Fracture Performance of Asphalt Concrete under Long-Term Vapor Exposure

Long-term vapor exposure generates persistent moisture gradients across asphalt pavement sections, driving moisture diffusion into asphalt concrete (AC). Moisture in AC weakens the materials and exacerbates the action of load, causing premature distress such as cracking in pavement. However, few investigations have focused on the effects of long-term vapor exposure on AC's fracture performance. We approached this issue by simulating the fracture process of AC experiencing long-term vapor exposure under an indirect tensile load. The cohesive zone model (CZM) was introduced to depict the fracture process. We calibrated the CZM model by minimizing the difference between simulation and laboratory measurements. The results showed that long-term vapor exposure lowered the bonding strength in AC, accelerating the cracking initiation and propagation. The damage distribution showed that the interface between aggregates and mortar was more prone to damage since it bore more stress than the bulk of the asphalt mortar. This study reveals the fracture performance of AC under long-term vapor exposure, which helps develop measures to prevent premature cracking in the pavement and prolong the service life.