Which component of an asphalt mix is considered the most important but often overlooked?

The most important yet often overlooked component of an asphalt mix is air voids. Proper control of air voids is crucial because they significantly affect the durability, strength, and permeability of the asphalt. When the air void content is too high, it can lead to an increased risk of water infiltration, which can cause stripping and other forms of damage to the pavement. Conversely, if air voids are too low, it may result in increased density and brittleness of the mix, leading to cracking under stress.

Managing air voids is essential in achieving the ideal performance characteristics of the asphalt mixture. Even though they may not always be the focus during the mixing and compaction processes, maintaining the correct air void percentage helps ensure that the pavement will perform effectively under traffic loads and environmental conditions. This aspect plays a vital role in the overall lifespan and maintenance needs of the roadway.