干湿交替环境下混凝土硫酸盐侵蚀机理复杂且破坏严重，既有研究尚未合理地阐释混凝土硫酸盐侵蚀机理、损伤模式和耐久性演变历程。本项目拟基于化学热力学和动力学理论，分析侵蚀介质特性、侵蚀条件和侵蚀模式等对混凝土硫酸盐侵蚀影响，开展混凝土硫酸盐侵蚀的定性和定量分析，剖析混凝土硫酸盐侵蚀机理。探讨干湿交替环境变化引发的环境载荷和硫酸盐耦合作用下混凝土硫酸盐侵蚀过程，构筑干湿交替环境下混凝土硫酸盐侵蚀模型；优选适宜的混凝土硫酸盐侵蚀损伤评价指标，提出混凝土硫酸盐侵蚀损伤评判准则和量化方法。融合数值仿真和试验，分析混凝土硫酸盐侵蚀微裂纹生长-聚合、宏观裂纹形成-扩展-破坏全过程，推导干湿交替环境下混凝土硫酸盐侵蚀耐久性演化过程，为相应的混凝土结构耐久性评估和寿命预测提供技术支撑。

Under drying-wetting alternate environment, the degradation mechanism of concrete subjected to the sulfate attack is complex, and the corresponding concrete structures are badly damaged. However, the existing researches have not investigated the deterioration mechanism, damage mode and durability evolution of concrete under sulfate attack. Based on the theories of chemical thermodynamics and kinetics, this study will investigate the effect of erosion media, deterioration condition and damage model on the sulfate attack mechanism of concrete. Both qualitative and quantitative analysis methods for representing the deterioration process of concrete subjected to sulfate attack are proposed, and the sulfate attack mechanism of concrete is also deduced. Under the coupled effect of sulfate attack and the environmental loads generated by drying-wetting alternate environment, the degradation process and damage model are proposed. By comparing the evaluation indexes, the evaluation criteria and the quantitative approach of the sulfate attack are put forward. Numerical simulations and tests are carried out to investigate the whole processes of the micro cracks’ production and aggregation and the macro cracks’ formation and extension in concrete are also explored. In addition, the durability evolution of concrete under drying-wetting alternate environment is deduced, which provides the technical support for the durability assessment and life prediction of concrete structures.