Practical approach for estimating flexural strengths of corroded RC members considering bond strength degradation

Abstract

This study conducts parametric analyses to identify the bond strengths of corroded reinforcement by using a nonlinear model proposed in previous study, where the compressive strength of concrete (fc′), cover thickness of concrete (Cx), diameter of reinforcing bars (db), and corrosion degree (ωcorr) are chosen as key variables. On this basis, a simplified bond strength equation and corresponding flexural strength model were derived to facilitate practical applications. For verification of the proposed model, flexural test results of corroded reinforced concrete (RC) members are collected from literature, and its accuracy and applicability are affirmed by comparing the test and analysis results. According to proposed analytical model, development length required for corroded reinforcement to be yielded is less than that specified in the current design code when the ratio of net cover thickness to diameter of reinforcement (Cx/db) is greater than 4.0. While, when Cx/db is less than 1.5, it appeared that the required development length increases significantly even at low corrosion degrees less than 5%.