What role does moisture play in asphalt pavement performance?

Moisture plays a critical role in asphalt pavement performance, primarily because it can lead to accelerated deterioration and structural issues. When moisture infiltrates the pavement structure, it can weaken the bond between the asphalt binder and the aggregate. This bond degradation may result in various forms of distress, such as stripping, which compromises the integrity of the pavement and can lead to potholes, ruts, and surface cracking.

When water becomes trapped within the asphalt or underlying layers, it can cause the pavement layers to lose strength, leading to issues like deformation and instability. Additionally, repeated freeze-thaw cycles in colder climates can exacerbate these problems by causing further cracking and damage. Understanding and managing moisture is, therefore, crucial for the longevity and durability of asphalt pavements.

The other options present aspects of pavement performance but do not accurately reflect the primary impact of moisture. While moisture is important for compaction, it doesn’t act as a binder, nor does it contribute visually; instead, it primarily poses challenges that can impair overall pavement performance.