Towards innovative FRP fabric reinforcement in concrete beams: concrete–CFRP bond

The paper reports results of an experimental investigation into load response and failure behaviour of rectangular prismatic concrete beams reinforced with a combined flexural and shear reinforcement system made from carbon-fibre-reinforced polymer (CFRP) fabric. It is shown that CFRP U-channels with aggregate coating and an anchorage system consisting of a lipped channel section with intermittent closed loops were found to provide improved composite action between the CFRP reinforcement and concrete. These CFRP channels also ensured adequate strength and ductility before failure. Possible modes of failure of the beams are discussed, as is the effect of the design parameters on the failure mode and the failure load. It is anticipated that the findings of this paper could be effectively used in other applications such as non-prismatic concrete geometries and as permanent formwork/reinforcement in thin concrete members where the flexible characteristics of dry CFRP fabrics are most useful.