Experimental investigation of polymer fibre concrete beams in shear

This paper presents the results of an experimental study investigating the effectiveness of polymer fibres as shear reinforcement in reinforced concrete beams. The test variables examined include fibre type, fibre volume, shear-span to depth ratio and concrete strength. A total of thirty-three beams were tested until failure under symmetrical four-point loading. This total included six control beams with no fibres and no shear reinforcement, and one beam containing conventional shear reinforcement only. All beams had an overall depth of 250mm (effective depth 213mm) and width of 150mm. Simply supported beams having shear-span to depth ratios of 3.3 and 2.1 were tested. Three polymer fibre types were used in volume fractions of up to 2%. Ultimate shear strength increases of greater than 30% were observed. An equation to predict the ultimate shear strength of polymer fibre reinforced concrete beams is also presented.