not stated whether from the top or 
 bottom), but it has been noticed with some kinds of cast iron that castings become 
 too cold when they are cast from the bottom, and there is lacking experience in cast- 
 ing them from the top. The manner of casting also depends on the nature of the 
 cast iron, on the skill of the molders, foundry men, etc. 
 
 3. The height of pressure, measured by the height of the runner 
 stick, will be 20 cm. 
 
 4. Casting is done in dry sand molds. 
 
 5. There will be determined by the test 
 
 (a) The resistance to flexure up to the point of rupture and the cor- 
 responding work on three pieces. 
 
 (b) The tensile strength of round bars 20 mm. in diameter and 200 
 mm. in test length, made out of the broken parts obtained from the 
 test under a, two to be made out of each of the three bars tested there. 
 
 (c) The compressive strength of cubes 3 cm. (2.5 cm.) length of edge, 
 also made out of the broken parts obtained from the test under a, two 
 
25 
 
 to be made and tested out of each of the three bars tested there. The 
 pressure will be applied in the direction of the length of the original 
 test piece. 
 
 G. The faces of the test pieces for flexure and for compression will 
 retain the skin, as coming from the mold. 
 
 7. Special castings, such as supports of bridges, pipe, etc., will be 
 submitted to special tests conforming to the use to which they are to 
 be put. 
 
 IV. TESTS OF COPPER, BRONZE, A^D OTHER METALS. 
 
 1. COPPER. 
 
 To determine the quality of copper in plates, sheets, bars, and wire, 
 the following tests are deemed necessary: 
 
 A. Copper in plates, in sheets, and in bars: 
 
 (1) Tension test. 
 
 (2) Cold bending test. 
 
 (3) Hot bending test. 
 
 B. Copper wire : 
 
 (1) Tension test. 
 
 (2) Bending test. 
 
 (3) Torsion or twisting test. 
 
 CONDITION OF THE MATERIAL. 
 
 The tests will be made in the condition in which the material is deliv- 
 ered, or, if desired, those under A will also be made in its soft condition. 
 To determine the properties of the material in its natural state, it is 
 necessary to reduce the test specimen to the soft condition. For this 
 purpose the test pieces, after having been cut out, but before their final 
 shaping, will be heated in the furnace at a temperature of 600 to 
 700 C., but not beyond this, then cooled in the air until they are a dull 
 red, and finally plunged in water at a temperature of 15 C. 
 
 CUTTING OF THE TEST PIECES. 
 
 The test pieces must be cut out cold by means of a saw, file, or 
 machine tool, special care being taken that no subsequent straighten- 
 ing is required. When it does become necessary, straightening must 
 be done cautiously and, as far as possible, by means of copper hammers 
 or wooden mallets. If the test is to be made in the soft condition of 
 the material, then the test pieces, as cut out roughly, may be heated 
 for the purpose of straightening. In this case, however, they must be 
 heated once more in order to reduce them to the soft condition. 
 
 FORM AND FINISH OF THE TEST PIECES. 
 
 The test length I of test bars will be determined, as in the case of 
 wrought iron and steel (see II, M 1), according to the formula 
 
 1 = 11.3 VJ, 
 wherein / is the cross- sectional area of the bar. 
 
26 
 
 Iii the case of copper, the finishing of the test pieces has an exceed- 
 ingly great influence on the results of tests; therefore, the utmost 
 caution should be exercised in shaping test pieces into their final form, 
 special care being taken never to withdraw the cutting tool within the 
 limit of the test length, and also to cut only thin shavings toward the 
 end. The test pieces will be dressed in the direction of their length 
 and polished with emery. The sharp edges of the test pieces used for 
 transverse tests will be rounded with a file. 
 
 It is recommended also to give a round of 1 mm. radius to the edges 
 of the flat bars used for tension tests. 
 
 EXECUTION OF TESTS. 
 
 Tension tests, and the measuring of elongation, will be done as in 
 the case of iron and steel. 
 
 The cold bending test should be made over a mandrel with a diameter 
 equal to the thickness of the plate, of the sheet, of the bar, or of the 
 wire. It must not be made at a temperature below 10 0. In the case 
 of plates, sheets, and bars, those specimens that stood bending around 
 a mandrel up to 180 are then pressed together until the inner faces 
 come into close contact. The bending tests of wire will conform to 
 those prescribed for steel and iron wire. 
 
 The hot bending test will be made on bars brought to a cherry red 
 in a furnace. Those pieces will be bent until rents are produced or 
 until the interior faces touch. Torsion tests of wire will conform to 
 those prescribed for iron and steel wire. 
 
 2. METALS AND ALLOYS. 
 
 To determine the quality of the metals and alloys employed in the 
 construction of machines and railroads, in architecture, and shipbuild- 
 ing, the following tests should be made: 
 
 1. Tension tests. 
 
 2. Compression tests. 
 
 3. Transverse tests. 
 
 4. Hot and cold bending tests. 
 
 The tests will conform to those prescribed for cast iron or those pre- 
 scribed for copper according to the properties of the material to be 
 tested. In the first case, tests 1 to 3 are recommended; in the second 
 case, tests 2 to 4. 
 
 The permanent committee was directed to investigate the upsetting test 
 and to suggest rules for it, not only in the case of copper , brass, and other 
 metals, but also in the case of iron and steel. 
 
 V. TESTS OF WOOD. 
 
 1. In order to judge technically of the qualities of wood, as much as 
 possible of the following information should be procured : Statement of 
 the place of growth, whether the tree stood isolated or in a crowded 
 
27 
 
 forest, and from what part of the tree the test piece was taken. Finally, 
 a statement of the age and the time of cutting. 
 
 2. On account of the great difference existing between individuals 
 and between the different parts of the same tree, three samples at least 
 are necessary to render an opinion. 
 
 ;>. The outward appearance of each sample should be described as 
 follows: 
 
 A. For the longitudinal section, or, better still, for surface of natural 
 split, state 
 
 (<() Whether the fibers run straight or not. 
 
 (b) Whether there are knots ; if so, their nature. 
 
 B. For the transverse section 
 
 (c) In the case of ring-porous leaf trees and for all members of the 
 pine family state 
 
 (-) The mean width of the annual layers in millimeters. 
 (ft) The increase or decrease of width of annual rings in a radial 
 direction. 
 (;/) The form of annual rings, whether circular or eccentric. 
 
 (d) For trees with needle shaped leaves the approximate relation 
 between the part of the tree coming from the spring growth and the 
 part coming from the autumn growth, as apparent from the average of 
 annual layers. 
 
