Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Components: Field Tests

AbstractThe results of field tests to evaluate methods designed to make epoxy-coated reinforcement (ECR) more resistant to corrosion are reported. Reinforcing bars coated with epoxies designed to have improved adhesion to the steel, concrete containing corrosion inhibitors, bars with a primer coating containing microencapsulated calcium nitrite applied prior to epoxy application, bars coated with zinc prior to epoxy application, and conventional uncoated bars are evaluated based on corrosion rates and losses using field exposure tests that closely simulate conditions in bridge decks subjected to deicing salts. Coatings are penetrated to simulate damage that occurs during construction. Even when damaged, epoxy-coated bars exhibit significantly lower corrosion rates based on total area than conventional reinforcement. The corrosion resistance of bars with improved adhesion does not increase compared to conventional ECR. Bars with a layer of zinc underneath the epoxy exhibit performance comparable to conventional ECR; this is in contrast to laboratory tests in saturated concrete where the zinc-and-epoxy coated bars exhibited poor performance.