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Penetration Bitumen

The penetration grade bitumen is refinery bitumen that is manufactured at different viscosities. The penetration test is carried out to characterize the bitumen, based on the hardness. Thus, it has the name penetration bitumen. The penetration bitumen grades range from 15 to 450 for road bitumen. But the most commonly used range is 25 to 200. This is acquired by controlling the test carried out i.e. the distillation process. The partial control of fluxing the residual bitumen with the oils can help in bringing the required hardness. Penetration Grades are usually used in road construction and for the production of asphalt pavements with superior properties, and it's very important once it bounds the aggregates and creates a unique cohesion and stability to the bituminous mix. This grade of Bitumen is mainly used in the manufacture of hot mix asphalt for bases and wearing courses.

The penetration grade bitumen has thermoplastic property which causes the material to soften at high temperatures and to harden at lower temperatures. This unique temperature/viscosity relationship is important when determining the performance parameters such as the adhesion and application temperatures of bitumen. Penetration grade bitumen forms the basis of other road binders such as cutbacks, emulsions, and polymer-modified binders. Soft bitumen has high penetration numbers and hard bitumen has low penetration numbers.  Bitumen with high penetration grades are proper for cold regions. While, bitumen with low penetration grades are used in hot weather condition. ASTM and EN are common test methods to obtained penetration grade bitumen`s specification.