 4. There will be given for each specimen the specific weight not only 
 in the accidental condition of moisture existing during the test, but 
 also when air-dried that is, after having been dried at a temperature 
 of 101 to 105 0. There will likewise be determined the percentage 
 of moisture of each sample at the time of test, as compared with the 
 state of air- dry ness. (See above.) 
 
 5. The pressure test and the transverse test serve as a criterion of 
 the strength and the quality of the wood. 
 
 (a) The test of compression should be made on prisms 15 cm. long 
 and with a cross-section 10 cm. square, the test pieces to be mounted 
 centrally, the two end surfaces exposed to pressure being parallel. 
 
 (b) The transverse test will be made on prismatic bars 100 cm. long, 
 with a square section of 10 cm. by 10 cm. and a clear length of 150 cm. 
 between the points of support. In order not to injure the test piece 
 while making the test, there will be placed on it, at the point at which 
 the load is applied, a rider 2 cm. thick and 20 cm. long, and it will be 
 protected by still other means if deemed necessary. The flexure will 
 be pushed to rupture. The rupture of a few fibers or splinters will 
 not be considered as rupture of the piece. 
 
 (c) The strain at the moment of rupture should be calculated by 
 means of the formula used for flexure, the supposition being that it 
 holds good up to rupture. 
 
 (d) The quality is determined by the work corresponding to the flex- 
 ure of the specimen of the dimensions before given, the work being 
 
28 
 
 rated by a flexure diagram pushed or carried to the maximum value of 
 the effort of Hexure. 
 
 G. In order to obtain a correct mean for an entire trunk, the various 
 layers of which are different in character, there should be taken for the 
 pressure test as well as for the transverse test at least two specimens 
 from the heart and two specimens from the outer part of the tree, the 
 outer edges of the latter two being situated in the circumference of 
 the trunk. 
 
 7. The report of transverse tests should be completed by sketches 
 indicating for each test piece the position of the annual layers with 
 reference to the direction of the force acting on the piece. Sap wood 
 will be bent in the direction of the radius, from the center toward the 
 outside. 
 
 YI. TESTS OF SHIPBUILDING MATERIAL. 
 
 1. Shipbuilding materials of wrought iron, such as plates, angle, bar, 
 shape, and rivet iron, should be submitted to the following tests: 
 
 (a) Tension test. 
 
 (b) Cold bending test. 
 
 (c) Red-hot bending test or forging test. 
 
 2. Shipbuilding materials of mild steel, such as plates, angle, bar, 
 shape, and rivet iron, 'should be submitted to the following tests: 
 
 (a) Tension test. 
 
 (6) Cold bending test. 
 
 (c) Red-hot bending test or forging test. 
 
 (d) Tempering test and bending after tempering. 
 
 (e) It is recommended that those who employ mild steel in practice 
 should examine it witli regard to its welding properties. 
 
 Tension tests should be made on bars of standard dimensions cut 
 from the material just as it is delivered. The strips for bending tests 
 will be prepared in precisely the same way as described for testing of 
 boiler plates (see above under II, G- and H). The tempering test and 
 bending test after tempering will be made as in the case of boiler 
 plates, with this exception: The bending of the strips by a slow- 
 working mechanical contrivance will be done around an inner radius, 
 the size of which depends on the thickness of the plate. 
 
 VII. TESTS OF STONE. 
 A. STONE IN GENERAL. 
 
 Stone will be tested according to uniform principles from the point 
 of view of its resistance to boring and to quarrying. 
 1. Methods of testing: 
 The tests of resistance to boring will be made 
 
 (a) Either by means of. a jumper drill, or, 
 
 (b) l>y means of a rotary boring machine. 
 
 If the former is to be employed, it is recommended to take the one 
 used by the Saxon mining engineer Hausse, in Zankerrode, for testing 
 the resistance of stone to boring. It is described in the ki Deutsche 
 
29 
 
 Berg- und Hiittenmaimische Zeituug," 1882, Nos. 33 and 34. With this 
 machine or some similar one, or by means of a rotary boring machine, 
 the work required for the drilling of a hole of given dimensions is 
 determined in meter-kilograms. 
 
 2. Determination of the most favorable conditions for work before 
 undertaking resistance tests: 
 
 In the case of any given kind of stone, the minimum amount of work 
 required for a drill hole of given diameter is largely influenced by 
 
 (d) The moment of drop of the drill, or, in the case of the rotary bor- 
 ing machine, the amount of vertical pressure acting on the boring 
 tool, and its rotating velocity; again, 
 
 (b) The shape and cutting angle of the drill or of the teeth of the 
 borer, and 
 
 (c) The number of blows for one revolution of the drill when drilling 
 by impact. 
 
 Preliminary tests are therefore recommended for determining the 
 most suitable combinations. As a basis of those preliminary tests it 
 may be assumed that for a hole 25 mm. in diameter bored by impact 
 the most favorable moment of drop is comprised between G and 9 
 meter-kilograms, and that for the rotary boring machine the pressure 
 should probably vary between 30 and 130 atmospheres; also, that in 
 boring by impact the cutting angle should vary between 70 and 110 
 and the drill should be turned from one-thirtieth to one- sixth of the 
 entire circumference at each blow; finally, that for the rotary boring 
 machines at present in use the most favorable diameter of bore proba- 
 bly varies between 40 and 80 mm. 
 
 3. Special uniform directions : 
 
 After the most suitable methods of test of a given kind of stone have 
 been determined by means of the above preliminary tests, then the 
 diameter of drill hqle for drilling by impact shall be fixed at 25 mm., 
 corresponding to the mean diameter of the one-man drill hole. In order, 
 however, to determine whether the amount of work required per unit 
 of drill-hole space is dependent on the diameter of the hole, there shall 
 also be employed larger diameters. It is recommended to use as such 
 35, 45, and G5 mm., corresponding to the mean diameters of the two- 
 man, three-man, and machine drill holes. After having determined 
 empirically the most favorable moment of drop for a hole of 25 mm., 
 there will be applied the law of proportional resistance to find those 
 which correspond to the above greater diameters of drill holes. 
 
 For rotary borings no uniform diameter can be recommended for the 
 holes on account of the varieties of the existing boring machines. 
 However, it should be sought to approach as near as possible the 
 diameters of 45 and 05 mm., recommended for drilling by impact. 
 
 4. Other tests: 
 
 For the purposes of information, it is desirable that the rocks sub- 
 jected to the test of resistance to boring should also be submitted to 
 tests of compression, elasticity, and shearing. 
 
