To determine the specific gravity of given sample of bitumen
Pycnometer and balance
Specific gravity of bituminous material is defined as ratio of mass of given volume of substance to the equal volume of water, temperature of both being 27°C.
The specific gravity bottle is cleaned, dried and weighed. Water is filled in it and weight of bottle along with water is taken. Bituminous material is heated to pouring temperature and poured in the bottle to its one-fourth. Sample is cooled for 30 minutes in air ans then weighed. Then water is filled in it and weight is taken. From the weights taken, the specific gravity of bitumen can be found out.
The specific gravity of pure bitumen ranges from 0.97 to 1.02. according to Indian Standard (BIS) minimum specific gravity of paving bitumen at 27°C shall be 0.99 for grades A25, A35, A45, A65, S35, S45 and S65 , 0.98 for A90 and S90 and 0.97 for A200 and S200.
Weight of empty specific gravity bottle, W1 =
Weight of bottle+bitumen, W2 =
Weight of bottle +water, W3 =
Weight of bottle + water +bitumen, W4 =
Specific Gravity of bitumen =————