For which purpose is the asphalt binder primarily used in a mix design?

The primary function of asphalt binder in a mix design is to bind aggregate particles together. This binding action is crucial because it ensures the stability and structural integrity of the asphalt mixture. The asphalt binder acts as the glue that holds the aggregates in place, creating a cohesive mass that can withstand traffic loads, weather variations, and other stresses encountered in the pavement.

While asphalt binder does contribute to the durability of the pavement, its foundational role is centered around the binding of the aggregates. The effectiveness of the binder in this regard influences the overall performance of the asphalt mixture, affecting its resistance to deformation, fatigue, and cracking.

Other options do not accurately capture the primary role of asphalt binder. Although they may refer to some secondary benefits or characteristics, they do not address the central purpose of binding.