Cutback bitumen is type of bitumen cutback by adding controlled amounts of petroleum additives such as kerosene. This is done to reduce the viscosity of the bitumen temporarily so it can penetrate pavements more effectively. The materials used to cutback bitumen will evaporate after application to leave the remaining material similar in hardness to the original bitumen.
CUTBACKS are classified into three types, rapid-curing (RC), medium-curing (MC) and slow-curing (SC) depending on the solvent used. They are further defined by a number which indicates the minimum kinematic viscosity of the cutback.