Low-temperature stresses and fracture analysis of asphalt overlays

Thermal cracking of asphalt overlays is a leading cause of pavement deterioration. The thermoelastic response of a multilayered pavement structure is modeled using a transient thermal analysis followed by a quasi-static stress analysis at discrete time intervals using finite element analysis. Numerical analysis of two- and three-dimensional cracking problems is performed. Based on a fracture mechanics approach, the potential of thermal cracks to propagate through the overlay is examined using both a displacement formula and an energy-balance principle. The interaction between multiple cracks and the effect of bond between layers on crack propagation are examined. The proposed numerical methods for analysis of pavement thermal cracking provide a means to characterize and optimize different evolving materials and innovative pavement reinforcement techniques.