Investigation of rutting deformation mechanisms and high-temperature deformation resistance of asphalt mixtures

Rutting is a major form of high-temperature distress in asphalt pavements, significantly affecting service performance and driving safety. To investigate the evolution mechanism of rutting under coupled temperature and loading conditions, a laboratory rutting test incorporating embedded strain sensors was developed to continuously monitor internal strain responses. A transverse–longitudinal analysis method was proposed to characterize flow deformation, revealing that transverse unrecoverable deformation dominates the rutting process. The rutting evolution behavior was quantified using deformation rate, inflection point, and strain accumulation characteristics. Results show that the deformation rate exhibits an exponential decay trend with loading time, and rutting development can be divided into compaction and stable flow stages. Higher temperature, load, and hydrothermal coupling conditions significantly accelerate deformation, while larger aggregate sizes improve rutting resistance. Based on these findings, an evaluation framework integrating compaction resistance and flow resistance was established. The proposed method provides new insights into the internal deformation mechanism of asphalt mixtures and offers theoretical support for the design of rutting-resistant pavements.