What is the primary cause of thermal cracking in asphalt pavement?

The primary cause of thermal cracking in asphalt pavement is contraction during cold weather. As temperatures drop, asphalt materials contract. This contraction creates tension within the pavement. If the asphalt mixture has not been designed to accommodate these stress changes, the result can be visible cracks in the surface. Thermal cracking is particularly common in regions with significant temperature fluctuations between seasons. Additionally, if the asphalt binder used in the mix is too stiff at low temperatures or the aggregate has a poor interlock, it can exacerbate the risk of cracking. Understanding this phenomenon is crucial for proper pavement design and maintenance, as preventing severe thermal cracking can extend the service life of the pavement.