08311 - Corrosion of Epoxy Coated Rebar in Cracked Marine Substructure Concrete

Epoxy coated reinforcement (ECR) has been used in Florida from the 1970s to 1990s but has been discontinued due to the observation of severe corrosion in some ECR bridges after short service times. Corrosion projections have been made in earlier investigations based on corrosion initiation and propagation concepts but did not consider the presence of structural cracks. The current research in progress reexamines Florida ECR bridges after an additional decade of service, to determine if corrosion propagation took place as projected for bridges with high permeability concrete. The corrosion condition of ECR in cracked concrete locations is examined to aid in improving corrosion projection for those conditions. Field survey and laboratory examinations confirmed expectations of active corrosion in bridges with high permeability concrete. In bridges with low permeability concrete, little to no corrosion was observed with one exception. In that case, significant local corrosion was observed at near tide level locations that had relatively wide structural cracks. That corrosion was present despite large concrete cover, high quality concrete, and short service time.