中文摘要：

在氯盐腐蚀及海洋环境下，钢筋混凝土结构耐久性研究的重点是确定氯离子在混凝土内部的扩散和积聚规律。在考虑混凝土材料龄期衰减系数和初始龄期等因素的基础上，提出了混凝土中氯离子二维扩散分析模型及其解析解，进而针对氯离子扩散系数具有时间和初始龄期依赖性的Fick第二定律的二维计算模型，建立了相应的二维有限元法数值分析格式，并讨论了混凝土龄期衰减系数、初始龄期及其扩散系数的时变性等因素对氯离子在混凝土中扩散和积聚规律的影响。

英文摘要：

The durability of reinforced concrete structure in marine environment is mainly focused on determining chloride diffusion in concrete.The analytical solution of Fick＇s Second Law for two-dimensional chloride diffusion model based on the diffusion coefficient attenuating with time ,varying with its initial ages is presented.Based on this analytical model,the two-dimensional finite element method is proposed for application of two-dimensional chloride diffusion in real concrete engineering. The ways by which the coefficients of attenuation age and initial age affect the chloride diffusion in concrete are discussed in detail.