Cutback Bitumen is obtained by dissolving pure bitumen in different solvents or oils. After cutback bitumen is applied, the used solvent evaporates and the bitumen remains. The type and quality of cutback bitumen depends on the quality of the base bitumen and the type and amount of solvent. The more the used solvent in the bitumen, the lower its viscosity.
cutback bitumen is commonly used as tack coats and prime coat. The following are some of the reasons for using this type of bitumen:
– Lack of access to bitumen heating equipment
– Decomposition of bitumen at high temperatures
– Bitumen cooling during implementation
– Inability to penetrate bitumen in porous minerals
– The need for worker safety
– and reduction of implementation time
Depending on the type of the used solvent in bitumen, they are classified into three categories:
– Rapid Curing (RC): It is obtained by dissolving base bitumen in high volatility solvents such as gasoline and bitumen will remain by rapid evaporation of gasoline.
– Medium Curing (MC): It is obtained by dissolving base bitumen in lighter hydrocarbons such as kerosene which has lower evaporation rate than gasoline.
– Slow Curing (SC): It is obtained by dissolving pure bitumen in slow curing oils and solvents such as gas oil. It takes a longer time for fully curing after use.