Structural Performance of Concrete Beams Reinforced with CFRP Rods or Hybrid Reinforcement

Abstract

Fiber Reinforced Polymer (FRP) rods; such as Carbon Fiber Reinforced Polymer rods (CFRP), are becoming the new wave of the future as a main reinforcement in concrete structures. Beams reinforced with this reinforcement had a reduction in ductility and stiffness. To improve the structural performance of such beams hybrid reinforcement; i.e. a combination of steel bars and CFRP rods have been proposed. This experimental study aims to throw a light on the flexural behavior of concrete beams reinforced with CFRP rods only and hybrid reinforcement. Eighteen concrete beams reinforced with different types and ratios of reinforcement (steel bars, CFRP rods or hybrid) were tested under mid span load up to failure. Pattern, width and spacing of cracks, modes of failure were observed, cracking and ultimate loads were recorded, deflections, and strains were measured. A comprehensive discussion for the obtained results was undertaken. Cracking load, ultimate load, mid span deflection and crack width for the tested beams were also theoretically predicted. A comparison between the predicted values with the corresponding experimental results was also given. An adequate level of ductility and stiffness in hybrid reinforced members was observed. Finally the conclusions and recommendations that are useful for the structural engineers in this concern are drawn.