Modelling of interaction between corrosion-induced concrete cover crack and steel corrosion rate

Chloride-induced corrosion of steel reinforcement in concrete may cause severe damage to RC structures. This paper examines the interaction between corrosion-induced cover crack growth and corrosion propagation. The coupled micro- and macro-cell corrosion process involved in a typical chloride-induced corrosion is numerically simulated. Both oxygen concentration and electrical potential distribution within concrete cover are considered in the electrochemical analysis. A uniform thick-walled cylinder model is formulated to simulate the cover surface crack width evolution. Results show that macrocell corrosion rate may not change so much while microcell corrosion rate increases a lot as oxygen permeability increases with corrosion-induced cover crack.

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► Coupled micro- and macro-cell corrosion process is numerically simulated.
► Oxygen is a crucial factor influencing corrosion rate under cracked concrete cover.
► Microcell corrosion dominates corrosion process after concrete cover cracking.
► Corrosion-induced longitudinal crack accelerates subsequent deterioration process.