Concrete is one of the vital materials for infrastructure development due to its versatile application. Globally its usage is second to water. Concrete is one of the most widely used construction materials. Since the day of its advent, concrete has been changing material and technology. Due to the growing need for performance and durability of concrete, there has been a continuous search for upgrading the properties of concrete. Concrete is the most versatile construction material and is used in a wide range of civil engineering structures and structural elements all over the world.
In recent years, the use of externally bonded fiber-reinforced polymer (FRP) composites has become increasingly popular for the repair and retrofitting of concrete structures. The popularity of FRP composites is due to their well-known advantages, including a high strength-to-weight ratio and excellent corrosion resistance. One important application of FRP composites is as a confining material for the retrofitting of existing Reinforced Concrete (RC) beams with FRP wrapping. Reinforced concrete (RC) beams with outer confinement provided by Fiber Reinforced Polymers (FRP) have their properties enhanced, especially increased ductility and maximum load-carrying capacity.
According to the research results, hybrid GFRP/steel-reinforced concrete beams with normal effective reinforcement ratios exhibited good ductility, serviceability, and load-carrying capacity. The H-CF/GF-RP strengthening leads to a significant increase in ductility with a slight influence on the stiffness of strengthened beams. The use of twin layer Glass-Carbon fibers composite material for strengthening reinforced concrete beams is very efficient. By optimizing the amount of CFRP it is possible to balance strength recovery with control of failure mode. The use of a hybrid reinforcement system increased ultimate load capacity and ductility. There have been test results available that show both deflection and energy absorption are drastically reduced when beams are strengthened with bonded CFRP plates without external anchorages.
