Cutbacks are form by the combination of asphalt cement with solvent (kerosene oil, diesel, gasoline etc…). In cutbacks asphalt cements are mixed up with solvents due to the requirement of resultant less viscosity fluid, so that these can be used under low temperatures.
Emulsion has a property of directly application on aggregates, but cutbacks are lack of this property. Heating of cutbacks is required before application on aggregates and cutbacks are applied by spraying on the aggregates.
Working of cutbacks (Cutbacks Function)
Cutbacks works almost in the same way as emulsion works. After spraying on aggregates, solvent evaporates from the asphalt cement and only asphalt cement lefts which becomes harden and form strong bond with aggregates.
Asphalt cement contains same properties after evaporation of solvent. From this, it is clear that solvents are only used so that it can easily apply under cold weather. There is no such other function of added solvents.
Types of cutbacks
There are different types of cutbacks, types depends on the properties of solvent. Mostly there are three basic types of cutbacks. Every type is different because of separate property containing diluents.
- Rapid curing cutbacks
- Medium curing cutbacks
- Slow curing cutbacks
- Rapid curing cutbacks are produced, after the addition of light diluents in asphalt cement… light diluent is mostly gasoline.
- Medium curing cutbacks are produced: after the addition of medium property diluents in asphalt cement. Mostly kerosene is added as a medium diluent.
- In this case oil having low volatility is added in asphalt cement. Easily available diluent containing these properties is diesel.