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