The effect of chloride-induced steel corrosion on service life of reinforced concrete structures

Chloride-induced corrosion is one of the most important deterioration mechanisms in reinforced concrete structures. This study presents detailed theoretical models for predicting service life of reinforced concrete structures exposed to chloride attack. Three stages are considered in the corrosion process: the diffusion period, the rust accumulation period and the crack propagation period. For the diffusion period, the fully coupled moisture diffusion and chloride penetration in concrete are considered as the main driving forces of the deterioration process. Two-way coupled diffusion equations are used to characterize the length of this period. For the rust accumulation period, the chemo-mechanical coupling between the formation of the rust and the development of the interface pressure is considered as the driving force. For the crack propagation period, the interface pressure induced by the rust expansion and the fracture resistance of the cracked concrete determine the rate of crack propagation. The theoretical models developed in the present study are capable of simulating the entire process of the chloride-induced corrosion damage, and predicting the service life of reinforced concrete structures.