Corrosion Evolution of Scaled Rebar in Concrete under Dry/wet Cyclic Condition in 3.5% NaCl Solution

The evolution of water-cooled scaled rebar corroded in concrete under alternate dry/wet corrosion acceleration condition with 3.5% NaCl solution was studied by EIS, potential monitoring, SEM and XRD techniques. The results show that the corrosion evolution of rebar undergoes uniform corrosion in three stages. The initial stage is described as the charge transfer process, which starts from the concrete curing period due to the porous scale of water-cooled rebar. The second stage is described as the corrosion acceleration process which attributes to the gradually increase of scale pores caused by Cl- penetration. The third stage is described as the steady corrosion process due to the diffusion limitation through a thick rust layer.