Testing Prefabricated (Purple) Epoxy Coated Reinforcement

摘要

Prefabricated epoxy-coated reinforcement is used increasingly in reinforced concrete construction in which high corrosion resistance is required. It is well established that epoxy coating reduces bond strength between reinforcement and concrete, and some tests have found that bond strength decreases as coating thickness increases. For prefabricated epoxy-coated reinforcement, it can be difficult to maintain coating thicknesses within required tolerances 175 to 300 im. Beam-end tests were carried out on uncoated bars, bars with green epoxy coating (203 im coating thickness), and prefabricated (gray) epoxy coating (203 to 508 im coating thickness). Tests showed that epoxy coating reduces bond strength, with similar reductions for green and gray coatings. In some cases, bond strength decreased with increasing coating thickness, but for the range of thicknesses investigated the reduction factor of current building codes was found to be conservative.