Research Progress of Nitrite Corrosion Inhibitor in Concrete

Nitrite inhibitor is a kind of most effective inhibitory corrosion additive used in reinforced concrete. This paper expounded the inhibiting mechanism and physical property of nitrite in concrete. Moreover, the recent progress and application condition at home and abroad were summarized. Meanwhile, corresponding methods for detecting nitrite ion concentration is proposed. Additionally, the inhibition practice on corrosion protection of reinforcing bar in concrete was presented. The long-term inhibiting effectiveness of nitrite ion in concrete when the n(NO2-)/n(Cl-) ratios were above the threshold values in concrete was obtained. Finally it is confirmed that critical molar ratio of n(NO2-)/n(Cl-) increased with differential nitrite ion concentration, higher cathode, and anode area ratio in steel bar.