Design rules for bond strength of epoxy-coated bars

Epoxy-coated reinforcement has been commonly used to inhibit reinforcement corrosion in severe environments throughout the world. Because of factors such as reduced adhesion associated with the epoxy coating, longer anchorage lengths are required to fully develop epoxy-coated reinforcement compared with uncoated reinforcement. The Concrete Structures Standard of Australia, AS3600 does not specify rules for epoxy-coated reinforcement. This paper provides a basic background in understanding bond between epoxy coated bars and concrete. Modifications to the existing recommendations in AS3600 for design of splices and anchorage of uncoated reinforcement are proposed for epoxy-coated reinforcement. Finally the results of a study conducted at the University of Minnesota to investigate the bond behaviour of epoxy-coated bars in micro-silica concrete are briefly presented.