Laboratory evaluations were performed to determine the effectiveness of migrating corrosion inhibitor (MCI) for reinforced concrete. In this study, concrete densities and application methods were compared. Bode and Nyquist plots showed high resistance polarization resistance values for concrete treated with inhibitor. XPS analysis verified the presence of MCI and chloride molecules on the steel rebar surfaces, and XPS depth profiling showed a 100 nm amine-rich layer (inhibitor) and chloride ions on the rebar confirming that MCI had migrated through the concrete coverage to suppress chloride ions corrosiveness. In regard to how MCI is applied, directly to the rebar, by surface impregnation, or in a mortar coating, the effects were not apparent in the monitored corrosion potentials, bode and Nyquist plots for the samples. Additional data is required to make any conclusion about the effectiveness of an application method. At this time, the inhibitor coated rebar samples show the highest polarization resistance.
Keywords: migrating corrosion inhibitors, reinforced concrete, XPS, amino carboxylate chemistry