物理硬化对沥青材料低温性能影响机理研究

物理硬化是影响沥青材料低温性能的本源之一，但目前物理硬化对沥青材料低温性能影响机理尚不明确、沥青材料低温性能的评价体系未能考虑物理硬化的影响，由此可能导致沥青材料低温性能评价结果失效。针对上述问题，本项目将从物理硬化作用下沥青材料的微观特征演变规律入手，详细分析物理硬化作用后沥青分子弛豫模态、分子构象及微观体积特征变化规律；运用断裂力学、流变力学原理，研究物理硬化作用下沥青材料宏观力学行为特征，结合微观、宏观试验结果，阐明沥青材料微观结构变化与宏观力学行为的内在联系，并构建物理硬化作用下沥青材料温度应力本构模型；基于上述结果，提出考虑物理硬化效应的沥青材料低温性能评价指标。.本项目的研究将揭示物理硬化对沥青材料低温性能影响机理，为准确评价沥青材料低温性能提供理论依据，对于研发路面低温抗裂材料具有一定的参考意义，对于路面计算力学和材料学科的发展也有一定的推动作用。

Physical hardening is one of the fundamental causes that affect the low temperature performance of asphalt. However, the mechanism of the effect of physical hardening on asphalt low temperature performance is not clear. Additionally, the low temperature performance evaluation system has not considered the effect of physical hardening. Therefore, these issues may lead to the failure of the low temperature performance evaluation. Aiming at solving these problems mentioned above, the study will start with analyzing the evolvement rule of asphalt microscopic characteristics undergoing physical hardening, and then analyzing the variation of asphalt molecular relaxation mode, molecular conformation and microscopic volume characteristics after the physical hardening. Based on the theory of fracture mechanics and rheological mechanics, the macroscopic mechanical behavior of asphalt under the physical hardening effect will be investigated. By combining the macroscopic and microscopic experimental results, the internal relations between microstructure change and macroscopic mechanical behavior will be interpreted, and the temperature stress constitutive model of asphalt materials under the physical hardening effect will be derived. Based on the results above, a sensitive and effective asphalt low temperature performance evaluation index, considering the effect of physical hardening, will be proposed..The project will reveal the mechanism of the effect of physical hardening on low temperature performance of asphalt, providing a theoretical basis for an accurate assessment of asphalt low temperature performance. It will also have certain reference for the development of low temperature anti-cracking material for pavement and facilitate the development of pavement computational mechanics and material science.