30 
 
 5. Table of borings: 
 
 The following form should be employed uniformly to record the results 
 of the tests : 
 
 STANDARD RECORD BLANK FOR BORING. 
 
 1. Description of rock from a geological and mineralogical point 
 
 of view. 
 
 2. Miner's classification (bard, very hard, extremely hard). 
 
 3. Texture (for instance, coarse grained, fine grained, layers par- 
 
 allel, perpendicular, or oblique to axis of hole bored). 
 
 4. Specific gravity of rock. 
 
 5. .Diameter of drill hole when drilling by impact. 
 
 C. The diameter of hole and core in the case of a rotary boring 
 machine. 
 
 7. Straight or curved edge drills in drilling by impact. 
 
 8. Cutting angle when drilling by impact. 
 
 9. Number of blows in one revolution of drill when drilling by 
 
 impact. 
 
 10. Falling weight when drilling by impact. 
 
 11. Mean height of drop when drilling by impact. 
 
 12. Number of blows that were inquired to obtain observed depth 
 
 of drill hole. 
 
 13. Number and form of cutting teeth in the rotary drill. 
 
 14. Statement of pressure and of velocity with which the rotary 
 
 machines were worked. 
 
 15. Depth of drill hole. 
 
 10. Calculated or indicated drill work done, in meter-kilograms, 
 per cubic centimeter of drill-hole space. (In the case of 
 rotary boring only the annular space will be counted.) 
 
 B. BUILDING STONE. 
 
 a. NATURAL BUILDING STONE. 
 
 1. Besides the petrographic and geologic designation of the stone 
 there must be named the quarry as well as the bench Avhence the speci- 
 men comes. There must also be given the date of their quarrying and 
 consequently of their storage in the depot. In the case of great damp- 
 ness of the quarry, the quarrying should be done in the dry season. 
 
 As it is sometimes difficult for those who make the tests to verify the 
 exactitude of the statements made by the owners of the samples in 
 regard to their mineralogical designation, it is recommended that this 
 test, unless expressly demanded, be left out entirely and a statement 
 to this effect made in the certificate of test. On the other hand, it is 
 well to correct striking errors in the designation of rocks by notifying 
 the interested parties in regard to them. 
 
 Likewise there may be omitted in certain cases the verification of the 
 statements as to the quarry and the bench from which the sample has 
 
31 
 
 been taken, the certificate of test with reference to these points then 
 being worded about as follows: "Said to be taken from - - quarry 
 and bench." 
 
 2. It is recommended that those who are in charge of the tests should 
 inform themselves before making them as to the use to which the appli- 
 cant desires to put the materials (building stone, freestone, flagging, 
 ballasting, paving), and to base tests on that information and not on 
 the wording of the order. 
 
 3. Stone to be used for freestone for structures or substructures should 
 be tested for compression in the form of cubes with planed faces. These 
 cubes should be placed between compression plates without any inter- 
 posed material. One of those plates should move easily in every 
 direction. 
 
 According to the use to which the material will be put, the resistance 
 to compression will be tested normally or parallel to the bed, or in both 
 directions. Tests will be made on at least three samples for each 
 direction. 
 
 The samples should be made as large as the strength of the material 
 and the maximum power of the testing engine may permit, 10 cm. length 
 of edges being, however, sufficient for stones of inferior strength. 
 
 4. There should be measured during the tests, if possible at regular 
 intervals of pressure, the corresponding loss of height of the test 
 pieces, in order to be able to draw the diagram of work. There will be 
 made also in a similar way tension and transverse tests. 
 
 5. Before use, the test pieces should be dried in a temperature of 30 
 G. until their weight is constant. 
 
 G. There will be determined always the specific gravity (weight of 
 unit of volume), and that after drying at 30 C. 
 
 7. The test of frost resistance will be made on specimens of uniform 
 dimensions, as the absorption of water and the action of frost depend 
 upon the extent of the surface. In view of the dimensions of cement 
 test pieces, a cube 7 cm. in length of edge is selected here. Only iu 
 the case of very hard stone, smaller dimensions may be admitted as an 
 exception; however, in cases of this kind there is very rarely any doubt 
 about the resistance of the stone against frost. 
 
 8. The frost test comprises : 
 
 (a) The determination of compressive strength in a water- saturated 
 state and its comparison with the same strength when dry. 
 
 (b) The determination of the compressive strength of the stone redried 
 after 25 successive freezings and thawings, and the comparison of that 
 strength with the compressive strength when dry. 
 
 (c) The determination of the loss of weight resulting from 25 freezings, 
 keeping account of the fragments mechanically separated by the frost 
 and of the substances soluble in a given quantity of water. 
 
 (d) The examination of the frozen stone by means of a magnifying 
 glass, especially to ascertain whether there are produced fissures or 
 splinters. 
 
32 
 
 0. For the freezing test there will be employed: 
 
 For compression tests in a dry state specimens, 3 of which are per- 
 pendicular and 3 parallel to the bed, unless indeed those tests have 
 already been made (see above under No. 3). On account of the law of 
 proportional resistance, test pieces with a greater length of edge than 
 7 cm. may be used. 
 
 For compression tests in a water- saturated state, but not frozen, 6 
 specimens, 3 of which will be crushed perpendicular and 3 parallel to 
 the bed. 
 
 For freezing tests, 6 specimens, 3 of which will finally be crushed 
 parallel and 3 perpendicular to the bed. 
 
 10. In the execution of frost tests the following details should be 
 taken into account: 
 
 (a) For absorption of water the cubes will first be immersed to a depth 
 of 2 cm., and then gradually submerged completely. 
 
 (b) There will be used for this immersion distilled Avater at a temper- 
 ature of from 15o to 20 0. 
 
 (c) The test pieces saturated with water will be exposed to a temper- 
 ature of from 10 to 15 0. 
 
 (d) The duration of exposure to cold will be four hours each time. 
 The test pieces will be thus exposed when completely saturated with 
 water. 
 
 (c) For thawing there will be used a given quantity of distilled water 
 at a temperature of from 15 to 20 0. 
 
 11. The stone having been subjected to the frost test, no additional 
 test of its weather- wearing qualities is required; but it is desirable to 
 carefully observe phenomena of this kind occurring in nature, and to 
 collect experiences made on material in actual service. There should 
 be observed especially the influence of 
 
 (a) The sun, with respect to splitting and cracking. 
 
 (b) The air, with respect to the carbonic acid it contains. 
 
