SPECIFICATIONS FOR PLAIN AND REINFORCED CONCRETE AND STEEL 



REINFORCEMENT.* 



CONCRETE MATERIALS. 



1. Cement. The cement shall be Portland and shall meet the requirements of the standard 

 specifications. 



2. Fine Aggregates. Fine aggregate shall consist of sand, crushed stone or gravel screenings, 

 graded from fine to coarse, and passing when dry a screen having I in. diameter holes; it shall 

 preferably be of hard siliceous material, clean, free from dust, soft particles, vegetable loam or 

 other deleterious matter, and not more than 6 per cent shall pass a sieve having 100 meshes per 

 linear inch. 



3. The fine aggregate shall be of such quality that mortar composed of one part Portland 

 cement and three parts fine aggregate by weight when made into briquettes shall show a tensile 

 strength at least equal to the strength of I : 3 mortar of the same consistency made with same 

 cement and standard Ottawa sand.f 



4. Coarse Aggregates. Coarse aggregate shall consist of material such as crushed stone or 

 gravel which is retained on a screen having j in. diameter holes and having gradation of sizes from 

 the smallest to the largest particles; it shall be clean, hard, durable and free from all deleterious 

 matter. Aggregates containing dust, soft or elongated particles shall not be used. 



5. Water. The water used in mixing concrete shall be free from oil, acid, and injurious 

 amounts of alkalies or vegetable matter. 



STEEL REINFORCEMENT. 



6. Manufacture. Steel shall be made by the open-hearth process. Rerolled material will 

 not be accepted. 



7. Plates and shapes used for reinforcement shall be of structural steel only. Bars and 

 wire may be of structural steel or high carbon steel. 



8. Schedule of Requirements. The chemical and physical properties shall conform to the 

 following limits: 



9. Yield Point. The yield point for bars and wire, as indicated by the drop of the beam, 

 shall be not less than 60 per cent of the ultimate tensile strength. 



10. Allowable Variations. If the ultimate strength varies more than 4,000 Ib. for structural 

 steel or 6,000 Ib. for high carbon steel, a retest shall be made on the same gage, which, to be ac- 

 ceptable, shall be within 5,000 Ib. for structural steel, or 8,000 Ib. for high carbon steel, of the 

 desired ultimate. 



* Adopted by the American Railway Engineering Association. 



t This sand may be obtained from the Ottawa Silica Company at a cost of 2 cts. per Ib. 

 f. o. b. cars, Ottawa, 111. 

 J See paragraph 15. 



"d = 4/" signifies "around a pin whose diameter is four times the thickness of the specimen." 



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