Experimental characterization of the bond performance of a new type of glass fibre-reinforced polymer rebar for application in concrete structures

Abstract

This paper presents experimental results obtained from direct pull-out tests of commonly used and a new type of glass fibre-reinforced polymer (GFRP) rebar. The new GFRP rebar, developed by the authors, has a surface structure composed of milled glass fibres and epoxy resin, and its appearance resembles that of ordinary steel rebar. The effects of surface type and increased amounts of milled glass fibres in each rib on bonding with concrete were investigated to characterize the bond performance of the new type of GFRP rebar. The results indicated that the new type of GFRP rebar performed better with a higher bond strength to concrete compared with other tested types of GFRP rebar. Moreover, the rib bearing resistance and energy absorption appeared to increase with increased milled glass fibre in the ribs, which dominated the overall bond behaviour.