 (c) Kaiii and humidity, with respect to lixiviation and decomposing 
 stones. 
 
 (d) Temperature. 
 
 p. ARTIFICIAL BUILDING STONE. 
 
 a a. BRICKS. 
 
 1. For testing a lot of bricks, the least-burned ones should always 
 be selected. 
 
 2. The bricks will be tested for compression in pieces of approxi- 
 mately cubical shape, obtained by superposing two half bricks and 
 binding them together by a thin bed of mortar of pure Portland cement. 
 The pressure surfaces will be smoothed by a similar layer of the same 
 mortar. At least G specimens will be tested. 
 
 3. The specific gravity of the bricks will also be determined. 
 
 4. To verify the uniformity of the material the degree of the porosity 
 
33 
 
 of the bricks will be determined. For this purpose they are first dried 
 and then immersed in water until saturated. Ten pieces are thus com- 
 pletely dried on a plate of iron and weighed. They are then placed in 
 water for 24 hours, the water not reaching above half the thickness of 
 the bricks j after that they are completely submerged for another 24 
 hours; then, after the surfaces have been wiped, they are weighed 
 again. There is thus obtained the mean quantity of water absorbed. 
 The absorption should always be calculated in volume, but there will 
 be indicated also the per cent in weight of water absorbed. 
 
 5. The test of frost resistance will be made in the following ufanner : 
 (a) Five of the preceding bricks saturated with water will be tested 
 
 in that condition for compressive resistance. 
 
 (6) The five others will be placed for 4 hours in a refrigerator, the 
 temperature of which is at least 15 0. They are then taken out and 
 thawed in water at 20 0. The parts that spontaneously break off 
 will remain in the thawing vase until the end of the operation. The 
 freezing is repeated 25 times. The detached particles are dried and 
 weighed, and the weight obtained is compared with the original weight 
 of the brick, which latter will finally be examined under a magnifying 
 glass to ascertain whether there are any fissures or splinters. 
 
 (c) After freezing the bricks a compression test will be made. For 
 this purpose they will be dried. The result will be compared with that 
 of the compression test made on dried bricks. (See above under No. 2.) 
 
 (d) The experimental freezing of bricks does not permit us to judge 
 absolutely of their resistance to freezing. The value of those experi- 
 ments is only relative, because they only permit us to recognize the 
 bricks most destructible by frost. 
 
 6. To test bricks with regard to their containing soluble salts, five of 
 the least-burned ones of the lot which have not yet been in contact 
 with water are selected. Only the interior is utilized, for which pur- 
 pose the bricks are split in three directions and the interior edge 
 chipped off from each of the eight pieces thus obtained. These edges 
 are pulverized fine enough to pass through a screen of 900 meshes per 
 square centimeter ; then the fine dust is removed by means of a sieve 
 of 4,900 l meshes to the square centimeter, and the remaining materials 
 are used for the test. Of this there will be taken 25 grams, which will 
 be mixed with 250 cubic cm. of distilled water. This will be boiled for 
 an hour, replacing from time to time the evaporated water. Then it 
 will be filtered and washed. The quantity of soluble salts contained 
 in the brick will then be determined by evaporating the solution and 
 glowing the residue. The quantity of soluble salts will be indicated in 
 per cent of weight of the brick. 
 
 The salts thus obtained should be submitted to a quantitative 
 analysis. 
 
 1 These are the same sieves as those employed for cement tests. (See below under 
 VIII, C 2.) 
 
 10389 3 
 
7. The tests as to the contents of carbonate of lime, pyrites, selenite, 
 and other similar materials, should first be made on the uuburnt clay. 
 For that purpose there will be furnished two bricks not burned. These 
 bricks will be soaked in water and the coarse parts removed by passing 
 through a screen of 400 meshes per square centimeter (about one-third 
 of a millimeter clear width of meshes). The sand thus obtained will be 
 'examined as to its mineralogical components by means of a magnifying 
 glass and by treating it with muriatic acid. If impurities are found in 
 it, such as carbonate of lime, pyrites, selenite, etc., samples of the burnt 
 bricks for instance, the remnants of the test for soluble salts will be 
 tested in Papiii's digester as to the possible injurious influence of such 
 impurities. They will be placed in Papin's digester in such a manner 
 as not to come in contact with the water, but only with the steam ; the 
 pressure of that steam should be one-quarter of an atmosphere and the 
 test should last three hours. There will then be determined, by exami- 
 nation with a magnifying glass, whether any splintering has taken 
 place. 
 
 ft ROOFING TILES. 
 
 1. When roofing tiles are to be tested, the information concerning 
 them should comprise maximum and minimum dimensions. 
 
 2. To determine its specific weight, the material will be pulverized, 
 that portion of the powder being used which has passed through a sieve 
 of 900 meshes per square centimeter and has been retained by a sieve 
 of 4,900 meshes to the square centimeter. This determination will be 
 made by means of a volumenometer. 
 
 3. The weight per unit of volume of the solid fragment will be deter- 
 mined by the hydrostatic method that is, by measuring the volume of 
 water displaced by the saturated fragment. Where considerable loss 
 is apt to be caused through lixiviation, the weight will be determined 
 by means of the volumenometer, the test pieces being coated with 
 paraffin. 
 
 4. Examination of the capacity for absorption, 
 
 5. Determination of the salts soluble in water, and 
 
 G. Examination in regard to injurious admixtures, such as slakable 
 lime, etc., will be made in a similar way to the case of tiles and bricks. 
 (See above under a a, Nos. 4, 6, and 7.) 
 
 7. Examination of the capacity for absorption of the surface of the 
 tile and of its permeability will be made as follows : 
 
 Fragments will be selected of such dimensions that they can absorb 
 from 20 to 25 cubic cm. of water. Those fragments will be dried, and 
 their edges will be coated with wax. Finally, there will be affixed on 
 one of their surfaces, by means of wax, cylindrical tubes of 10 square 
 cm. cross section. 
 
 The following observations are then made: 
 
 (a) The 'time necessary for the absorption of 10 cubic cm. of water 
 introduced into each tube by means of a little pipe. 
 
35 
 
 (&) The time necessary to produce sweat on the lower surface of the 
 fragment after a new introduction of 10 to 15 cubic cin. of water. 
 
 (c) The time necessary for the formation of drops on the lower face 
 after a new introduction of 10 cubic cm. of water, and the quantity of 
 water collected in case of permeability in a vessel placed under the 
 fragment. 
 
