Two-Dimensional Stress Analysis of Low-Temperature Cracking in Asphalt Overlay/Substrate Systems

Low-temperature cracking of an asphalt pavement is caused by the deformation mismatch between the asphalt overlay layer and the underlying pavement layer in cold climates or where rapid temperature change exists. When longitudinal tensile stress in the overlay reaches a certain level, transverse cracks will initiate at the surface to release the energy stored in the asphalt material. When crack spacing reduces to a certain value, crack density becomes saturated and no new cracks will form. The fracture behavior significantly changes with the properties of the underlying layer and the interface. A recently developed theory of stress transfer is used to obtain a closed-form solution for the elastic field in an asphalt overlay fully bonded to the underlying layer, based on the periodic boundary-value problem. Using the correspondence principle, the formulation is extended to consider the viscoelastic material behavior of asphalt materials, so that the timedependent material behavior of asphalt pavements under climate change can be analyzed. The modeling results compare well with finiteelement results. The analytical solution can be used in the simulation of low-temperature cracking of asphalt pavements under extreme temperature conditions.