Strengthening of RC beams using glass fibre polymer composites

Fibre reinforced polymer (FRP) composites have been established as an alternative method for rehabilitation and strengthening of concrete structures. In this project, reinforced concrete (RC) beams had been externally strengthened with glass fibre reinforced polymer (GFRP) sheets. A series of static tests was carried out in order to investigate the load capacity and member failure by altering the number of bonded layers (two or four). Either U-jacketing schemes or a laminate bonded at the bottom of the beam (tension face) were used. Results show that, by the use of U-Jackets, the deflection is reduced and the load capacity of the member is increased up to four times compared with the conventional RC beams. Two failure modes were observed; failure of the GFRP close to the mid span area (when 2-layers GFRP had been used) and a shear failure between the GFRP sheet and the concrete surface at the end of the beams (when 4-layers GFRP were used). To increase the capacity of the beam to a value higher than that obtained for the four layers, an anchorage system was placed around the beams at their ends and allocated by cure. The system proved to be a satisfactory method for upgrading RC beams.