Fatigue cracking is one of the major distresses in asphalt pavement. In past studies that characterized the fatigue mechanism of asphaltic materials, plasticity has been considered independent of damage. However, the plasticity of asphalt binders significantly impacts the fatigue performance and service lifetime of asphalt pavement. The primary objective of this paper is to develop a plasticity-based fatigue damage model for asphalt binders to predict complex fatigue behaviors. An innovative experimental approach was used to integrate creep tests with unidirectional cyclic tests. Perzyna’s viscoplastic model that incorporates the Drucker–Prager yield function is proposed to capture the asphalt binders’ stress state and viscoplastic response. The Kachanov–Rabotnov damage evolution law is applied to predict the viscoplastic damage evolution of asphalt binders. The proposed model is validated by extensive experimental data under various loading paths at different temperatures. The results indicate that the plasticity-based fatigue damage model exhibits robust effectiveness in capturing the viscoplastic damage evolution of asphalt binders under various loading paths. Validation results demonstrate that the viscoplastic damage strain of asphalt binders under various loading paths of cyclic loading tests can be accurately predicted based on the model determined by long-term creep test results, with correlation coefficients (R2) exceeding 0.89. This integration highlights the model’s versatility and applicability in practical scenarios, providing a reliable tool for understanding and predicting asphalt binder’s behavior under diverse loading conditions.
Wang et al. (Fri,) studied this question.