Performance of ductility and strengthening effect of hybrid fibre reinforced polymer laminates on high strength concrete beams

Concrete is predominantly utilized in various types of construction, yet it faces challenges in improving its strength and durability. To address these issues, researchers are exploring innovative methods such as the use of FRP composites. During the assessment of existing structures, structural defects are often identified, especially in older buildings that may require retrofitting. This study intends to assess the ductility performance and static behavior of externally bonded hybrid FRP laminates in high-strength concrete (HSC) beams with different layer combinations. For this research, two types of glass and carbon Fibre Reinforced Polymer were employed in the form of hybrid Fibre Reinforced Polymer laminate. A total of 17 rectangular beams were Cast and strengthened using Glass Fibre Reinforced Polymer and Carbon Fibre Reinforced Polymer for the current study. Among the seventeen cast beams, one served as the control concrete beam, while the other sixteen were reinforced with hybrid Fibre Reinforced Polymer laminates, which included both glass and carbon Fibre. Each beam measures 150 × 250 × 3000 mm. The study parameters considered include first crack load, deflection at first crack load, yield load, deflection at yield load, crack width, ultimate load, deflection at ultimate load, deflection ductility, deflection ductility ratio, energy ductility, and energy ductility ratio for hybrid Fibre Reinforced Polymer laminated high-strength concrete beams, as well as control concrete beams. The test results indicate enhanced flexural stiffness, increased strength, sufficient ductility, and composite action in HSC beams reinforced with externally attached hybrid Fibre Reinforced Polymer laminates.