荷载与硫酸盐腐蚀耦合作用下沥青混合料疲劳损伤机理研究

盐渍土地区，沥青路面在交通荷载与硫酸盐腐蚀耦合作用下早期损坏严重，使得其服务寿命远达不到设计年限。目前，对荷载与硫酸盐腐蚀耦合作用下沥青混合料疲劳损伤的研究尚未多见，已有未考虑硫酸盐腐蚀作用的沥青混合料损伤分析与疲劳预估模型，未能真实反映沥青混合料的工作本质。本项目采用自行研制的荷载与硫酸盐腐蚀耦合作用试验装置，分析沥青混合料力学性能衰减规律，提出荷载与硫酸盐腐蚀耦合作用下沥青混合料疲劳损伤评价指标；利用物相分析技术与数值模拟，研究荷载作用下硫酸盐溶液在沥青混合料孔隙中的迁移规律及硫酸盐结晶膨胀规律；基于损伤力学理论，建立荷载与硫酸盐腐蚀耦合作用下沥青混合料疲劳损伤本构模型，数值模拟不同试验参数下沥青混合料疲劳损伤演化过程，建立沥青混合料的疲劳损伤演化方程。研究成果从损伤力学的角度揭示荷载与腐蚀耦合作用下沥青混合料的疲劳破坏行为，可为盐渍土地区沥青路面的寿命预估与结构设计提供重要理论依据。

In the area of saline soil, early damage of asphalt pavement is serious under the action of load and sulfate corrosion, so that its service life far less than the design life. At present, the research on fatigue damage mechanism of asphalt mixture subjected to load and sulfate corrosion is seldom reported. And the damage analysis and prediction model fail to reflect the nature work of asphalt mixture without considering the sulfate corrosion. The project studies the mechanical properties attenuation law of asphalt mixture and presents fatigue damage evaluation index under the load and sulfate corrosion, based on the coupling action test of load and sulfate corrosion. Using modern phase analysis technique and finite element analysis , the project studies the sulfate solution migration and sulfate crystallization expansion rule in asphalt mixture. Based on the theory of damage mechanics, fatigue damage constitutive model of asphalt mixture is established under the action of load and sulfate corrosion. Fatigue damage evolution process of asphalt mixture with different test parameters are simulated under the action of load and sulfate corrosion, and fatigue damage evolution equation of asphalt mixture is established. Research results from the damage mechanics angle reveal the fatigue failure behavior of asphalt mixture under the action of load and sulfate corrosion, and it provides the important theoretical basis for structure design and life prediction of asphalt mixture in the area of saline soil.