Bitumen penetration grade 60/70 is semi hard penetration grade bitumen using as paving grade bitumen suitable for road construction and repair also for the production of asphalt pavements with below technical specification. This grade of bitumen is mainly used in the manufacture of hot mix asphalt for bases and wearing courses. Bitumen 60/70 is most used bitumen grade and basic material for all other bituminous products.
What is bitumen 60/70?
Bitumen 60/70 has the highest-boiling point, heaviest and most polar fraction from the vacuum distillation of crude oil. Bitumen 60 70 is composed of asphaltene and maltene. The heavy insoluble asphaltene molecules give bitumen 60/70 its body and softening point while the maltenes are oily and make asphalt flexible. Asphaltene molecules are soluble in aromatic solvents like toluene but insoluble in heptane. The maltenes are heptane-soluble molecules and less aromatic.
Softening point and penetration of bitumen 60/70
Penetration grade bitumen is pure petroleum grade bitumen, manufactured from vacuum bottom by passing hot air. The bitumen is produced from remain of crude oil after cracking and removing hydrocarbon. Penetration grade bitumen 60/70 has penetration between 60~70 desi-millimeter and softening point between 48 ~ 52C. The penetration grade bitumen 60/70 has a thermoplastic property which is like as synthetic resin material which gets softer with heating and hardens when cooled. This grade of bitumen 60/70 has very strong viscosity compare to other grades.