普通混凝土中氯离子含量随龄期的变化规律研究

Study on Temporal Variation Pattern of Chloride Ion Content in General Concrete

采用复合银电极自动电位滴定法测定混凝土中水溶性氯离子含量和酸溶性氯离子总含量,研究了其28 d龄期内氯离子含量的变化情况。试验结果表明:水溶性氯离子含量随着龄期的延长而逐渐降低,到一定龄期之后趋于稳定;酸溶性氯离子总含量在较长一段时间之内波动变化,但是没有明显降低。稳定后的水溶性氯离子含量大约为酸溶性氯离子总含量的85%,且氯离子含量越低时两者差异越小,水灰比越小两者差异越大。酸溶性氯离子总含量的测定更容易且较为简单可行,并可以在较短龄期时进行准确测定,为工程质量安全提供可靠的数据。

This article adopted complex silver electrode automatic potentiometric titration to determine the content of water-soluble chloride ion and the content of total acid-soluble chloride ions in concrete,studying the variation pattern of the content of chlorine ion within 28 days of age. The results showed that along with the prolongation of age days,water-soluble chloride ion content gradually reduced;to a certain time,it tended to be stable. Total acid-soluble chloride ion content within a long period of time fluctuated,but not significantly reduced. Stability of water-soluble chloride ion content is about 85% of the total amount of acid-soluble chloride ions,and it got closer when the chloride ion content lower,the difference got larger when the water-cement ratio smaller. Determination of the total amount of acid-soluble chloride ion is easier and relatively simple and feasible. It can be determined relatively in a short age,providing reliable data for the engineering quality and safety.