Inhibiting behavior of nitrites in corrosion of reinforcing steel in micropore solutions

Abstract

Measurements of the corrosion rate of corrugated steel bars have been carried out in solutions simulating electrolitic chloride enviroments in the micropores of concrete in the initiation period. It has been studied the effect of sodium nitrite as a corrosion inhibitor when added to the mentioned solutions. The solutions for the experiments were prepared by addition of different volumes of FeCl2 0.2 M into a saturated solution of calcium hydroxide until the target pH was reached in each case. This is the soluble compound produced during the corrosion of steel as a result of chloride attack. It has been observed a significant improvement in using nitrite as inhibiting agent in these systems, but its efficiency decreases when the pH is reduced. The corrosion seems to be related to the Cl-]/OH-] ratio in three different regions of pH identified from acid to alkaline pH values. © 2010 Taylor & Francis Group, London.