A patch repair is performed for reinforced concrete structures deteriorated by chloride attack. However, there is possibility that in cases of repair work, the bars around the joint will corrode again with macrocell in a comparatively short time after the repair. The authors have been developing macrocell corrosion reduction method using silane surface penetrant so far. However, it is pointed out that the bond strength between the existing part and the patch repair material is reduced by water repellency of the silane surface penetrant. Therefore, this study focused on epoxy resin with a high bond strength. In this study, methods for reducing the corrosion rate were developed by increasing the electrical resistance between the existing part (anode) and the patch repair part (cathode). Also, bond strength between the existing part and the patch repair material was investigated. Therefore, the macrocell corrosion after a patch repair was evaluated and inhibition methods for macrocell corrosion were proposed. In the experiments, the potential, the macrocell and microcell corrosion currents, the electrical resistance and the bond strength were measured. As a result, the macrocell was formed between much and less chloride ions after the patch repair. This macrocell corrosion current density was reduced by a coating of epoxy resin or acryl type adhesive. Furthermore, the bond strength increases.

patch repair, epoxy resin, acryl type adhesive, macrocell corrosion, bond strength.