Parameters Governing Corrosion Protection Efficacy of Fusion-Bonded Epoxy Coatings on Reinforcing Bar

The purpose of this study was to investigate the epoxy-coated reinforcing steel (ECR) corrosion abatement condition of specimens extracted from bridge decks in Virginia. The following parameters were investigated: coating thickness, coating residual adhesion by the peel test, holidays, coating damage, the color of the coating, the color of the corrosion products under the coating, the glass transition temperature and the coating degree of curing, and the coating moisture content. The results showed that the epoxy coating on the extracted steel samples were not fully cured during the manufacturing process. Additionally, the samples investigated presented significant permanent adhesion loss with little or no epoxy coating residue present on the bar surface. Furthermore, the analysis shows that once adhesion is lost, corrosion will proceed unimpeded under the coating even in the absence of chlorides. [PUBLICATION ABSTRACT]