Reinforced concrete (RC) beams are designed to resist bending moments and shear forces generated by dead loads, live loads and other structural actions. Over time, however, changes in building use, increased loading requirements, deterioration of concrete, corrosion of reinforcement and deficiencies in the original design can reduce a beam’s load-carrying capacity. In such cases, structural strengthening can help improve performance without requiring complete replacement of the existing member.
Flexural strengthening using fibre-reinforced polymer (FRP) laminates is an established technique for upgrading reinforced concrete beams. It involves bonding high-strength composite materials to the tension face of a beam to improve its resistance to bending. The additional reinforcement helps the beam resist tensile stresses that develop when it bends under load.
FRP laminates are particularly useful in rehabilitation projects where increasing the beam’s dimensions through conventional concrete jacketing may be difficult or undesirable. Their relatively low weight, high tensile strength and resistance to corrosion make them suitable for many building and infrastructure applications. However, successful strengthening depends on structural assessment, appropriate material selection, sound bonding, correct installation and suitable detailing.
