Abstract
This paper presents experimental investigations of the interfacial bond behaviour of different types of rebar (steel, sand-coated GFRP, and helically-wrapped GFRP bars) and cementitious composites with and without polyvinyl alcohol (PVA) fibre. A total of 27 cubic specimens were prepared, and different PVA fibre volume fractions of 0%, 1% and 2% were added. The effects of PVA fibre on the compressive strength and interfacial bond strength were not significant. However, PVA fibre in engineered cementitious composites apparently changed the failure mechanisms during the pullout of both the steel and the helically-wrapped GFRP bars. The increase in PVA fibre volume fraction significantly improved the ductility of the matrix. Specifically, the helically-wrapped GFRP bar demonstrated the greatest improvement in ductility, while the sand-coated GFRP bar resulted in frictional pullout of the rebar due to the complete slip failure of the resin, regardless of the fibre content. Finally, the application of PVA-ECC to the helically-wrapped GFRP bar was found to be effective as replacement for steel rebar with respect to the ductility of the interfacial bond.