Examining Alternative Strengthening Method for RC T-Beams Using CFRP and UHPC

摘要

Flexural strengthening of Reinforced Concrete (RC) beams using fiber reinforced polymer (FRP) has become a common practice in the construction industry. Such strengthening is typically performed by attaching FRP laminates to the tension side of RC beams. In many occasions reaching the tension side of the beam can be a major challenge due to existing ducts as in buildings or the need of large scaffolds underneath the beam as in bridges. This challenge makes FRP strengthening an expensive alternative. In this paper, we suggest an alternative flexural strengthening method using a composite system made of Ultra High-Performance Concrete (UHPC) and Carbon Fiber Reinforced Polymer (CFRP) laminates for RC beams without reaching the tension side of the beam. In this technique, the accessible cover of the RC T-beam is removed, the CFRP laminates are attached to top side of the beam then a thin UHPC overlay is cast over the FRP. We show that the combination of UHPC and FRP allows the FRP to act as additional tensile reinforcement and increase the flexural capacity of the RC T-beams. The proposed method might be effective for shallow to medium RC T-beams specifically T-beams with very wide flange.