Probabilistic Analysis of Crack Spacing in Asphalt Pavements under Thermal Loading

This paper presents a stochastic model for the prediction of tensile cracking behavior of asphalt pavements under thermal loading. The spatial variability in the stiffnesses of the asphalt material and base course is modeled using homogeneous random fields. Based on a strength-based failure criterion, the model is used to predict the probability distribution of the crack spacing of asphalt pavements subjected to a given temperature drop. Parametric studies are conducted to examine the effects of the statistical properties of the asphalt material and base course on the spacing of thermal cracks. The model is further applied to determine the maximum allowable pavement length corresponding to a target of probability of cracking. In parallel, an analytical model is developed to predict the probability of cracking for a given pavement. The analytical solution establishes a relationship between the maximum allowable pavement length and the material tensile strength for a target probability of cracking, showing excellent agreement with the result of numerical simulation. This analytical relationship offers a theoretical basis for reliability-based design of the saw-and-seal operation for asphalt pavements.