【摘要】 实验室和工程现场经常用硝酸银显色法检测混凝土中氯离子的迁移。有3种硝酸银显色法,即AgNO3+K2CrO4法、AgNO3+荧光素法以及AgNO3法,其中AgNO3法使用最广泛,因为AgNO3法测试结果和其他两种方法相似却比其他两种方法容易操作。硝酸银显色法测量的变色边界氯离子浓度在很大范围内变化,很多因素诸如混凝土碱度、硝酸银浓度、取样方法以及混凝土中氯离子分析方法等均会对变色边界氯离子浓度测试结果产生影响。采用硝酸银显色法测试的自由氯离子渗透深度以及通过变色边界自由氯离子浓度计算的表观扩散系数可以简单、快速地评价混凝土抗氯离子渗透性。更多还原

【Abstract】 The AgNO3 colorimetric method is often used to measure the chloride penetration depth in the laboratory and the field due to its fast and easy operation. There are three AgNO3 colorimetric methods, the AgNO3+K2CrO4 method, the AgNO3+fluoresceine method and the AgNO3 alone method. Among the three methods, the AgNO3 alone method is the most widely used because it has the same accuracy but is much simpler to use than the other two. Reported chloride ion concentrations at the color change boundary vary in a very broad range because of many factors, such as sampling, chloride analysis method, alkalinity of concrete and AgNO3 concentration, could affect the testing results. Based on the measured free chloride penetration depth and free concentration at the color change boundary using an AgNO3 colorimetric method, chloride diffusion coefficient can be obtained to evaluate resistance of concrete to chloride simply and rapidly.更多还原