 8. To determine the transverse strength of roofing tiles, two bands of 
 Portland cement, 1 cm. in width and 20 cm. apart, will be run across 
 the lower face. A similar band will be run across the upper surface 
 of the tile, mid way between the two lower ones. The latter will serve 
 as supports of the tile during the test, while the upper band will receive 
 the load. 
 
 C. PAVING AND BALLAST MATERIAL, NATURAL AND ARTIFICIAL. 
 
 1. Information regarding the petrographic and geologic nature of the 
 material, its origin, etc. 
 
 2. Information concerning the use to which it is to be put, the same 
 as for natural building stone. (See above under B, a.) 
 
 3. Determination of the specific weight of the samples. 
 
 4. All road-making materials that will be exposed to frost when in 
 actual use should be subjected to frost tests, according to the rules 
 given for natural building stone. (See above under B, a, Nos. 7 to 10.) 
 
 5. The best test for sidewalk stones consists in determining their 
 resistance to wear. For this test it is recommended to employ the 
 process published by Professor Bauschinger in No. XI of his* Mit- 
 theilungen. 
 
 For burnt stone the regularity of wear from the outer skin toward 
 the interior should be determined by repeated tests on the same sam- 
 ple. Those tests must not be confined to a single sample of the material 
 to be tested ; in fact it is necessary to select for testing from the 
 entire lot samples of the least, of medium, and of the best quality it 
 contains. 
 
 6. The value of paving materials, enrockment or macadam, can be 
 determined conclusively only by the construction of trial roads, sub- 
 jected to a traffic, in kind and weight as uniform as possible, per meter 
 of width. It is highly desirable that as many as possible of such trial 
 roads should be constructed, all according to a uniform plan. In refer- 
 ence to this question, special attention is invited to the publication by 
 Professor Dietrich on "Materials of construction for stone roads." 
 
 7. In order to determine the quality of new paving materials more 
 rapidly than is possible by their introduction into trial roads, and also 
 in order to obviate the necessity of constructing a separate trial road 
 for each new material, a more rapid process for testing stone is 
 required. Materials for pavement and broken-stone roads being sub- 
 jected at once to wear and to breakage, it is recommended to test them 
 in revolving drums such as have been used for a long time in France, 
 
36 
 
 and are described in the above-mentioned publication of Professor 
 Dietrich; but with a view of augmenting the intensity of the shock, the 
 dimensions of those drums should be increased, giving them a diameter 
 of 30 cm. and a height of 50 cm. The velocity of rotation should also 
 be increased. 
 
 It should be remarked here that the preparation of the broken -stone 
 samples must not be left to the applicant, but for the sake of uniformity 
 should be done by those making the tests. 
 
 On account of the perpetually changing conditions of the drill the 
 above test is preferable to the drilling test, and pains should be taken 
 in practice to compare its results with the results obtained by the con- 
 struction of trial roads. 
 
 8. Besides this drum test, compression tests should also be made, 
 notably on enrockment materials, which are always exposed to crushing. 
 This test will be made on cubical specimens having a uniform length of 
 side of from 5 to 7 cm. 
 
 9. Paving stones should be tested with regard to the tendency to 
 wear smooth. 
 
 10. For paving and enrockment materials it likewise appears neces- 
 sary to select samples for test from the worst, the mean, and the best 
 of the lot, as for those materials homogeneousness of grain is almost 
 the principal factor. 
 
 11. Tests of asphalt can be made exhaustively only by the construc- 
 tion of trial roads. To be able to give a suitable opinion of the results 
 of that test it is necessary 
 
 (a) To determine the quantity and the quality of bitumen contained 
 in the asphaltum, whether natural or artificial. 
 
 (6) To determine physically and chemically the residue. 
 
 (c) To make tests of specimens of the same specific density as the 
 street material employed, by means of Yicat's standard needle of 1 
 square cm. circular cross section. 
 
 (d) To determine the wear of such pieces by abrasion. 
 
 (e) To determine the resistance to frost of those specimens. 
 
 D. TESTS OF PRESERVATIVES FOR NATURAL AND ARTIFICIAL 
 
 STONE. 
 
 1. The tests of natural and artificial building stone from the point of 
 view of their preservation should be made by tension. 
 
 All results obtained up to the present from the testing of preservatives agree in 
 demonstrating that they always tend to produce an increase of strength, or, at any 
 rate, a diminution of the loss of strength caused by saturation and repeated freezing. 
 As all materials used for preservation form surface coatings and do not fully per- 
 meate the stone, it appears proper to employ for the tensile tests test pieces of small 
 cross-sectional area. Great size of surface as compared with volume will make the 
 action of preservatives more pronounced and is, therefore, an additional reason for 
 the above form of test pieces. 
 
37 
 
 2. The normal German standard of 5 cm. of minimum cross section 
 will be adopted for the test pieces. 
 
 All natural building stones which are in need of preservatives being soft, there is 
 no difficulty in giving them the standard form. For shaping artificial stone the 
 German pattern can be used. 
 
 The German testing machine is directly adapted for the tension testa. 
 
 3. Three specimens are sufficient for each series of tests. Where 
 important anomalies are found five additional specimens will be tested. 
 
 4. The method of testing- the resistance to frost prescribed for nat- 
 ural and artificial stone under No. VII, B a and No. VII, B ft will also 
 be applied to the testing of preservatives. Besides that, tests are 
 recommended for the purpose of determining the durability of the pre- 
 servative effect. In practice it may be sufficient to repeat the above 
 tests after one, three, and five years. 
 
 5. There may exist preservatives the action of which consists not so 
 much in increasing the strength of the stone as in protecting it against 
 atmospheric destructive agents through obstruction of the surface pores. 
 In these cases the apparent porosity should be determined by measur- 
 ing the capacity of absorption of uniform test pieces, in percentages of 
 their weight, before and after having been treated with the preservative. 
 
 6. The application of the preservative material to the test pieces 
 should conform to the method in which that product is used in prac- 
 tice. It is recommended that the treatment should vary according to 
 the nature of the preservative, as the method of its use may also exer- 
 cise a considerable influence on its action. 
 
 VIII. TESTS OF HYDRAULIC BINDING MEDIA. 
 
 A. GENERAL REMARKS. 
 
 1. When it is a question of binding media intended for a given pur- 
 pose, the test should be made with respect to such purpose as well as 
 with respect to the available materials used in mixing (such as sand, 
 gravel, slag, etc.). Those tests must not be replaced by those known 
 under the name of "standard tests." 
 
