Use of carbon fiber laminates for strengthening reinforced concrete beams in bending

The use of Fiber Reinforced Polymer (FRP) is becoming a widely accepted solution for repairing and strengthening ageing in the field of civil engineering around the world. In the present paper, experimental study designed to investigate the flexural behavior of reinforced concrete beams strengthened with CFRP laminates attached to the bottom of the beams by epoxy adhesive subjected to transverse loading. A total of five beams having different CFRP laminates configurations were tested to failure in four-point bending over a clear span 1900mm. Four beams were strengthened by changing the levels of CFRP laminates whereas the last one was not strengthened with FRP and considered as a control beam. Test results showed that the addition of CFRP sheets to the tension surface of the beams demonstrated significantly improvement in stiffness and ultimate capacity of beams. The response of control and strengthened beams were compared and efficiency and effectiveness of different CFRP configurations were evaluated. It was observed that tension side bonding of CFRP sheets with U-shaped end anchorages is very efficient in flexural strengthening. The paper also highlighted the beams failure modes due to the different level of strengthening scheme.