Development and evaluation of a viscoelastic boundary element method to predict asphalt pavement cracking

It has long been accepted that cracking of hot-mix asphalt (HMA) pavements is a major mode of premature failure. Many state agencies have verified that pavement cracking not only occurred from fatigue in which a crack initiates from the bottom of the asphalt layer but also in other modes such as low temperature and the most recently identified top-down cracking. Recent work at the University of Florida has led to the development of a viscoelastic fracture mechanics-based crack growth law that is capable of fully describing both initiation and propagation of cracks in asphalt mixtures. The model requires the determination of only four fundamental mixture parameters that can be obtained from less than one hour of testing using the SuperPave® Indirect Tension Test (IDT). These parameters can account for micro-damage, crack propagation, and healing for stated loading conditions, temperatures, and rest periods.; In this dissertation, the hot mix asphalt fracture mechanics-based crack growth simulator is developed. The framework of the simulator is based on the viscoelastic displacement discontinuity boundary element method. The framework components and details of crack growth mechanism are fully described. The resulting fracture simulator is shown to predict reasonably the crack propagation of coarse-graded and fine-graded mixtures in a laboratory under cyclic loading conditions. A case study of using the newly developed fracture simulator to describe how cracking damage develops in asphalt pavement is also included.