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Journal of Polymer & Composites Original Research

Experimental and Numerical Assessment of Flexural Shear Behavior of RC Beams Enhanced using Hybrid CFRP–GFRP U-Wrap System

  1. Kallamadi Naveen Reddy , Department of Civil Engineering, Bharath Institute of Higher Education and Research, Chennai
  2. M. Hema Priya Department of Civil Engineering, Bharath Institute of Higher Education and Research, Chennai
  3. J. Faney Department of Civil Engineering, Bharath Institute of Higher Education and Research, Chennai

Abstract

This study examines the Reinforced Concrete beams strengthened in Flexural-shear using a hybrid Fibre Reinforced Polymer (FRP) system that combines carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP) in a U-wrap configuration. Six beams totally were made and the results were tested under 4 point bending moment using LVDT, in which three beams were of control beams without strengthening and another three externally wrapped using hybrid CFRP-GFRP U-wraps. The beams were built using M30 grade concrete, 2 x 10 mm tensile bars, and 2 x 8 mm compression bars. The hybrid strengthening configuration featured an initial layer of GFRP, followed by an outer layer of CFRP bonded using Araldite LY556 epoxy and Hardener HY951. The testing results demonstrate a considerable increase in load carrying capability, stiffness, and crack control when compared to unstrengthened beams. The flexural response of both control and strengthened beams was simulated using finite element modeling with ANSYS Mechanical. With respect to final load, deflection patterns, and stress-strain distribution, the numerical results were nearly identical to the experimental findings. The hybrid FRP wrapping system significantly improved flexural performance, including increased ductility and delayed crack propagation. The study shows that the CFRP-GFRP hybrid U-wrap system is an efficient and cost-effective alternative to single-type FRP reinforcement in RC beam retrofitting applications.

Keywords

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