Bond performance of polystyrene aggregate concrete (PAC) reinforced with glass-fibre-reinforced polymer (GFRP) bars

This paper concerns the bond performance of GFRP bars in polystyrene aggregate concrete (PAC) by the proposed concentric pullout test. Identical specimens reinforced with mild steel bars were used for comparison. The bond performance including the mode of failure and bond strength was studied with varying polystyrene aggregate content, concrete strength, embedment length, shape and surface treatment of the bars. Empirical formulae were developed for the estimation of development length on the basis of the pullout test results. The bond development length (ld) determined according to ACI Building Code was used for comparison. Considering the bond performance, the sand-coated GFRP bar gave the most promising results with the highest bond strength attained. In particular, the bond strength was found increased with the compressive strength and concrete density of PAC. Besides, the bond development length for PAC reinforced with GFRP bars can be predicted satisfactorily using the ACI equation.