中文摘要：

分析了混凝土试件在弯曲荷载作用下各部位的应力大小和受力状态,并研究了腐蚀介质SO4^2-、Cl^-在混凝土试件中的分布规律.结果表明：在扩散距离相同的混凝土层中,纯弯区部位的SO4^2-、Cl^-含量大于弯剪区;拉应力层中的离子含量大于压应力层;弯曲荷载下混凝土试件受应力破坏最严重的部位为纯弯区拉应力层,该层中SO4^2-、Cl^-含量最大;荷载作用下,不仅渗透进入混凝土中的SO4^2-、Cl^-的量增加,离子的分布规律也发生改变,离子含量由对称分布改变为从压应力表层至拉应力表层呈＂√＂型分布,至压应力第3层或第4层（中性层）下降至最低,在拉应力表层离子含量最大.

英文摘要：

The stress magnitude and state in different part of concrete specimen under flexural load were analyzed,and the distribution regularity of corrosive media SO4^2-and Cl^-in concrete was also investigated.The results show that（1） in the concrete layers with the same diffusion distance,SO4^2-and Cl^-contents in pure bending area are higher than those in flexural shear area;（2） SO4^2- and Cl^-contents in tensile stress layer are higher than that in compressive stress layer;（3） the most severely-damaged part of concrete specimen under flexural load locates at the tensile stress layer of pure bending area,with the corresponding SO4^2- and Cl^-contents achieving the maximum;（4） the loading not only enhances the permeability but also changes the distribution regularity of SO4^2-and Cl^-in concrete.Specifically,the ion content distribution,which is different from the symmetrical style in concrete without loading,presents a √-shaped style from the compressive stress surface layer to the tensile stress surface layer,with the bottom appearing in the third layer or the fourth middle layer and the top occurring in the tensile stress surface layer.