Time-Dependent Structural Behavior of Repaired Corroded RC Columns Located in a Marine Site

The chloride corrosion of reinforcing steel in reinforced concrete (RC) structures is a significant reason for premature deterioration and failure of RC structures in aggressive environments such as Persian Gulf region. This is one of the most important sources of engineering and economic problems in developed countries. So, the repair and maintenance of RC structures exposed to corrosive environments are very important for optimizing the service life and life cycle cost of these structures.In this research, a finite element model is applied to assess the time-dependent capacity of corroded RC structures using nonlinear analysis; this includes the impact of corrosion on inelastic buckling and low-cycle fatigue degradation of reinforcements. In this analysis, the influence of a number of repair or rehabilitation methods on the performance of a corroded square RC column due to chloride-induced corrosion are investigated and compared, including concrete surface coatings used on the external surface of concrete, and shotcrete repair after the initial cracking of concrete cover. So that, to investigate the surface coating influence on the corrosion percentage of reinforcements and structural performance due to corrosion, two surface coatings as repair methods are simulated as the equivalent concrete cover thickness. The equivalent concrete cover thickness is considered on the initial concrete cover at crack initiation time that decreases the corrosion current density and corrosion percentage after this time. Moreover, the equivalent concrete cover thickness is calculated based on experimental data of chloride diffusion into concrete specimens with surface coating located in south of Iran.