钢筋混凝土中钢筋的氯诱导腐蚀

钢筋的氯诱导腐蚀是钢筋混凝土中钢筋腐蚀的最主要的原因之一，它会引起钢筋表面钝化膜的局部破损。混凝土中氯离子来自于采用的受污染的原材料和外界环境中氯离子的渗入。测定氯离子的阀值是众多研究的主要目标之一。由于氯离子阀值受许多因素影响，目前尚无确定的阀值。因此，对受氯离子污染的混凝土来说，对氯离子的活性及钢筋的状态的监测尤其重要。许多电化学方法，例如半电池电势、直流极化电阻、电化学阻抗谱和静电脉冲技术等已经广泛应用于研究和现场监测中，实践证明这些技术也是非常有力的工具。本文对钢筋氯诱导腐蚀的现状作了详细概述。

Chloride-induced corrosion of rebar in concrete structures

One of the most important causes is the chloride-induced corrosion. It results in the localized breakdown of the passive film that initially forms on the steel as a result of the alkaline nature of the pore solution in concrete. The harmful chloride ions can be originated from the use of the contaminated mix constituents or from the ingress of chloride ions from surrounding environment. The determination of the threshold of chloride, above that the corrosion can be initiated, has been one of the main goals of investigation by a number of researchers. Unfortunately, such a value has not been established since the threshold value of chloride is influenced by several factors. Thus, as so far as the contaminated concrete is concerned, it is very important that the activity of chloride ions and the condition of the reinforcing steel are monitored. In this respect, the use of electrochemical techniques such as half-cell potential, linear polarization potential, electrochemical impedance spectroscopy, and galvanostafic pulse technique, etc. has been used widely and been proved to be powerful tools in the process of research or in-situ monitor. In this paper, the overview on the state-of-the-art of the chloride-induced corrosion will be presented detailedly.