How does aging of asphalt impact its performance?

Aging of asphalt significantly affects its performance, primarily leading to cracking and reduced flexibility. As asphalt ages due to exposure to environmental factors such as temperature fluctuations, ultraviolet (UV) radiation, and oxidization, its chemical composition undergoes changes. These changes result in the hardening of the asphalt binder, reducing its ability to flex and bend under stress.

The loss of flexibility is critical because asphalt surfaces are required to withstand loads and movements without cracking. The formation of cracks not only compromises the integrity of the pavement but also leads to increased maintenance costs and reduced service life. This process can produce more brittle asphalt, which can further exacerbate the onset of damage during freeze-thaw cycles or heavy loading situations.

Understanding this aspect is crucial for engineers and practitioners as they evaluate the longevity and performance of asphalt pavements. Proper selection of materials and additives to mitigate aging effects can significantly enhance the overall durability of asphalt mixtures.