Description of Medium Curing Cutback Bitumen
Medium Curing Cutback Bitumen is bitumen cut back with a petroleum solvent such as kerosene or naphtha to reduce its viscosity and render it more workable at ambient temperatures. It is produced to cure or set at a moderate rate as the solvent evaporates, leaving the base bitumen behind to bind aggregates or seal surfaces. This reduced viscosity bitumen is most commonly used in road construction and maintenance activities such as prime coating, tack coating, and cold mix asphalt production.
Designations like MC-30, MC-70, MC-250, MC-800, and MC-3000 indicate higher viscosity and slower curing rates, based on the project requirements and climatic conditions.
Medium Curing Cutback Bitumen represents a middle ground between Rapid Curing (RC) and Slow Curing (SC) grades and offers an operating compromise between fast-drying and longer-setting materials and can be applied across most climates and construction timescales.
Its relatively moderate rate of evaporation is adequate to offer penetration into granular surfaces to enhance adhesion and longevity. It is especially useful when one does not require the heating of pure bitumen or when early traffic return is not crucial. However, since it carries solvent, there must be safe handling, storage, and regard for the environment.
