Change of electrochemical property of reinforced concrete after electrochemical chloride extraction

Abstract

The half cell potential (HCP) and corrosion current of reinforced concrete specimens doped with sodium chloride were determined after electrochemical chloride extraction (ECE). The experimental results show that when ECE treatment is removed, HCP becomes more negative and corrosion current becomes larger in comparison to those before ECE treatment, then HCP shifts positively and corrosion current decreases with time. After 30 days ECE treatment, the HCP of cored specimens turn to about −100 mV due to the existence of sufficient oxygen around the exposed steel bars, but for un-cored specimens, longer time, about two months, is to be taken. The non-homogeneous HCP distribution at different layers of the same specimen after ECE treatment might induce secondary corrosion of steels.

Keywords

reinforced concrete / corrosion / electrochemical chloride extraction / half-cell potential / corrosion current

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