 Sewer pipes and covers should be tested according to the methods 
 of Professor Bauschinger. (See Mittheilungen aus dein mech. tech. 
 Laboratorium der tech. Hochschule in Miinchen, Heft VII.) 
 
 2. The tensile and compressive strength as derived at present from 
 standard tests does not by itself furnish conclusive evidence in regard 
 to the durability of structures. This is influenced to a very great 
 extent by other important factors, such as resistance to weather, 
 impermeability to water, adhesive strength, and constancy of volume. 
 It being impossible to fully utilize the strength so far already obtained 
 for cement mortars, it does not appear necessary to seek to increase it. 
 
38 
 
 B. NOMENCLATURE. 
 
 1. Hydraulic limes are products obtained by the calcination of lime- 
 stones containing more or less clay or silicic acid, and which, sprinkled 
 with water, are slaked entirely or partially into powder. According 
 to local cireumstances, the lime is delivered in commerce in the form of 
 lumps, or, hydrated, in the form of powder. 
 
 2. Roman cements are products obtained by the calcination, below 
 the verge of vitrification, of marl containing much clay. They do not 
 slake when sprinkled with water, and it is necessary to employ mechan- 
 ical means to reduce them to powder. 
 
 3. Portland cements are products obtained from the calcination, up to 
 the verge of vitrification, of natural marl, or of artificial mixtures of 
 substances containing clay and lime. They are reduced to powder by 
 grinding, and contain at least 1.7 parts, by weight, of lime for 1 part of 
 the material which gives to tbe lime its hydraulic property. To regu- 
 late certain properties of technical importance, there may be added 
 foreign material up to 2 per cent of the weight without this addition 
 necessitating any change of name. 
 
 4. Hydraulic admixtures are natural or artificial materials which 
 generally do not harden under water when alone, but only when mixed 
 with caustic limes. Such are Pozzuolana, Santorin earth, trass obtained 
 from certain volcanic tufa, furnace slag, burnt clay, etc. 
 
 5. Pozzuolana cements are products obtained by intimately mixing 
 powdered hydrates of lime with hydraulic mixtures, ground to the fine- 
 ness of dust. 
 
 6. Mixed cements are products obtained by intimately mixing manu- 
 factured cements with suitable admixtures. Such binding media should 
 be formally designated as mixed cements, with an indication of the 
 materials entering into their composition. 
 
 O. TESTS. 
 
 1. Weight. 
 
 (a] The determination of the specific weight of hydraulic binding 
 media that is to say, of their grains will be made uniformly by means 
 of the so-called volumenometer. 
 
 (b) For the determination of volume weight (or apparent density) of 
 a hydraulic binding medium there will be used a standard cylindrical 
 vase of the capacity of one liter and 10 cm. in height, into which the 
 material will be passed, as follows : 
 
 (a) Passed in mechanically through a sieve by means of a Tetmajer 
 apparatus. 
 
 (/?) Shaken in mechanically by means of a Tetmajer apparatus. 
 
 (y) Poured in by hand, making use of a funnel apparatus for filling, 
 and of the standard liter vase. 
 
 2. Fineness of grain. The fineness of grinding in hydraulic binding 
 media will be determined by means of screens from 900 to 4,900 meshes 
 per square centimeter for Portland cement, and from 900 to 2,500 
 
39 
 
 meshes per square centimeter for the other hydraulic binding media, 
 the quantity to be employed for each test being 100 grams. The wire 
 of the screens should have the following dimensions: 
 
 For screens of 4,900 meshes, 2,500 meshes, and 900 meshes per square 
 centimeter, the diameter of wire will be respectively 0.05, 0.07, and 
 0.1 mm. It is recommended always to employ screens from the same 
 makers. 
 
 3. Conditions of setting. 
 
 a. FOR ALL HYDRAULIC BINDING MEDIA EXCEPT POZZUOLANA (TRASS). 
 
 (a) The study of the conditions of setting should always be made at 
 a temperature of from 15 to 18 0. 
 
 (b) The investigations should be made on a paste of normal consist- 
 ency. To determine that consistency there will be used the standard 
 needle combined with the consistency measure, which is composed of a 
 rod 1 cm. in diameter, with a weight of 300 grams, and a cylindrical 
 box 8 cm. in diameter and 4 cm. high, made out of a substance imper- 
 meable to water and a nonconductor of heat (preferably hard rubber). 
 
 To determine the normal consistency there should be mixed 400 grams 
 of the hydraulic binding medium with a certain quantity of water, so as 
 to form a thick paste, which will be worked by means of a spatula in 
 the form of a spoon for exactly 3 minutes for the slow-setting cements 
 and for 1 minute for the rapid-setting cements. This paste is then 
 placed into the box without shaking, and after smoothing the surface 
 the rod is cautiously rested on it and allowed to sink into the paste. 
 The consistency of the paste will be considered a standard one if the 
 progress of the rod is arrested at a height of 6 mm. above the bottom of 
 the box. 
 
 (c) The conditions of set will be determined by a standard needle 
 weighing 300 grams and having a circular section of 1 square mm., and 
 with the same box as above. 
 
 Four hundred grams of the binding medium to be tested are mixed 
 to a paste with the quantity of water previously determined, as shown 
 under &, the duration of working the paste being (as under b) 3 minutes 
 for slow-setting and 1 minute for quick-setting binding media; then the 
 paste is filled into the box as above. 
 
 Hardening has commenced when the needle can no longer completely 
 penetrate the material. For rapid-setting material the commencement 
 of hardening can also be determined by means of the thermometer. 
 
 To determine the duration of set the box will be turned over. All 
 hydraulic binding media may be considered as having set when the 
 standard needle no longer leaves any imprint on the cake of mortar. 
 The time necessary to obtain that result is termed the " duration of 
 set." 
 
 The designation of hydraulic binding media as quick or slow setting 
 is governed by the commencement of hardening. 
 
 (d) The following test maybe made preliminary to the determination 
 
40 
 
 of the duration of set. There are mixed 100 grams of the cement to 
 be tested with the water necessary to form a paste of normal con- 
 sistency, which is worked for 3 minutes or 1 minute, according to 
 \vhether the material is slow setting or quick setting, and then spread 
 on a glass plate in a cake about 2 cm. thick. This cake may be con- 
 sidered as set as soon as it resists a slight pressure of the finger nail. 
 
 (e) Besides testing the conditions of set with pastes of standard 
 consistency, it is desirable that they should also be tested with paste 
 prepared with greater quantities of water. 
 
 /?. FOR POZZUOLANA (TRASS). 
 
