What is the primary effect of air voids on asphalt?

The primary effect of air voids on asphalt is that they affect the thickness of the asphalt mix. Air voids are intentional spaces within the asphalt that are crucial for the overall performance and longevity of the pavement. By incorporating air voids, the asphalt concrete is allowed to expand and contract with temperature changes, which helps prevent cracking and structural failure over time.

In terms of thickness, the presence of air voids means that not all the volume of the asphalt is occupied by the asphalt binder and aggregates, which specifically influences how the final thickness is measured and maintained in the pavement structure. The appropriate balance of air voids is essential for achieving the desired density and performance characteristics of the asphalt.

Understanding this concept is critical for public works managers, as it relates directly to the quality and service life of paved surfaces, influencing maintenance practices and paving strategies.