Corrosion characteristics in concrete environment of hot dip galvanised steel and Zn alloy hot dip coated steel

The modern civilisation is based on steel reinforced concrete structures. Thus, the deterioration of concrete presents a threat to the infrastructure of our society and it is caused mainly by the corrosion of steel rebars. Such deterioration requires huge expenditure to maintain and recover the concrete structures. And the cracking and spilling of concrete may lead to accidents resulting in injury or death. From the viewpoint of both economics and safety, the anticorrosion characteristics of rebars should be enhanced. Hot dip galvanised rebars have been used for this purpose in Euro-American countries, while they have not been used in Japan. For the latter, high anticorrosion epoxy coated rebars have dominated the market. But due to the high cost of these, the application of less expensive hot dip galvanised steels should be investigated. The authors investigated the anticorrosion characteristics in concrete of hot dip galvanised steel and Zn alloy hot dip coated steel in this study. The electrochemical behaviours of specimens in the simulated concrete solutions were analysed by cyclic voltammetry, optical microscopy and X-ray diffraction analysis, and the corrosion characteristics of those specimens and the potential of this application were discussed.