混凝土中钢筋腐蚀临界氯离子浓度的研究方法

Research Methods of Chloride Threshold Value for the Corrosion of Steel Reinforcement in Concrete

临界氯离子浓度是确定氯离子环境下钢筋混凝土结构寿命的必备参数之一,为耐久性研究中的一个重点.在综述了混凝土中钢筋腐蚀临界氯离子浓度常用的研究方法,包括失重法、半电池电位法、宏电池法、线性极化法、交流阻抗谱及其他方法,介绍了各种方法的原理、特点及应用过程中存在的问题后.得出由于各种方法判别混凝土中钢筋腐蚀的起始点,进而确定临界氯离子浓度所用的标准与原理不同,获得的临界氯离子浓度也可能并不完全一致.因此,研究方法的差异可能是致使现今临界氯离子浓度的报道值具有高离散性的一个重要原因.

The chloride threshold value(CTV) is one of crucial parameters for determining the service life of reinforced concrete structure exposed to chlorides.Accordingly,it has become an emphasis of research on the durability of reinforced concrete structure.In this paper,the research methods of CTV including mass loss,half-cell potential,macro-cell,linear polarization,electrochemical impendence spectroscopy and other electrochemical methods have been reviewed.Especially,the mechanisms,some important features and existent issues in evaluation methods are introduced.The research indicates that due to the differences of mechanism and standard of identifying the corrosion initiation,the CTVs obtained by the various research methods may be different.So,the different research methods may have contributed to the scatter of CTV reported in the pervious literatures.