不同因素对混凝土中氯离子纯扩散作用的影响

Influence of different factors on the pure diffusion of chloride ions in concrete

为了改善混凝土的耐久性,研究不同因素对混凝土内部氯离子纯扩散作用的影响,系统评估了不同内部湿度、水灰比、腐蚀离子及腐蚀时间条件下试件内部氯离子的分布情况。结果表明:随着混凝土内相对湿度增加,纯扩散作用增强,当内部湿度达到100%时试件内的氯离子扩散量及侵蚀距离最大。水灰比越大,扩散作用越剧烈,基体内氯离子的浓度越高,侵蚀深度越大。此外,硫酸根离子能够降低氯离子在混凝土中的扩散性能;混凝土内氯离子含量随着腐蚀时间的增加而增多。

In order to improve the durability of concrete and study the influence of different factors on the pure diffusion of chloride ion in concrete,it systematically evaluated the distribution of chloride ion in specimens under different conditions of internal humidity,water-cement ratio,corrosion ions and corrosion time.The results show that,with the increase of internal relative humidity in concrete,the effect of pure diffusion increases.When the internal humidity reaches 100%,the diffusion volume and ingress distance of chloride ions in the specimen are the largest.Moreover,the larger the water-cement ratio,the more intense the diffusion effect,the higher the chloride ion concentration in the matrix,and the greater the erosion depth.In addition,sulfate ions can reduce the diffusion performance of chloride ions in concrete.And the chloride content of concrete increases with the increase of corrosion time.