Manufacture and Testing of a Hybrid Beam Using a Pultruded Profile and High Strength Concrete

Abstract

An improved design concept for a hybrid FRP-HSC (fibre reinforced polymer – high strength concrete) beam is presented. To reduce the initial cost of the beam, an “off the shelf” pultruded FRP profile and CFRP (carbon fibre reinforced plastic) laminate are combined with HSC. The HSC block and the CFRP laminate are bonded to the pultruded profile. The bonded system is then wrapped with a GFRP (glass fibre reinforced plastic) laminate to mitigate any debonding of the concrete, and hence create a full composite action between the concrete and the profile. The major feature of the proposed design is that it does not mimic that of reinforced concrete as reported previously. The CFRP laminate is not designed to fail first to serve as a warning of imminent failure, but rather to enhance the stiffness of the beam by compensating for the lack of stiffness of the GFRP profile. Experimental results have shown that this approach is successful. The much sought after pseudo ductility is fully achieved through the brittleness of the HSC block instead of that of the CFRP laminate, as reported in previously published similar works.