Bitumen or bituminous binder we can supply are mainly of the following types:
Bitumen 80/100: The characteristics of this grade confirm to that of S 90 grade of IS-73-1992. This is the softest of all grades we supply. This is suitable for low volume roads and is still widely used in the country.
Bitumen 60/70: This grade is harder than 80/100 and can withstand higher traffic loads. The characteristics of this grade confirm to that of S 65 grade of IS-73-1992. It is presently used mainly in construction of National Highways & State Highways.
Bitumen 30/40: This is the hardest of all the grades and can withstand very heavy traffic loads. The characteristics of this grade confirm to that of S 35 grade of IS-73-1992. Bitumen 30/40 is used in specialized applications like airport runways and also in very heavy traffic volume roads in coastal cities in the country.
Industrial grade bitumen
Industrial grade bitumen is also known as blown bitumen. This is obtained by blowing air into hot bitumen at high temperatures (normally beyond 180 0C). Blowing hot air into bitumen at high temperatures results in structural changes in bitumen. Esters are formed in this process and these esters link up two different molecules and higher molecular weight material increases drastically. In the process the asphaltene content is increased which in turn results in higher softening points and very low penetration number. Industrial grade bitumen is used in industrial applications and in water proofing, tarfelting etc.
Cutback is a free flowing liquid at normal temperatures and is obtained by fluxing bitumen with suitable solvents. The viscosity of bitumen is reduced substantially by adding kerosene or any other solvent. Cutback has been used in tack coat applications.