A novel and effective anchorage system for enhancing the flexural capacity of RC beams strengthened with FRCM composites

Abstract

Previous experimental studies revealed that anchorage systems were able to increase the efficiency of fiber reinforced polymers (FRP) in terms of the flexure or shear enhancements and ductility performance of the structural members. This study was conducted to investigate the suitability and effectiveness of two anchorage systems for enhancing the bond performance of fiber reinforced cementitious matrix composite (FRCM), a more recent strengthening technique using a cementitious-based binding system. In the interest of improving its flexural performance, two anchorage systems were examined here: a glass spike anchor and a novel U-wrapped anchor. The novel U-wrapped anchor is a PBO strip where its’ ends had only the fabrics in the longitudinal direction that gathered and anchored into the concrete using epoxy adhesive agent. The idea behind anchoring the ends of the U-wrapped PBO strip into RC beams was to rely on the high tensile strength of the PBO strip to control the premature debonding of the FRCM composite. Real-scale simply supported RC beams were examined under the effect of strengthening with different reinforcement ratios and with and without anchorage systems engagement. Test results revealed the contribution of anchorage systems in preventing or delaying the FRCM debonding failure mechanism and enhancing the flexural performance of strengthened beams.