基于电位滴定法测定混凝土中氯离子含量的研究

Study on the determination of chloride ion in concrete based on potentiometric titration

为解决传统Cl^(-)含量测定过程计算得到的Cl^(-)含量偏差数据点过多,导致测定结果易存在误差的问题,本研究对基于电位滴定法的混凝土中Cl^(-)含量测定方法展开研究。方法设计如下:利用Fick第二定律得到Cl^(-)的一维扩散深度,结合Cl^(-)与自由Cl^(-)之间的关系,计算得到Cl^(-)扩散的计算模型;然后,利用电位滴定法得到Cl^(-)的二次微分曲线,在此基础上处理Cl^(-)浓度分布边界元;在计算混凝土中的孔隙率后,引入Temkin吸附,完成对混凝土中Cl^(-)含量的测定。在利用该方法完成对胸墙结构混凝土中Cl^(-)含量的测定后,为进一步验证测定方法的有效性,与传统Cl^(-)含量测定方法进行性能对比,发现该方法测定过程中出现的含量偏差数据点少,使得Cl^(-)含量测量结果更加准确。

In order to solve the problem that there are too many deviation data points of chlorine ion content calculated in the traditional determination process,which makes the determination result prone to errors,this paper studies the determination method of chlorine ion content in concrete based on potentiometric titration.The method design is as follows:the one-dimensional diffusion depth of chloride ion is obtained by using Fick second law,and the calculation model of chloride ion diffusion is obtained by combining the relationship between chloride ion and free chloride ion.Then,the quadratic differential curve of chloride ion is obtained by potentiometric titration,and the boundary element of chloride ion concentration distribution is processed on this basis.After calculating the porosity of concrete,Temkin adsorption was introduced to complete the determination of chloride ion content in concrete.After the determination of chloride ion content in the concrete of parapet structure by this method,in order to further verify the effectiveness of this method,the performance comparison with the traditional chloride ion content determination method was made.It was found that there were fewer data points of content deviation in the determination process of this method,which made the measurement result of chloride ion content more accurate.