Experimental Studies on Shear Behavior of FRP-UHPC Hybrid Beams

Steel corrosion poses a significant challenge in infrastructure construction globally. Fiber Reinforced Polymer (FRP) offers a high-performance solution with its lightweight, corrosion-resistant, and high-strength properties, making it widely used across various fields. Similarly, Ultra High Performance Concrete (UHPC) has emerged over the past 30 years as an innovative cement-based composite with exceptional mechanical properties and durability. When compared to FRP-concrete composites, FRP-UHPC composites provide superior load-bearing capacity, reduced weight, and enhanced durability. To study the process, phenomena, and modes of damage of hybrid beams with various shear-to-span ratios and concrete conditions, four glass fibre-reinforced polymer (GFRP) profile-normal concrete hybrid beam specimens and one GFRP profile-ultrahigh-performance concrete (UHPC) hybrid beam specimen were designed and tested in four-point bending tests. The stiffness and bearing capacity of the GFRP profile-normal concrete hybrid beams gradually decreased as the shear-to-span ratio increased. The GFRP profile-UHPC hybrid beam members had better load-bearing capacity and stiffness than the fibre-reinforced polymer (FRP) profile-normal concrete hybrid beam members. When the UHPC underwent compressive damage, the hybrid beam displayed obvious ductility as opposed to the GFRP profile-normal concrete hybrid beam, which had insufficient ductility and showed no obvious evidence of damage. According to a parametric study, the ultimate load capacity of the hybrid beam declined as the shear-to-span ratio gradually rose.