Assessment of Electrical Injection of Corrosion Inhibitor for Corrosion Protection of Reinforced Concrete

Abstract

Chloride ingress is the major cause of rebar corrosion that deteriorates reinforced concrete structures in chloride-laden environments. A recently emerged electrochemical technique—the electrical injection of corrosion inhibitor (EICI)—shows its potential in protecting a rebar from chloride attack by driving corrosion inhibitors to the rebar surface under an externally applied electric field. Potential applicability of EICI as a routine electrochemical treatment for corrosion protection is assessed. A comprehensive evaluation of currently available organic cation-based inhibitors was conducted on the basis of the measured corrosion inhibition performance and diffusion coefficient of each inhibitor. With the use of a two-dimensional finite element model, the concentration evolution of the selected inhibitors and chloride were predicted on the rebar surface and in concrete, and the applicability of EICI was examined thereafter. Important aspects of EICI were studied including mainly inhibitor type, magnitude of applied current density, and treatment time. Recommendations about EICI practice were made accordingly.