Which factor influences the performance of asphalt in a warmer climate?

The viscosity of the binder is a critical factor influencing the performance of asphalt, particularly in warmer climates. In such environments, the temperatures can significantly affect the rheological properties of the binder, which is the adhesive component that holds the aggregate together. As temperatures rise, the viscosity of the asphalt binder decreases, making it more fluid and less capable of withstanding deformation under loads.

When the binder is too fluid at elevated temperatures, it can lead to issues such as rutting, where the surface develops grooves or ruts due to the constant pressure from traffic. Therefore, selecting a binder with an appropriate viscosity for warmer climates is essential to ensure that the asphalt mixture retains its integrity and performance over time. Specialized binders may also be used to enhance performance under high temperature conditions, helping to mitigate the risks associated with heat.

The other factors, while important for asphalt performance in general, do not have as direct an impact on how asphalt behaves specifically in warmer climates. The size of aggregate particles and the type of aggregate can influence surface texture and strength, while layer thickness may affect overall structural capacity, but they do not primarily address the temperature sensitivity of the binder itself.