What role does asphalt cement serve when heated?

Asphalt cement, when heated, serves primarily as a lubricant during the paving process. This heating reduces its viscosity, allowing it to flow and easily coat aggregate materials. This property is crucial as it facilitates better workability and ensures a more uniform mixture as the asphalt bonds the aggregate together. The lubricating effect also aids in the application and compaction of the asphalt mixture, leading to a smoother surface once the paving is completed.

The role of asphalt cement extends beyond just being a binder; while it does act as a binder when cooled, during heating, its lubricating properties are most beneficial for application. It does not form a solid block when heated; rather, it becomes more fluidic, allowing for easier manipulation. Lastly, asphalt cement does not evaporate quickly; it is designed to maintain its properties under specific temperatures and conditions throughout the paving process.