 Pozzuolana reduced to fine powder and dried at a temperature 
 between 100 and 110 C. is tested from the point of view of the loss of 
 water of crystallization by calcination, and from the point of view of 
 the commencement of hardening under' water, by means of a normal 
 needle of 300 grams with a circular section of 1 square millimeter. 
 (See above under a c.) This last test is made as far as possible at the 
 temperature of 15 C.; at any rate a record of the temperature will be 
 kept, the mixture used for the test being 2 parts by weight of Pozzuo- 
 lana, 1 part by weight of hydrate of lime in powder, and 1 part by 
 weight of water. This mortar, filled into the box and smoothed off, 
 will be immediately submerged in water and tested after two, three, 
 four, and five days to determine the weight under which the above 
 standard needle will completely penetrate it, the box used not being 
 higher than 4 cm. 
 
 4. Constancy of volume. 
 
 (tv) Portland cement. 
 
 (a) To determine rapidly the constancy of volume of Portland cement 
 when hardening in water or under conditions preventing it from 
 becoming dry the following test is recommended: 
 
 The cement is mixed with water to a paste of standard consistency 
 and then spread on a plane thin glass plate so as to form cakes of from 
 8 to 10 cm. in diameter and about 2 cm. thick. Two of those cakes, 
 which must be protected against desiccation to avoid cracking, are 
 placed after 24 hours, but under no circumstances before they have 
 set, on a metallic plate, plane side down, and submitted to a tempera- 
 ture from 110 to 120 0. until evaporation ceases (but at least for 1 
 hour). 
 
 If after that operation the cakes show neither warping nor cracks 
 on the edges, the cement may be considered as possessing constancy 
 of volume ; otherwise recourse must be had to the cake test on glass 
 plates, which is at present universally employed and considered 
 decisive. 
 
 The presence of more than 3 per cent of anhydrous sulphate of lime 
 (or the corresponding portion of unburnt gypsum) will prevent the 
 above-described test from being conclusive. 
 
41 
 
 (b) The decisive test for constancy of volume is that of the cakes 
 on glass plates. It is made in the following manner: 
 
 One hundred grams of the cement to be tested are mixed with water 
 to a paste of standard consistency and then spread on a plane glass 
 plate into a cake 2 cm. thick. Two cakes thus obtained, and protected 
 against desiccation to avoid cracking, are placed in water after 24 hours, 
 but certainly not before having set. The cement tested may be con- 
 sidered as possessing constancy of volume if at the end of 28 days the 
 cakes do not show any warping or cracks on their edges. 
 
 (c) The boiling test may undoubtedly be considered as the most con- 
 clusive and rapid test for the determination of constancy of volume of 
 Portland cement, of slag cement, and of trass. 
 
 The boiling test, as described below, has been referred to the subcom 
 mitteefor examination and report. 
 
 Fifty grams of the cement to be tested are mixed to approximately 
 standard consistency that is, with 13 to 15 grams of water and after 
 having been worked for 1 minute are spread on a glass plate into a cake 
 1 cm. thick in the middle and thinning out toward the edges. This cake is 
 kept for 24 hours in a covered receptacle, saturated with steam, then placed, 
 either after having been detached from the glass plate or together with it, 
 into a bath of cold water, which is slowly brought to the boiling point that 
 is, say, in about 10 minutes the lid being kept on in order to reduce evapo- 
 ration. The cakes should be entirely submergedin the boiling water; ichen 
 any water has to be added, this should be done in small quantities, so that 
 the boiling point is quickly restored. 
 
 It is, moreover, recommended to the permanent committee to consider 
 also the mixtures of cement and sand in their investigations of methods for 
 determining constancy of volume. 
 
 From the experiments of Professor Bauschinger it was found that cements which 
 had given favorable results by the "standard-cake test" (see above under b) not 
 only after 28 days but also after six months and a year would fail when mixed in 
 thti proportion of 1 to 3 and formed into prisms of 5 square cm. cross section and 12 
 cm. length ; expansion was perceptible after six months in Bauschinger's apparatus 
 and after a longer period also with the naked eye. 
 
 (#) Hydraulic limes and Koman cements: 
 
 (a) For those materials the cake test under water, described before 
 under a, b is recommended. 
 
 (b) The study of the boiling test (see under a, c) has been assigned to the 
 permanent committee. 
 
 (y) Pozzuolana (trass). 
 
 (a) For these the following method is recommended: A mixture of 2 
 parts by weight of Pozzuolana (trass), 1 part by weight of hydrate of 
 lime in powder, and 1 part by weight of water is placed into a strong 
 metallic box (say of galvanized iron) open at the top, slightly conical 
 in shape, from 3 to 4 cm. in height and from 6 to. 8 cm. in diameter on 
 top; after the mixture has been leveled off, the box containing it is 
 immediately placed into a receptacle full of water, so that the upper 
 edge of the box is submerged to a depth of 2 cm. The hardening 
 
42 
 
 mortar should neither rise above the edges of the box nor should it 
 swell in the middle, arch-like. The bottom of the box should be solid, 
 in order that the mortar may expand upward only. 
 
 (b) The boiling test may undoubtedly be considered the most reliable 
 and the most rapid test for determining constancy of volume, even 
 when the material is trass (see above under a c). 
 
 5. Tests of strength. 
 
 (a) For all hydraulic binding media with the exception of Pozzuo- 
 lana: 
 
 (a) The tests of strength will be made on a mixture of 1 part by 
 weight of the binding medium with 3 parts of sand. It is desirable, 
 however, that tests should also be made with greater admixtures of 
 sand. 
 
 (b) The sand employed should be standard sand obtained from quartz 
 sand> as nearly pure as possible. 
 
 The official standard that is to say, the sand to which all compari- 
 sons are referred is Freienwalde sand which passes through a sieve of 
 60 meshes and is held by one of 120 meshes per square centimeter. 
 
 For other countries outside of Prussia it is optional to procure their 
 own standard sand, selecting it, however, if possible, so that its influ- 
 ence on the strength of mortar is the same as that of the standard 
 Freienwalde sand. Where that is impossible, judicious coefficients of 
 comparison should be determined. 
 
 (c) The wire diameters of the above sieves should be as follows: 
 Screen of 60 meshes, 0.38 mm. in diameter; screens of 120 meshes, 
 0.32 mm. in diameter. 
 
 (d) The volumetric weigh t^of the standard sand will be determined 
 by means of the standard liter into which the sand is passed from the 
 sieves. 
 
