OA-2. OIL ASPHALT FOR CONSTRUCTION. 



The oil asphalt shall be homogeneous, free from water, and General. 

 shall not foam when heated to 175° C. (347° F.) 



It shall meet the following requirements : Physical and 



1. Specific gravity 25°/25° C. (77V77° F. ) __not less than 1.000 ertTsr^ ^^''^' 



2. Flash point not less than 175° 0. (347° F.) 



3. Melting point 35° C. (95° F.) to 55° C. (131° F.) 



4. Penetration at 25° C. (77° F.), 100 g., 5 sec 90 to 120 



5. Loss at 168° C. (325° F.) 5 hours not more than 1.0% 



a. Penetration of residue at 25° C. (77° F.), 100 g., 5 

 sec not less than 60 



6. Total bitumen (soluble in carbon disulphide), 



not less than 99.5% 

 a. Organic matter insoluble not less than 0.2% 



Note. — Material for any one contract shall not vary more than 0.020 

 in specific gravity nor more than 10° C. in melting point vs^ithin the test 

 limits above specified. 



Tests of the physical and chemical properties of the oil asphalt Methods of test- 

 shall be made in accordance with the following methods : *°^' 



1. Specific gravity, U. S. Department of Agriculture Bulletin 



314, p. 5. 



2. Flash point (open cup), U. S. Department of Agriculture 



Bulletin 314, p. 17. 



3. Melting point, A. S. T. M. Tentative Standard D 36-16 T. 



Proceedings A. S. T. M. 1916, p. 549. 



4. Penetration, A. S. T. M. Standard Test D 5-16. 



5. Volatilization test, U. S. Department of Agriculture Bulletin 



314, p. 19, using 50-gram sample. 



6. Total bitumen, U. S. Department of Agriculture Bulletin 314, 



p. 25. 



This specification provides for a material to be used in the con- 

 struction of bituminous macadam in the middle belt of the United 

 States. It is intended to cover satisfactory grades of oil asphalts 

 prepared from Mexican, California, Texas, and other petroleums. 



It should be applied at a temperature of from 300° F. to 350° 

 F. to the upper or wearing course of compacted broken stone at 

 the rate of from li to If gallons per square yard. The applica- 

 tion may be made by means of pouring pots or by a pressure dis- 

 tributor so designed that it will not produce ruts during applica- 

 tion. The above quantities are based on a wearing course 3 inches 

 in thickness before rolling, composed of a product which will pass 

 a 2 to 8 inch laboratory screen and be retained on a 1-inch 

 laboratory screen. The exact range in size should be governed 



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