What does cracking in asphalt pavement typically indicate?

Cracking in asphalt pavement is an indicator of pavement aging, which is a natural process that occurs over time due to exposure to various environmental factors such as sunlight, temperature changes, and moisture. As asphalt ages, it undergoes oxidative hardening and becomes more brittle, making it more susceptible to cracking. This can happen even in the absence of significant external stresses, as the material itself deteriorates.

Over time, the repeated loading from traffic and the effects of weather can exacerbate these conditions, leading to more pronounced cracks in the pavement. Thus, recognizing cracking as a sign of aging is critical for maintenance and rehabilitation strategies, as it allows for timely interventions that can prolong the lifespan of the pavement before more severe failures occur.

While excessive moisture content, failure of the surface layer, and under-compaction can also contribute to pavement distress, they are not as directly related to the inherent aging process of asphalt, which is characterized by the decline in material properties over time.