中文摘要：

针对钢筋混凝土板双侧Cl^-侵蚀，建立其一维扩散方程，采用分离变量法进行求解，得到广义解答，通过与误差函数和数值解答进行对比，证明该解答是古典解。通过算例分析得出，双向海水侵蚀导致Cl^-扩散较快，但并未产生浓度叠加现象；混凝土板一侧表面Cl^-浓度升高与另一侧产生浓度梯度，增加扩散动力，加快Cl^-扩散：对于扩散系数不同导致的非对称扩散，Cl^-浓度梯度在扩散系数变化处发生突变，但扩散浓度连续。

英文摘要：

Concrete slab as a part of marine engineering structure should surly be suffered from chloride ions corrosion. The relevant chloride ions diffusion problem in a concrete slab immersed in seawater was solved by means of separation variable method in this paper. In comparison with the solutions obtained by error function and numerical calculation methods, we proved this generalized solution was the correct answer for the bilateral chloride ion diffusion in a concrete slab. According to calculation and analysis, we found that the bilateral diffusion would cause greater harm than one side diffusion, but concentration superposition would not occur; chloride ion diffusion rate would speed up when concentration gradient increase caused by the increasing chloride ion concentration at one side surface. A mutation of chloride ion concentration gradient might occur where diffusion coefficient changed, but the chloride ion concentration distribution kept continuous.