水泥基材料氯离子结合性能测定方法及其适用性分析

Test methods and its applicability of chloride binding capacity in cementitious materials

该文选取文献中较多采用的显色滴定法和电位滴定法测定水泥基材料氯离子结合性能的方法,测定5种不同盐水浓度下,水胶比为0.35、矿粉掺量为50%净浆的氯离子结合能力,从测试方法、过程和结果分析两种测定方法的差异。结果表明:显色滴定法测试过程中存在两次误差累积,且根据溶液颜色判断滴定终点时存在一定主观性,最终计算得到的氯离子结合量与电位滴定法相比存在较大差异,浸泡待测粉末样品所用氯盐溶液浓度越高差异越大;显色滴定法适用于定性分析,而电位滴定法适用于定量分析。

Chloride binding capacity of cementicious materials plays a very important role in service ability of concrete structures.However,there is no unified test method.In present study,two methods i.e.,chromogenic titration method and potentiometric titration method,are adopted to determine the chloride binding capacity of cement pastes with ratio of water to bind of 0.35 and blast furnace slag powder mixture ratio of 50%.In the test,five kinds of salt solution are used.The differences of two test methods are analyzed in terms of the test process and test results.The analysis results indicate that there are the obvious differences existent in two test methods,because of the two times error accumulation and subjective judgment in titration end point according to color change of test solution in chromogenic titration method.With the increasing of salt solution used in powder samples immersion,the differences increase.The chromogenic titration method and the potentiometric titration method can be used in the qualitative analysis and quantitative analysis,respectively.