Approach to Modeling Corrosion Progression of Epoxy Coated Rebar in Structures with Cracked Concrete

The extent of corrosion of epoxy-coated rebar in marine concrete bridges was found to be generally correlated with concrete chloride diffusivity, D_App, Corrosion initiation had occurred in bridges with high D_App (with values as high as~10^-7 cm²/s), but not for sound concrete locations for bridges with low D_App (as low as ~10^-9 cm²/s). Although no corrosion was observed in sound concrete locations of bridges with low to moderate chloride diffusivity concretes, corrosion may develop at areas with locally deficient concrete. Pre-existing concrete cracks may advance corrosion progression of ECR due to enhanced penetration of chloride ions and other aggressive species to rebar surfaces containing coating defects and extended coating disbondment. Indeed, significant ECR corrosion was observed in several cracked concrete locations on one of those bridges. This paper introduces a deterioration forecast model for ECR in cracked concrete.