Corrosion of Reinforcing Bars in Concrete

The causes and mechanisms of corrosion of reinforcing bars in concrete are described in terms of the practical issues as well as the electrochemistry. The parameters affecting corrosion are (i) the ingress of aggressive species, such as chlorides, which break down the protective film on the reinforcing bar and (ii) the amount of those species necessary to do so. The former is largely controlled by the concrete properties while the latter is a function of the type and condition of the reinforcing bar. Thus, the influence of the cementitious components of concrete, the water/cementitious materials ratio and the presence of cracks in the concrete cover, on the ingress of aggressive species is considered and the various currently available reinforcing bar materials and their merits are reviewed.