Theoretical elucidation on the on-site measurements of corrosion rate of reinforcements

The main goal of this paper is the theoretical elucidation of the three on-site measurements of corrosion rate of reinforcements provided by Andrade and Alonso [On-site measurements of corrosion rate of reinforcements. Constr Build Mater 2001;15:141-5]. First, according to Ohm's law and the condition of conservation electrical charge, the relationship between corrosion current (Icorr) and electrical resistivity of concrete (ρ) has been established. Secondly, on the basis of corrosion cracking model, the empirical formula with which the attack penetration defined as the loss in cross radius of steel reinforcement in concrete structures equal the representative value of corrosion current times the time after corrosion started could be elucidated. Finally, in accordance with the one-dimensional linear diffusion equation with diffusion and chemical reaction terms, the evaluation of the log(depth)-log(time) can be made clear from the carbonation or chloride threshold front beyond the rebar. The implication of the present results theoretically enhanced the corrosion rate of reinforcements to be implemented into the corrosion prediction for the laboratory and on real size structures on-site.