Effect of Nitrite Concentration and pH on Steel Corrosion Induced by Sulfate in Simulated Concrete Pore Environment

Abstract

The effect of nitrite on steel corrosion induced by sulfate in three simulated concrete pore environments has been investigated by means of half-cell potential, linear polarization resistance and visual examination, as well as sulfate-induced corrosion is compared with chloride-induced corrosion. The results indicate that with the presence of nitrite, sulfate-induced corrosion can be inhibited effectively. Sulfate threshold level increases with the increasing of nitrite concentration and highly alkaline environment plays an important role in assisting nitrite to inhibit sulfate-induced corrosion. Chloride-induced corrosion is more prone to initiate than sulfate-induced corrosion in highly alkaline environment but in neutral environment, when nitrite content is equal to or less than 0.053mol/L, sulfate-induced corrosion is more likely to occur than chloride-induced corrosion.