Behaviour of Reinforced Concrete Beams Strengthened by Ultra-High Performance Concrete Overlays Reinforced with Glass Fibre Polymer Bars

This thesis explores the flexural performance of reinforced concrete (RC) beams strengthened with ultra-high-performance concrete (UHPC) overlays reinforced by glass fiber reinforced polymer (GFRP) bars. Twelve beams were tested to evaluate the effects of UHPC thickness, GFRP ratio, length, and bonding type. Results showed that GFRP-reinforced UHPC overlays significantly enhanced ultimate load capacity—up to 267%—and ductility compared with control beams. Finite element simulations using ABAQUS closely matched experimental results. The developed analytical model provided accurate predictions of ultimate load capacity, confirming that UHPC-GFRP systems offer an effective and durable solution for flexural strengthening of RC structures.