The corrosion behavior of reinforcing steel bars depends on the protective oxide scale formed on its surface.Chloride ions
degrade the oxide and cause localized breakdown and pitting.Chloride-induced corrosion of reinforcing steel bars in concrete begins when the chloride content of concrete immediately next to the rebar reaches a critical threshold value.In the experiment,extensive studies have been performed on the reintorced concrete with protective coatings in terms of resistance to chloride ions permeation of the coated concrete.After a laboratory accelerated cyclic dry-wet test,the tested reinforced concretes without and with coatings were then evaluated with cycle polarization in NaCl solution to assess the pitting tendencies of reinforcing steel bars.The penetration test of high pressure water was used to study the influence of
concrete protective coatings on the penetration of reinforced concrete in comparison with those of cyclic polarization.The results showed that concrete protective coatings could reduce
chloride ion penetration significantly and the corrosion of reinforced bars.To conclude,the applicability of cyclic polarization might be used to examine the dissolution characteristics of oxide scale on reinforced bars and the pitting tendency of reinforced bars in the environment containing chloride ion.It is hoped that this study will eventually lead to a better understanding of the role of chloride ion in pitting corrosion of the reinforced bar.