Evaluation of Multiple Corrrosion Protection Systems and Corrosion Inhibitors for Reinforced Concrete Bridge Decks

Abstract

The corrosion performance of different corrosion protection systems is evaluated using the mortar-wrapped rapid macrocell test, bench-scale tests (the Southern Exposure, cracked beam, and ASTM G109 tests), and field tests. The results indicate that a reduced water-cement ratio improves the corrosion resistance of conventional steel in uncracked concrete. The use of a corrosion inhibitor improves the corrosion resistance of conventional steel in both cracked and uncracked concrete, but provides only a very limited improvement in the corrosion resistance of epoxy-coated reinforcement. Increased adhesion between the epoxy coating and reinforcing steel provides no improvement in the corrosion resistance of epoxy-coated reinforcement. The corrosion losses for multiple-coated reinforcement are comparable with those of conventional epoxy-coated reinforcement. Pickled 2205 stainless steel demonstrates excellent corrosion resistance. ECR, ECR with increased adhesion, and pickled 2205 stainless steel are the most cost-effective corrosion protection systems based on the economic analyses of a 216-mm (8.5-in.) thick bridge deck over a 75-year design life.