Rapid curing bitumen is a type of bitumen cutback that is commonly used in construction and road maintenance projects. It is known for its fast curing properties, which allows for quicker completion of projects and reduces downtime.

The bitumen cutback is created by blending bitumen with a volatile solvent or distillate. This solvent helps to reduce the viscosity of bitumen, making it easier to handle and apply. When the solvent evaporates, the bitumen hardens and provides a durable and waterproof surface.

In the case of rapid curing bitumen, the commonly used distillate is gasoline. Gasoline is a highly volatile and flammable liquid that has a low boiling point. It is derived from crude oil through a refining process and is commonly used as fuel for internal combustion engines.

Gasoline is chosen as the distillate for rapid curing bitumen due to its properties. Here's why:

1. Fast Evaporation: Gasoline has a low boiling point, which means it evaporates quickly at normal temperatures. This fast evaporation allows for the rapid curing of bitumen, reducing the waiting time for the surface to harden.

2. Low Viscosity: Gasoline has a lower viscosity compared to other distillates like diesel oil or kerosene. This low viscosity helps in achieving better blending with bitumen, resulting in a more uniform mixture.

3. Compatibility with Bitumen: Gasoline is compatible with bitumen and does not adversely affect its properties. It allows for proper mixing and maintains the desired characteristics of the bitumen, such as its waterproofing and adhesive properties.

4. Availability: Gasoline is widely available and easily accessible. It is commonly used as a fuel for automobiles, making it readily available for use in bitumen cutbacks.

Overall, gasoline is the preferred distillate for rapid curing bitumen due to its fast evaporation, low viscosity, compatibility with bitumen, and availability. It helps in achieving quick curing of bitumen and enables faster completion of construction and road maintenance projects.