Cutback Bitumen (Liquid Bitumen) is Bitumen that is dissolved in a solvent . Typical solvents include Naptha, gasoline and kerosene, white spirit etc. The type of solvent controls the curing time while the amount determines the viscosity of the Cutback Bitumen.
The advantage Cutbacks have over Emulsions is a much higher residual Bitumen percent, typically over 80% compares with over 40-65% for Bitumen Emulsions. The result is more Bitumen left on the roadway after curing, for the same volume of binder applied.