Reinforced-concrete cover cracking due to the pressure of corrosion products

Reinforcement corrosion is one of the most important phenomena that reduce the service life of the reinforced concrete structures. Steel corrosion reduces the strength and bond of the reinforcement and the oxides formed cause internal stresses that crack the concrete cover. The prediction of the evolution of these effects is a problem that involves chemical and mechanical aspects. The phenomenon is not well known and quantitative descriptions of development and magnitude of stresses produced by a corroding rebar to concrete are scarce and although there are several models in the literature they do not universally reproduce the experimental results. This work presents a summary of the available experimental evidence on the amount of internal expansion needed at the reinforcement level for concrete cover to crack and formulas to estimate the expansion. Also, results are presented on the pressure needed for concrete cover to crack together with the experimental technique used for the verification of the assumptions and crack propagation analysis.