Electro-chemo-physical analysis for long-term reinforcement corrosion within the reactive system of concrete

Abstract

This paper presents an electro-chemo-physical model for analyzing long-term chloride-induced reinforcement corrosion in concrete structures. The integration of electrochemical and thermodynamic analyses enables the proposed model to capture the influence of simultaneous reactions within concrete on the corrosion process. The model is validated against experiments, where the necessity of considering the complicated reactions within concrete in long-term corrosion modeling is underscored. Building upon experimental observations and numerical explorations, a potential corrosion acceleration effect resulting from Friedel's salt dissolution in a longer term of corrosion propagation is discovered. Thereafter, a new qualitative model for describing the reinforcement depassivation process in concrete is proposed, along with discussions on governing mechanisms. From a computational perspective, the study also identifies hematite and magnetite as thermodynamically stable rusts under different concentrations of Fe²⁺ and O₂. The proposed model and discoveries are poised to contribute significantly to scientifically robust predictions of deterioration and remaining service life for aging reinforced concrete structures.