A FEM Model for the Cathodic Corrosion Protection of Reinforcing Steel in Concrete Structures Exposed to Chloride Contamination

Abstract

This study developed a bi-dimensional model of a steel-reinforced concrete (RC) structure under cathodic protection against corrosion using the Finite Element Model (FEM) based Comsol Multiphysics software. Two small RC samples’ frontal geometry was considered from a reported experimental study, tested here against corrosion in a chloride environment. Those samples had different rebar diameters (10 mm and 16 mm). The reported specific electrochemical parameters and material properties were selected through this numerical investigation. The cathodic protection system’s optimization process was based on identifying the appropriate external applied potential $E_{app}i$ which lowers at minimum the corrosion rate. In this purpose, the first average corrosion current density iFe under the value with minimum corrosion risk (of 0.1 $\mu A/cm^{2}$) was identified for both models. For Model 1 with rebar diameter of 10 mm, a safe iFe value of 0.087 $\mu A/cm^{2}$ was attained $E_{app}i=-0.225V$, and for Model 2 with rebar diameter of16 mm, $i_{Fe}=0.085\mu A/cm^{2}$ at $E_{app}i=-0.15$ V.