A Phenomenological Fatigue Performance Model of Asphalt Mixtures Based on Fracture Energy Density

摘要

In this study the fatigue performance of asphalt mixtures was interpreted based on fracture energy density. Recent studies indicate that the fracture energy from indirect tension tests correlates with the field performance of asphalt concrete. The fracture energy density was obtained from indirect tensile strength tests, and the fatigue performance of asphalt mixtures was evaluated with four-point bending beam fatigue tests implemented at three different strain levels. Two different asphalt mixtures with varying binder contents were tested during this study. Test results showed that the fracture energy density could be an appropriate material property in phenomenological fatigue models. Thus a phenomenological fatigue model based on fracture energy density is presented, and this approach could be advantageous because a simple fatigue model based on fracture energy density does not require time-consuming fatigue tests. For comparison purposes, the various types of fatigue models were evaluated, and fatigue models based on fracture energy density and dissipated energy showed rather high prediction accuracy. In general, fatigue models based on the energy concept have the least dependence on material properties and can predict the fatigue lives of asphalt mixtures without changing coefficients.