Influence of surface treatment after applying electrochemical repair method on protection effect against steel corrosion in concrete

Abstract

Realkalisation and desalination are electrochemical repair methods for reinforced concrete structures damaged by carbonation and chloride attack respectively. After completing realkalisation and desalination, surface protection method could be applied for sustaining the repair effect of electrochemical repair methods for a long time. However, past papers reported that the surface coating materials are sometimes deteriorated at an early stage due to the highly alkaline atmosphere of concrete after the application of the electrochemical repair method. In this research, the performance of surface treatment materials applied to the concrete after realkalisation or desalination was investigated. Furthermore, the protection effect of the surface treatment against steel corrosion after realkalisation and desalination under the condition of accelerated carbonation or chloride attack was estimated by measuring electrochemical steel corrosion indexes. As a result, the bond strength of polymer-cement mortar (PCM) or epoxy resin on concrete applied realkalisation maintained the sound level through the accelerated carbonation for 2 years. Moreover, the re-passivation of the steel in concrete after desalination occurred more quickly in the cases of silane-based impregnation than in the cases of PCM or epoxy resin.