混杂纤维混凝土以优异的性能已广泛应用于恶劣环境的道路、桥梁、机场跑道等重大工程中，这些结构在环境腐蚀介质和车辆疲劳荷载共同作用下的耐久性破坏极为严重，而目前的研究大都集中在纤维混杂效应及力学性能方面，对耐久性问题重视不够。本项目以寒冷地区混杂纤维混凝土工程为背景，以冻融破坏引起的混杂纤维混凝土性能退化为主线，考虑环境因素与疲劳荷载的共同作用，采用先进的材料微观测试、实验室模拟试验与理论分析相结合的方法，系统开展钢-聚丙烯混杂纤维混凝土冻融损伤机理与模型研究。从混杂纤维混凝土微观结构分析入手，揭示混杂纤维混凝土冻融与盐冻破坏机理及性能退化规律，分析疲劳损伤对混杂纤维混凝土冻融破坏的影响机理与规律，建立多因素共同作用下混杂纤维混凝土冻融损伤模型与寿命预测模型，实现对冻融环境混杂纤维混凝土的耐久性寿命预测。为混杂纤维混凝土在工程中的推广应用提供理论基础与技术支撑，具有重要的理论意义与实际意义。

Hybrid fiber reinforced concretes are used as tunnel lining, bridges, roads, dams and other major projects, which mostly are in relatively harsh environments, exposured to wind and rain and corrosive medium erosion and the durability is a serious problem. So far, the effect and mechanical properties of hybrid fiber was mostly studied in the engineering fields. However, their durability was insufficiently concerned. According to the characteristics of hybrid fiber reinforced concretes in the cold regions in this project, the durability damage caused by the interaction of various factors in the environment and the hybrid fiber reinforced concrete durability research in freeze-thaw environment are researched. Steel-polypropylene fiber reinforced concrete damage mechanism of freeze-thaw damage and chloride ion penetration mechanism are studied by advanced micro-test analysis methods, the combination of laboratory environment simulation and theoretical analysis from the analysis of the microscopic structure of the hybrid fiber reinforced concrete. On this basis, the interaction mechanism of chloride and fatigue load on the hybrid fiber reinforced concrete to freezing and thawing damage is further analysed. Freeze-thaw damage model and life prediction model are established. All those work provides technical support for the application of the hybrid fiber reinforced concretes in the fierce conditions.