OA-1. OIL ASPHALT FOR CONSTRUCTION. 



The oil asphalt shall be homogeneous, free from Avater, and GeneraL 

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



It shall meet the following requirements: Physical and 



1. Specific gravity 25V25° C. (77V77° F.)_not less than 1.000 ^^^^g'^^^ P'^^P" 



2. Flash point not less than 175° C. (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 120 to 150 



5. Loss at 163° 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 70 



6. Total bitumen (soluble in carbon disulphide) not 



less than 99.5% 

 a. Organic matter insoluble not more 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 within the test 

 limits above specified. 



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

 §hall be made in accordance with the following methods : *"S. 



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 Bulle- 



tin 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 northern United States. 

 It is intended to cover satisfactory grades of oil asphalts pre- 

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



It should be applied at a temperature of from 275° F. to 350° F. 

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

 rate of from IJ to If gallons per square yard. The application 

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

 tor so designed that it will not produce ruts during application. 

 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 3-inch laboratory screen and be retained on a 1-inch lab- 

 oratory screen. The exact range in size should be governed by 

 the kind and quality of rock used. The application should be 

 followed by a sufficient amount of clean small sized broken 



55478°— 19— Bull. 691 2 



