Title:
Effect of Nitrite as a Corrosion Inhibitor in Contaminated and Chloride-Free Carbonated Mortar
Author(s):
C. Alonso and C. Andrade
Publication:
Materials Journal
Volume:
87
Issue:
2
Appears on pages(s):
130-137
Keywords:
carbonation; concretes; corrosion; corrosion resistance; mortars (material); nitrites; reinforcing steels; sodium nitrite; Materials Research
DOI:
10.14359/1937
Date:
3/1/1990
Abstract:
Paper studies and quantifies the effect of NaNO2 as a corrosion inhibitor when added to the mortar mix specimens made with varied cement types. A set of specimens was also fabricated with 2 percent of CaCl2. All of the specimens were rapidly carbonated. It was found that the attack was reduced and even completely avoided, depending on the type of cement and the NaNO2 proportion employed, when carbonation was the sole aggressor. When chlorides and carbonation acted together, however, the proportions of NaNO2 used (2 and 3 percent) were not adequate to reduce the attack, so that the reinforcing steel corroded at a rate similar to when no nitrites were present in the mix. Polarization-resistance and electrochemical-impedance measurements were used to track the corrosion process.