Identifying Fatigue Behaviors of Asphalt Mixture Under Different Strain Waveforms, Temperatures and Rest Periods with Dissipated Energy Method

Fatigue behaviors in asphalt mixtures are influenced by multiple factors, including strain level, strain waveform, and temperature, as well as rest periods. This complexity makes the analysis and interpretation of fatigue data particularly challenging. Dissipated energy (DE) is effective for developing unified fatigue models that characterize asphalt mixture behavior across varying temperatures and strain levels. However, its applicability requires further validation across a broader range of loading scenarios, especially those involving diverse strain waveforms and rest periods. This research aimed to apply the dissipated energy method to analyze fatigue behaviors of asphalt mixture subjected to extended combinations of strain waveforms and temperatures, as well as rest periods. It was found that strain waveform significantly impacts DE values and the rate of DE variation in asphalt mixtures, which contributes to differences in fatigue life at varying strain waveforms. The initial DE (IDE) indicator establishes a distinct correlation with the fatigue life of the asphalt mixture, unaffected by strain waveforms or strain levels. However, this IDE-fatigue life relationship is influenced by rest periods and temperatures. Longer rest periods shift the IDE-fatigue life curve toward a higher fatigue life, indicating improved performance. Through IDE analysis, a generalized model was formulated to represent IDE-fatigue life relationships across broad strain waveforms and strain levels, as well as rest periods, facilitating fatigue life prediction under changing conditions. This research provides valuable insights into the fatigue characteristics and underlying mechanisms of asphalt mixtures from an energy perspective.