Quantitative Comparison of Energy Methods to Characterize Fatigue in Asphalt Materials

Different methods have been developed to assess fatigue cracking of asphalt mixtures based on dissipated energy. Most of these methods have been motivated by the need to develop a unified fatigue criterion that is independent of the mode of loading. This paper offers critical analyses of the energy methods based on their theoretical ability to: (1) unify the results from controlled-strain and controlled-stress modes of testing for the same material; and (2) accurately assess the fatigue cracking life of different materials. The efficacy of these methods is quantitatively compared using a common set of fatigue test data. The fatigue test data were obtained using the dynamic mechanical testing of three different mixtures that have been shown to exhibit different fatigue cracking resistance in the field.