 (e) The decisive test of strength is the compression test. It is made 
 on cubes 5 square cm. in section. 
 
 (/) The ordinary test of quality (the test controlling the delivery of 
 materials) is the tension test made by means of the standard German 
 apparatus on test specimens of German standard form with a cross 
 section of 5 square cm. 
 
 (g) The determination of standard consistency of mortar and the search 
 for a suitable mechanical method of malting test pieces^ especially with a 
 view of obtaining equal density of the test pieces for tension and compres- 
 sion^ remains referred to the permanent committee. 
 
 For the present, test pieces for tension and compression may be made 
 by hand, but as far as possible of the same degree of density. 
 
 (h) To determine resistance to tension and compression, six test 
 pieces of equal age are required for each series. The arithmetical 
 mean of the four highest values obtained will be considered as conclu- 
 sive. 
 
 (i) All test pieces must be kept for the first 24 hours in a receptacle 
 saturated with steam j after that, and up to the time of testing, they 
 
43 
 
 will be kept submerged in water, the temperature of which ranges 
 from 15 to 18 0., and which will be renewed every 7 days. 
 
 (A*) The 28-day test is considered conclusive for all binding media. 
 
 To judge of the quality in a shorter time there may be determined in 
 the case of Portland cement the strength of a mixture of 1 to 3 after 7 
 days. 
 
 Concerning the determination of quality in a yet shorter time, viz, 
 in 3 days, the convention of Vienna has decided upon the following: 
 
 The tests of neat cement (Portland cement and slag cement) are not 
 sufficient of themselves to give exact information concerning those 
 products. 
 
 The test pieces obtained by the use of normal sand in a proportion, 
 of 1 to 3 do not offer , it is true, a basis sufficiently certain for judging 
 of the exact value of Portland and slag cements, but they allow the 
 formation of an approximate opinion on the quality of those materials, 
 and for this reason the introduction of the 3-day test is recommended. 
 
 In this connection the convention recommends that there should be 
 employed for the manufacture of test pieces only such machines as will 
 allow the making of tension and compression specimens as nearly 
 simultaneously as possible and with the standard amount of ramming. 
 
 The standard sand employed must, of course, be pure quartz sand. 
 
 For the determination of compressive strength there should be 
 employed machines of precision. 
 
 The permanent committee remains charged with the elaboration and sub- 
 mittal of short-time tests of quality for the other hydraulic binding media, 
 special attention to be paid to chemical analysis. Consideration of the 
 needle test iy this connection (determination of the weight under ivhich a, 
 needle or a piston will penetrate to a given depth into the binding medium 
 when in the process of hardening) as well as of the influence of warm baths 
 on the acceleration of hardening will also be given. 
 
 (ft) The tests of strength of mortar from Pozzuolana (trass) should 
 be made uniformly on a mixture of 2 parts by weight of the Pozzuolana, 
 1 part of hydrate of lime in powder, 3 parts of standard sand, and 1 part 
 of water. The manipulation should be the same as for cement, notably 
 as far as the preservation for 24 hours in air in a room saturated with 
 humidity before immersion under water is concerned. For certain 
 special uses the samples may be immersed immediately after their 
 preparation. In such cases the quantity of water entering into the 
 composition of the mortar should be increased by one tenth. Observa- 
 tion of the temperature conditions is of the greatest importance for all 
 Pozzuolana mortars ; if at all possible there should be employed water at 
 a temperature of from 15 to 18 C. for the preparation and immersion 
 of the test pieces. There should be employed for the test of Pozzuolana 
 mortars only the pure lime coming from marble, since the strength of 
 the mortar depends a great deal upon the lime. 
 
 Where the managers of works of construction produce their Pozzuo- 
 lana (trass) themselves from tufa, the rock from which the samples for 
 
44 
 
 testing are to be taken will be powdered sufficiently fine to allow 75 per 
 cent of it to pass through a sieve of 900 meshes, and 50 per cent to pass 
 through a sieve of 4,900 meshes to the square centimeter, the thickness 
 of wire being as given above. 
 
 During the process of powdering coarse particles must not be thrown 
 out, but the process must be continued until the entire quantity has 
 been reduced to the requisite degree of fineness. 
 
 6. Adhesive strength. The devising of satisfactory methods of test, in 
 which will be employed as far as possible the normal German apparatus 
 for tests of tensile strength, remains referred to the permanent committee. 
 
 7. Density. This may be determined either by means of the well- 
 known mortar volumenometer or by a calculation according to StahPs 
 method. (See for a description of that method No. 14 of Mittheilungen 
 aus dem mech. tech. Lab., etc., pp. 252-270.) 
 
 8. Action of sea water on hydraulic binding media. In consequence 
 of a paper read by Professor Debray at the Berlin convention the per- 
 manent committee was instructed : 
 
 To study the action of sea water on hydraulic binding media. 
 
 When the report on this subject was submitted to the Vienna con- 
 vention opinions were found to differ, even in regard to the form of the 
 test pieces and the methods of test. The question was, therefore, once 
 more referred to the subcommittee, which was instructed to adopt its 
 own methods of test and to take into consideration also very poor mixtures 
 with fine sand. 
 
 Besides the old questions indicated herein by italic characters as 
 having been sent back to the fourth permanent committee by the con- 
 vention of Vienna, the following questions were also submitted to it: 
 
 Determination of the methods of testing materials of construction, nota- 
 bly iron, with respect to its behavior when exposed to exceptionally low 
 temperatures. 
 
 Determination of the influence of fecal matter on hydraulic binding 
 media. 
 
 Study of abnormal behavior of cements, notably concerning time of set. 
 
 Whereas the unification of methods of testing is of great technical and 
 commercial importance, not only for materials of construction in the Strictest 
 sense of the word, but also for other raw materials and manufactured prod- 
 ucts; and 
 
 Whereas it is hardly practicable to strictly define the limit of the expres- 
 sion "materials of construction;" and 
 
 Whereas several of the institutes and experts who have taken part at the 
 convention possess great experience, not only in testing materials of con- 
 struction, but also concerning technical researches on textile fabrics, paper, 
 tc., now, 
 
 Be it resolved, that the permanent committee is instructed to consider 
 whether and in what manner the future conventions can arrive at an agree- 
 ment on uniform methods of testing substances and products of technical 
 importance. 
 
 C 
 

* ctmpniet 
 
 Binder 
 Gaylord Bros.. Inc. 
 
 Stockton, Calif. 
 T. M. Reg. U.S. Pat. Off. 
 
 YC 
 
 TA4o<=> 
 
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