The impact of the anchorage on the shear capacity of reinforced concrete beams

Abstract

This paper presents an experimental study on shear strengthening of reinforced concrete (RC) beams with PBO-FRCM composites. Key parameter of this study is the presence of composite anchorage. PBO-FRCM (Fabric-Reinforced Cementitious Matrix) composites consist of mineral mortar and PBO (p-Phenylene Benzobis oxazol) composite fibres. The most common failure mechanism of FRCM composites is debonding of the fibers from mineral mortar with no rupture of fibres, due to inappropriate coverage of all fibers by the mortar. To prevent premature debonding of the composite and increase the effectiveness of FRCM strengthening suitable anchorage should be used. In this case, experimental research was conducted on T-shaped RC beams strengthened in shear using PBO-FRCM with anchorages The study consisted of 5 beams, one of which was a control beam, one was strengthened without anchorage and the other three were strengthened with GFRP rebar anchorage. All beams were loaded until failure. Deformation, deflection and the width of cracks were recorded for each level of loading. The failure mechanisms of beams were analysed and described. The results obtained from research showed that the use of FRCM composites increased the shear capacity and had an impact on better use of the properties of the composite material.