At what temperatures does asphalt binder typically change from solid to liquid?

The correct answer is high temperatures because asphalt binder is known to undergo a phase change from solid to liquid primarily when exposed to elevated temperatures. Asphalt is a viscoelastic material, meaning its properties can vary with temperature. At lower temperatures, asphalt binder is typically in a solid or semi-solid state, which is too viscous to be manipulated easily. As the temperature increases, the binder softens, allowing it to flow more readily, making it easier for application during road construction or maintenance processes. This property is essential for ensuring the binder can adequately coat aggregate materials and achieve the desired performance in pavement applications. Understanding this temperature behavior is crucial for engineers and construction personnel when working with asphalt to ensure proper handling and application.