混凝土氯离子综合机制扩散模型及敏感性研究

A study on multi-nismic chloride diffusion and transport model and sensitivity

为了更深入了解氯离子侵蚀造成钢筋混凝土结构使用寿命缩短的原因,研究了各种因素对氯离子扩散的影响,基于Fick第二定律,推导出考虑综合影响机制的氯离子扩散理论迁移模型,确定了温度、时间以及结构劣化效应和混凝土结合作用与氯离子扩散系数的关系,并对各影响机制的内在相关性和重要性进行了敏感性分析,同时对迁移模型进行了实验和工程验证.

One of the major causes of reduction of serve life of reinforced concrete structures is chloride-induced deterioration of the structures where corrosion of the reinforcing steel occurs. The design and reinforcing of the reinforced concrete structure is mainly based on the study of influencing mechanisms of chloride diffusion and the accurate evaluation of chloride incursion. Boundary conditions and concrete properties retain changing at all time through the diffusion process of chloride ion. Based on Fick's second law of diffusion, this paper presents a theoretical multi-mechanism diffusion and transport model of chloride ion and considers the relation between chloride diffusion coefficient and mechanisms, such as time, temperature, micro-defect and binding effect of concrete. The sensitivity of inherent relativity and roles of the various mechanisms is analyzed. In addition, the application of this diffusion and transport model is verified with experimental and engineering data.