Causes of Asphalt Cracking

UV rays from the sun can cause damage to asphalt pavements in a similar way to sunburn on skin. This occurs through a process known as oxidation, where the UV rays slowly harden the asphalt, making it more brittle over time. As the asphalt becomes more brittle, it is more likely to crack under the pressure of traffic or with changing weather conditions.

Seasonal changes from fall to winter can lead to significant temperature fluctuations. When temperatures drop rapidly from warm to cold, asphalt contracts too quickly, resulting in thermal cracks. Pavements are more prone to thermal cracking when temperature swings are frequent. Additionally, transitioning from winter to spring brings another challenge. As snow, frost, and ice melt, water can get trapped between the pavement and the still-frozen ground beneath. This saturation weakens the pavement's aggregate base and subgrade soil, increasing their vulnerability to cracking under traffic loads.

Traffic loadings put stress on asphalt pavements, which have some flexibility to bend slightly when vehicles pass over them. Each time the pavement flexes, it sustains minor damage. Heavier vehicles cause more damage than lighter ones, and older asphalt is more susceptible to damage from traffic compared to newer asphalt. When the aggregate base and subgrade soils are saturated and weakened due to seasonal changes, the damage to the asphalt increases.