Chloride-induced corrosion of steel reinforcement in concrete may cause severe damage to RC structures. Longitudinal cover cracks may form during the rust expansion process. Currently, there are relatively few numerical methods for modeling the effects of crack on steel corrosion rate....[ Read more ]

Chloride-induced corrosion of steel reinforcement in concrete may cause severe damage to RC structures. Longitudinal cover cracks may form during the rust expansion process. Currently, there are relatively few numerical methods for modeling the effects of crack on steel corrosion rate.

This study 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 under three controlling mechanisms – chloride control, oxygen control and resistivity control. Both oxygen concentration and potential distribution within concrete cover are considered in the electrochemical analysis. A uniform thick-walled cylinder cracking model is formulated to simulate the cover surface crack width evolution with rust expansion. A quantitative relationship between surface crack width and concrete cover durability properties have been developed.

Results show that macrocell corrosion rate may not change so much in case of corrosion-induced longitudinal crack. On the other hand, microcell corrosion rate may increase a lot as oxygen permeability increases with corrosion-induced longitudinal cover crack. Thus, the substantial increase in total corrosion rate may lead to accelerated cover cracking process.