目前有关混凝土结构耐久性设计大多是依据完整混凝土的研究，实际的混凝土结构多是带有裂缝的多相复合材料，这在一定程度上高估了混凝土结构的服役寿命。通过化学滴定法测量混凝土中自由氯离子含量，系统研究锂渣的掺量、荷载大小、裂缝宽度对自由氯离子时空分布的影响，并根据Fick第二定律计算氯离子的扩散系数。结果表明： 在硫酸盐与氯盐混合溶液中，自由氯离子含量显著降低，硫酸根离子能够有效减缓氯离子在混凝土中的传输； 掺加20%锂渣能够减小氯离子在混凝土中的传输速率； 混凝土中的氯离子传输速率随着荷载和裂缝宽度的增加而增加。

At present, the durability design of concrete structures is mostly based on the research of complete concrete, and the actual concrete structures are mostly multiphase composite materials with cracks, so the service life of concrete structures is overestimated to some extent. The content of free chloride ions in concrete is measured by chemical titration. The effects of lithium slag content, load and crack width on the distribution of free chloride ions are studied, and the diffusion coefficient of chloride ions is calculated. The results show that: (1) In the mixed solution of sulfate ions and chloride ions, the content of free chloride ions is significantly reduced, and sulfate ions can effectively slow down the transport of chloride ions in concrete; (2) The addition of 20% lithium slag can reduce the transport rate of chloride ions in concrete; (3)The transport rate of chloride ion in concrete increases with the increment of load and crack width.