中文摘要：

针对现有混凝土氯离子扩散理论模型的不足，提出了混凝土氯离子扩散系数预测的两步解析法．将混凝土看成一种是由骨料、水泥石基体和界面组成的三相复合材料，基于非均匀界面模型，估算出水泥石基体和界面的水灰比、水化度和氯离子扩散系数，然后根据微分有效介质方法，提出了混凝土氯离子扩散系数的简单解析解．做了一组混凝土氯离子扩散试验，通过与试验结果比较初步证实了所提出的两步解析法的有效性．最后通过敏感性分析量化了影响混凝土氯离子扩散系数的两个主要因素，结果表明：随着水灰比增大或骨料体积分数减小，混凝土氯离子扩散系数增大．

英文摘要：

In view of the defects in existing theoretical models for the diffusion of chloride ions in concrete, a two-step analytical method is presented in this paper for the chloride diffusivity of concrete. Concrete is considered to be a three-phase composite material, composed of aggregates, bulk cement paste, and interracial transition zone （ITZ）. Based on an inhomogeneous ITZ model, the water/cement ratios, degrees of hydration, and chloride diffusivities of bulk cement paste and ITZ are estimated. According to the differential effective medium approach, an simple analytical solution for the the chloride diffusivity of concrete is then derived. A diffusion test of concrete was conducted. The validity of the developed two-step analytical method is verified in comparison with the experimental results. Finally, two main factors that affect the chloride diffusivity of concrete are quantified through a sensitivity analysis. The results show that the chloride diffusivity of concrete increases as the water/ cement ratio increases or the aggregate volume fraction decreases.