Structural Performance Degradation of Corrosion-Damaged Reinforced Concrete Beams Based on Finite Element Analysis

Abstract

The impact of the seismic performance of corrosion-damaged reinforced concrete (RC) members on the overall seismic performance of the entire RC structure must be investigated. Related research results provide important guidance for a more accurate seismic performance evaluation of RC structures with corroded members including beams and columns. However, currently available technologies for the seismic evaluation of existing RC structures do not consider the impact of reinforcement corrosion-induced deterioration on the seismic performance of RC members. The main focus of this study is on proposing a practical methodology to evaluate the seismic performance of such buildings. More specifically, the proposed methodology enables a direct quantitative evaluation of seismic performance by estimating the structural performance based on the strength and deformation capacity of corroded members. In pursuit of this research background and the objectives, our research team first performed an experimental study to estimate the impact of reinforcement corrosion on the structural behavior of RC shear beams and flexural beams and determine the factors associated with structural performance deterioration. A high correlation between the half-cell potential (HCP) before and after reinforcement corrosion of RC beams and the structural performance degradation factor based on the energy absorption capacity has been seen previously. In this study, a finite element analysis (FEA) was conducted, in which bond strength loss between rebar and concrete due to reinforcement corrosion of beam members was considered as one of the aging-related degradation factors, and the correlation between structural performance degradation before and after corrosion in beam members was studied. In addition, we compared and analyzed the results of the previous experimental research and FEA conducted in this study and proposed a structural performance degradation factor as a function of corrosion of shear and flexural beams. The research results indicate that the FEA-derived bonding factor (β) and performance degradation factor (ϕ) of flexural beam can be approximated with the equation ϕ=(0.36−β)−1+101 (R2 = 0.94), together with β–mV (average potential difference in voltage) correlation mV =(1.36−β)/(0.018−0.05β). In the case of shear beams, FEA resulted in ϕ=37.3β+63, which enables regression approximation, showing a high correlation (R2 = 0.98), together with β–mV correlation (mV =932.5β−1075). Using the mV–β–ϕ correlation curves, the bonding factor (β) depending on the degree of corrosion of RC beam members and the performance degradation factor (ϕ) based on the consequent strength-deformation capacity can be evaluated.