Effects of Ultraviolet Exposure on Corrosion Performance of Epoxy-Coated Reinforcement.

Epoxy-coated reinforcement (ECR), with and without penetrations through the epoxy, was subjected to an accelerated weathering program under ultraviolet (UV) light following Cycle 1 of ASTM G154, simulating outdoor exposure in North America for periods ranging from 1.2 months to 1 year. The corrosion resistance of the bars was evaluated using the ASTM A955 rapid macrocell test. As a control, the corrosion resistance of bars not subjected to the accelerated weathering program was also evaluated. After accelerated weathering equivalent to approximately 1.2 months of outdoor exposure, the corrosion resistance of epoxy-coated bars with penetrations in the coating was reduced, with corrosion losses three to six times greater than ECR without UV light exposure. Even ECR without penetrations through the coating showed a loss in corrosion protection when subjected to the equivalent of 1 year of outdoor exposure. ECR should be stored in a manner that protects it from exposure to UV light. The existing guidelines in ASTM D3963 limiting unprotected exposure to 2 months are not sufficient to protect the coating from damage; limiting exposure to 1 month or less should be required. [ABSTRACT FROM AUTHOR]