Ethanolamines corrosion inhibition effect on steel rebar in simulated realkalized concrete environments

Abstract

ABSTRACT This paper reports the corrosion inhibition effect of the realkalization and corrosion inhibitors combination treatment on steel rebars. First, the corrosion was studied in simulated carbonated concrete and simulated realkalized concrete environments and then compared with the corrosion, while realkalization-corrosion inhibitor treatment was applied. The corrosion inhibitors studied are monoethanolamine (MEA), dimethylethanolamine (DEMA) and triethylenetetramine (TETA). Through the electrochemical measurement; the potential of steel rebars in realkalized environment containing MEA and DMEA shifted in positive direction by 84 mV and 66 mV; the current destiny of each group decreased by 3.76 and 2.33 μA/cm2, respectively. Unlike the addition of TETA shifted the potential in negative direction by 281 mV and increased the current density by 27.72 μA/cm2. Comparing steel rebars surfaces, the realkalization-corrosion inhibitors groups showed a better inhibition effect than the two control groups (simulated carbonated concrete and simulated realkalized environments). Among the corrosion inhibitors used, MEA has the best corrosion inhibition effect in the electrochemical realkalized concrete environment, it can form a protective film on the steel rebars through physical and chemical adsorption, which can effectively inhibit the corrosion of steel rebars. The result confirms that, by the combination of MEA and electrochemical realkalization, the corrosion inhibition in carbonated reinforced concrete can improve significantly.