Framework to Predict Asphalt Pavement Aging and Its Effect on Pavement Remaining Fatigue Life

This paper aims to develop a modeling-based framework to predict asphalt pavement field aging and its effect on the pavement remaining fatigue life. It is one of the few attempts to systematically model pavement aging and investigate the pavement’s mechanical response and fatigue life evolution with aging considerations. Two road sections in Europe were selected to develop and validate the models. First, the pavement aging model was developed based on three physical processes (heat transfer, oxygen diffusion, and oxidative reaction) of pavement field aging. The model was validated using the field measurements of pavement temperature and aging product. An energy-based viscoelastic-continuum damage material model was then developed and validated through laboratory cyclic fatigue tests. After that, the coupled field aging and viscoelastic-continuum damage pavement model were developed by coupling the two models with the time-temperature-aging shift model. The pavement model was then validated with the falling weight deflectometer measurements at different pavement service years. Finally, the remaining fatigue life predictions with and without aging considerations were conducted based on the integrated model. Results indicate that the proposed model can effectively obtain the temporal evolution and spatial distribution of pavement temperature and aging gradients. The aging-induced modulus gradient causes the localization of high von Mises stress near the road surface, which demonstrates that aging is highly associated with pavement top-down and surface cracking. Based on the case study, field aging would shorten the pavement’s remaining fatigue life by up to 1.6 years when considering only the effects of aging gradient.