Flexural Behavior of Rc Beams Strengthened with Hybrid C-Pet Frp Laminates

Abstract

This paper presents an experimental study on the flexural performance of reinforced concrete (RC) beams externally bonded with hybrid fiber-reinforced polymer (FRP) laminates made of carbon and polyethylene terephthalate (PET) fibers. Four-point bending tests were carried out on ten beam specimens to investigate the effects of the stacking sequence and the elastic modulus of hybrid carbon-PET FRP laminates on the flexural performance of the strengthened specimens. The failure modes, load-bearing capacities, displacement ductility of the specimens and strain distribution in the FRP laminates are examined and discussed. The test results show that the load-carrying capacities of the FRP-strengthened specimens are significantly increased accompanying by reduced ductility. The beams strengthened with the PC and CPC stacking sequences have achieved higher peak loads and ductility than their counterparts strengthened with two- and three-layer hybrid FRP laminates. The calculation methods specified in ACI 440.2R, CNR DT 200 R1 and GB 50608 are used to predict the flexural strengths of the strengthened RC beams, and their accuracy and reliability are evaluated through the comparisons between theoretical predictions and experimental results.

Keywords: PET, CFRP, hybrid FRP laminates, flexural reinforcement, Reinforced concrete, beams