Strength decay of RC sections for chloride attack

Abstract

Purpose Corrosion of reinforcement, and mainly the one induced by chloride attack, is one of the leading causes of deterioration in reinforced concrete structures. Then, it is very important to develop a simplified analytical tool, able to simulate the corrosion processes and the consequences for the structural safety. Design/methodology/approach Aim of this paper is the definition of a simplified integrated procedure, able to predict the decay with the time of the bending moment and axial force resistance of a reinforced concrete section, exposed to a chloride attack. Starting from various literature findings, the rebar mass loss in time is evaluated and related to the chloride distribution and content in time. Then the mechanical properties of the corroded rebars are evaluated by means of strength decay laws developed by the authors. Finally, moment curvature relationships and bending moment – axial force (M-N) interaction envelopes are defined. Findings The strength variation with the time can be easily evaluated and then the life cycle and the timing of repair or rehabilitation strategies can be estimated. Originality/value The proposed methodology can be considered a very simple, but useful tool for a first analysis of the strength reduction in time, due to chloride pitting corrosion, before performing more complex and time-spending analyses.