The roles carbonate and bicarbonate ions play on pre‐passive HRB400 rebars in simulated pore solutions of deteriorating concrete

Abstract

To evaluate the corrosion behavior of HRB400 rebars during the aging process of concrete, corresponding simulated concrete pore solutions were proposed. Using electrochemical measurements and XPS analysis, the depassivation conditions, properties of the pre‐passive films, and rebars corrosion rate were discussed. The effects of carbonate and bicarbonate ions, pH and chloride on the corrosion behavior of pre‐passive HRB400 rebars were investigated. Results show that the influence of carbonate and bicarbonate ions on the pre‐passive HRB400 rebars is reversed before and after its depassivation: before depassivation, carbonate and bicarbonate ions are detrimental to the stability of passive film, but beneficial after depassivation.

Effects of pH and Cl− Content on Degradation Process of Pre-Passivated Stainless Steels in an Alkaline Solution

“…In the combination of above two factors, the passive film formed on the steel rebars is no longer chemically stable and starts to dissolve, eventually leading to the depassivation of the steel rebars. [3][4][5][6][7][8] In order to reduce the deterioration of concrete structures induced by the corrosion, the application of SSs is one of the most reliable solutions to guarantee the durability and service life of reinforced concrete structures in highly aggressive environment. [9][10][11] Recently, with the increasing demand for cost-saving materials, the duplex stainless steels (DSSs) are increasingly being used as the structural material to replace the corrosion resistance alloy in power plants, petrochemical industries and marine constructions.…”