水泥基胶凝材料氯离子扩散性的研究

Study on diffusibility of chlorine ions in cement-based cementitious materials

借助X射线衍射(XRD)、扫描电镜(SEM)、水银压汞法等测试技术,从水泥熟料矿物组成、石膏种类及掺量、混合材掺量以及混合材优化匹配、粒度分布等几方面分析水泥砂浆氯离子扩散能力,并结合28d水化产物、水泥石孔隙特征等微观结构分析,探讨影响水泥氯离子扩散性的主要因素及其机理。研究表明,>100nm孔总量与总孔隙率比值(硬化水泥石有害大孔相对含量)与水泥氯离子扩散系数有较好相关性,是影响氯离子扩散系数的最主要因素。同时提出用水泥组成特征参数(T0)表征水泥氯离子扩散性的新观点。

By means of the testing technologies such as XRD, SEM, mercury intrusion method, the diffusibility of chlorine ions in cement mortar was analyzed in terms of clinker mineral composition, content and types of gypsum, content of admixture, optimization matching of admixture and particle size distribution, the main factors and mechanism that influenced the diffusibility of chlorine ions in cement mortar were also analyzed combined with microstructure analysis of 28d hydration product and pore feather of dehydrated cement paste. The results showed that the ratio of the porosity larger than 100nm to total porosity had a good relativity with diffusion coefficient of chlorine ions in cement, and it was a main influence factor. The new point of view was presented that cement composition feature parameter （To） could be used to represented diffusibility of chlorine ions in cement.