DISSIPATED CREEP STRAIN ENERGY AS A FATIGUE PERFORMANCE CRITERION FOR ASPHALT MIXTURES
In this study the fatigue performance of asphalt mixtures was interpreted by dissipated creep strain energy. The dissipated creep strain energy of asphalt mixtures was recently used as a criterion for separating micro and macro cracks in asphalt pavement. Micro and macro crack boundary, play a major role in healing concept of asphalt pavement. The dissipated creep strain energy obtained from indirect tensile strength test and fatigue performance of asphalt mixture were evaluated with four point bending beam fatigue tests, which were implemented at three different strain levels. Two different asphalt mixtures with varying binder content were tested during this study. Fatigue test results showed that dissipated creep strain energy is a good alternative for dynamic modulus in phenomenological fatigue models. Simple fatigue model based on dissipated creep strain energy has no need to perform time consuming fatigue test. For comparing purpose, the various types of fatigue models were evaluated and fatigue model based on dissipated creep strain energy shows rather high prediction accuracy. In general, fatigue models based on energy concept have the least dependency on material properties and they can predict the fatigue lives of asphalt mixtures without changing coefficients.