中文摘要：

混凝士结构中的荷载裂缝会缩短氯离子向钢筋表面传输的路径，导致钢筋局部脱钝起锈。采用二次加载法制作了8个带有自然开裂裂缝的普通混凝土（CO）和掺加矿粉混凝土（CS）试件，在恒温、盐水浸泡条件下进行开裂混凝土中的氯盐传输试验。将硝酸银显色法和电子探针扫描技术分别应用于定位裂缝周围区域氯离子的分布范围和测定氯离子浓度。结果表明，带有自然肝裂裂缝的混凝土试件可用于非稳态氯盐传输试验；裂缝中氯离子浓度存在梯度，裂缝宽度增大浓度梯度变小；而缝宽增大会导致裂缝深度增加，因此对氯离子扩散的影响提高；混凝土中掺加矿粉有利于抑制氯离子的传输，对提高混凝土结构服役寿命有利。研究成果可为建立更加准确的开裂混凝土氯离子传输模型提供参考。

英文摘要：

Cracks existed in reinforced concrete structure under loading will shorten the chloride diffusion path, which will cause steal corrosion in the concrete crack zone.ln present study,8 specimens of ordinary concrete （CO）and granulated blast furnace slag mixed concrete （CS）with natural crack were prepared, and the crack in the specimen was produced by secondary loading method. The chloride diffusion test was conducted in the constant temperature and salt water immersing condition. Chloride ions distribution range and chloride concentration was determined by silver nitrate chromogenic method and scanning electron probe analysis ,respectively.The test results in- dicated that specimens with natural load crack can be used to non - steady chloride transport test.Chloride concentration gradient appears in the crack surface, in which the gradient decreased with crack width increasing. Crack depth is affected by the crack width, so, the chloride diffusion depth is correspondingly affected by the crack width.Granulated blast furnace slag mixed in concrete is beneficial for chloride diffusion resistance ability and improving the concrete structure service performance.The research results can he a reference to establish a accurate chloride diffusion model.