What is a major concern regarding the bonding of asphalt mixtures?

The major concern regarding the bonding of asphalt mixtures involves moisture on the surface to be paved. When there is moisture present, it can significantly affect the adhesion between the asphalt and the underlying layers. Water can create a barrier that prevents the asphalt from properly bonding to the substrate, which may result in weak spots or failure in the pavement structure over time. This is particularly critical during the construction phase, as a strong bond is essential for the longevity and performance of the asphalt pavement. Ensuring a clean, dry surface prior to paving is vital to achieving optimal performance and durability of the asphalt mixture.

In comparison, exposure to extreme temperatures can influence the workability and performance of the asphalt but doesn't directly compromise the bonding process as moisture does. Likewise, while vehicle traffic can impact the asphalt after it has set, it does not affect the initial bonding of the mixture during the installation phase. Contamination from surrounding areas, such as oil or debris, is also a concern, but it generally pertains to the quality of materials rather than moisture management specifically.