Research on Inhibiting Performance of Compound Corrosion Inhibitors Based on Nitrite

To solve rebar corrosion in existing concrete structures, two test methods, adding corrosion inhibitors into concrete and applying corrosion inhibitors on the existing concrete surface by brushing and pouring and composite repair, combined with natural potential, XRD and SEM, were used to comprehensively evaluate the performance of nitrite-based compound corrosion inhibitors. The research results show that nitrite has a better inhibitory effect than phosphate, and when the respective mass fraction of hydrogen phosphate and sodium nitrite is about 1.5%, the rust inhibition effect is the optimum. Brushing, perfusion, and composite repair can all play a good role in inhibiting corrosion of which composite repair is the best. The addition of phosphate can improve the macrocell corrosion caused by the low dosage or uneven distribution of nitrite.