(A) study on corrosion behavior of rebar in concrete exposed to seawater under hydraulic pressure

Abstract

Corrosion of steel in reinforced concrete structures occurs because of depassivation by chloride ion diffusion. The corrosive products are expansive, causing cracking and deterioration of the concrete structures. To date, many studies on steel corrosion in concrete have been conducted in various environments. However, the existing research considering the influence of an artificial seawater immersion environment under hydraulic pressure is not sufficient. Therefore, the purpose of this study is to determine the behavior of steel corrosion in concrete with artificial seawater immersion conditions under hydraulic pressure. The corrosion behavior of rebar was analyzed through experimental and numerical analysis methods. It was found that significant levels of the rebar corrosion occurred in the artificial seawater immersion environment under hydraulic pressure from the experimental results. In the high hydraulic pressure environment, the rebar corrosion occurred faster, and the corrosion rate was high because the penetration of water and chloride ion was rapid. However, the corrosion rate decreased rapidly after reaching the maximum corrosion rate under high hydraulic pressure. In addition, the numerical study of the rebar corrosion behavior in an artificial seawater immersion environment under hydraulic pressure was performed. The numerical analysis was developed based on a 3D finite element method. The analysis was conducted to estimate the transport of corrosion agents and rebar corrosion in concrete. In addition, the feasibility of the numerical analysis was verified by comparing the numerical results with the experimental results. The results of this study can be used as basic data to understand the rebar corrosion in concrete exposed to the deep sea environment. Also, this study can be applied to the research area related to the safety maintenance and management of civil structures exposed to deep-sea environments.