From Material to Structure: Unveiling the Mechanical Behavior and Performance Evolution of Asphalt Pavements under Multi-Physical Field Coupling Effects, Phase I: Material Damage and Failure Mechanisms

• Applicant: Professor Dr.-Ing. Pengfei Liu
• Subject Area: Construction Material Sciences, Chemistry, Building Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566788528

Asphalt pavements operate under complex service conditions influenced by traffic loads, oxidative aging, thermal cycles, freeze-thaw effects, and other environmental factors. These conditions gradually alter the temperature and stress states, leading to a degradation of strength and stiffness, which ultimately compromises pavement functionality and shortens its lifespan. However, current research often oversimplifies the material’s anisotropic nature and three-dimensional stress states, resulting in discrepancies in strength and stiffness measurements that impact pavement design accuracy. Fatigue and damage characterization models also vary significantly, with many failing to accurately capture the continuous accumulation of damage and the eventual failure process. Moreover, simulating real-world pavement performance remains challenging due to the complexity of multi-physical field interactions, necessitating more refined methodologies that account for these influencing factors. This project aims to establish a fundamental understanding of the mechanical behavior and long-term performance evolution of asphalt pavements under multi-physical field effects and to develop predictive models for their damage progression. To achieve this, the research is structured into two phases. Phase I focuses on material-level investigations, identifying failure mechanisms, developing a non-linear damage model, and analyzing environmental effects on asphalt mixtures. Phase II builds on these findings, expanding the research to the structural level by integrating accelerated pavement testing and finite element simulations to develop a predictive framework for long-term performance and maintenance strategies. In Phase I, strength, fatigue, and residual strength tests will be conducted under controlled loading rate, stress, stress state, temperature, and aging conditions to quantify material degradation and failure. A non-linear damage model under multi-physical field coupling will be developed to account for strength evolution and modulus decay, enabling a more realistic characterization of fatigue resistance. These findings will provide crucial insights into the performance evolution of asphalt mixtures and serve as the foundation for Phase II. The expected outcomes include improved fatigue criteria, optimized material models, and a scientifically robust basis for sustainable pavement design and maintenance strategies. By bridging material-level research with structural applications, this project contributes to the development of durable and sustainable asphalt pavements, aiming to minimize resource consumption and carbon emissions.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Alvaro Garcia-Hernandez