荷载与氯盐环境作用下混凝土结合界面耐久性能及抗剪机理研究

Concrete interface widely exists and acts as an important role in modern concrete structures. The durability and shear behavior of the concrete interface is important basic to ensure the serviceability and safety of the structures under the coupling actions of service load and chloride environment. In this proposal, multi-medium transport theory and microcosmic testing techniques will be used to reveal the coupling effect and influence mechanism of the load and chloride environment on mass transport in concrete interface. Then, both multi-phase transport model and mesoscale transport model will be established. Moreover, electrochemistry theory and moving mesh techniques will be adopted to discover the coupling mechanism and parameter quantitative relationship of the multi-physic happened in concrete interface. Thus, the coupling analysis of mass transport in the interfacial concrete, the interfacial rebar corrosion development, and the interface shear evolution will be realized. Furthermore, by adopting the direct / oblique shear test and the shear-friction theory, evolution mechanism of collaborative shear performance of concrete and interfacial rebar will be revealed, and the time-dependent constitutive models for adhesive bonding, friction and dowel action of the concrete interface will be established. Finally, the calculation method of shear capacity of concrete interface under the coupling actions of load and chloride environment will be proposed. The outcomes of this research can enrich and develop the durability theory of concrete structure, and provided the theoretical support and method guidance for the durability design and long-term safety evaluation of the concrete interface under the coupling actions of load and chloride environment.

混凝土结合界面在现代混凝土结构中广泛存在且功能重要，在荷载与氯盐环境作用下，结合界面的耐久性能和抗剪性能是保证结构正常使用和安全服役重要基础。本项目拟采用多重介质传输理论与微观测试技术，揭示荷载与氯盐环境作用对界面物质传输的耦合效应和影响机理，构建界面物质的多相传输模型和细观传输模型；利用电化学理论和移动网格技术，阐明混凝土结合界面内部多物理场的耦合作用机制和参数间定量关系，实现结合界面中物质传输-界面钢筋腐蚀发展-界面抗剪性能演变的多场耦合分析；基于直/斜剪试验研究和界面剪切摩擦理论，探明荷载与氯盐环境作用下结合界面混凝土-钢筋协同抗剪性能的演化机理，建立结合界面粘结力-摩擦力-销栓力等剪切抗力的时变本构模型，最终形成混凝土结合界面长期抗剪性能的计算方法。成果可进一步丰富和发展混凝土结构耐久性基础理论，为荷载与氯盐作用下混凝土结合界面的耐久性设计和长期安全性能评估提供理论支持和方法指导。

混凝土结合界面在现代混凝土结构中广泛存在且功能重要，在荷载与氯盐环境作用下，结合界面的耐久性能和抗剪性能是保证结构正常使用和安全服役重要基础。本项目围绕物质在混凝土结合界面多重介质内部的非均匀传输机制，混凝土结合界面内部多物理场的耦合作用机制和参数间的定量关系，以及混凝土结合界面混凝土-钢筋的多重抗剪机制及演化机理三个关键科学问题开展了研究。采用多重介质传输理论与微观测试技术，揭示了荷载与氯盐环境作用对界面物质传输的耦合效应和影响机理，构建了界面物质的多相传输模型和细观传输模型；利用电化学理论和移动网格技术，阐明了混凝土结合界面内部多物理场的耦合作用机制和参数间定量关系，实现了结合界面中物质传输-界面钢筋腐蚀发展-界面抗剪性能演变的多场耦合分析；基于直/斜剪试验研究和界面剪切摩擦理论，探明了荷载与氯盐环境作用下结合界面混凝土-钢筋协同抗剪性能的演化机理，建立了结合界面粘结力-摩擦力-销栓力等剪切抗力的时变本构模型，最终形成了混凝土结合界面长期抗剪性能的计算方法。项目研究成果进一步丰富和发展了混凝土结构耐久性基础理论，在装配式混凝土桥梁设计、输电线路的腐蚀检测等方面实现了工程应用，为荷载与氯盐作用下混凝土结合界面的耐久性设计和长期安全性能评估提供理论支持和方法指导。