Experimental Investigation Of GFRP Strengthened Rc Beams Under Pure Torsion

Abstract

Fiber Reinforced Polymer (FRP) as an external reinforcement is used extensively for axial, flexural and shear strengthening in structural systems. The strengthening of members subjected to torsion is recently being explored. The loading mechanism of beams located at the perimeter of buildings which carry loads from slabs, joists and beams from one side of the member generates torsion that are transferred from the beams to the columns. In this paper an experimental investigation on the improvement of the torsional resistance of reinforced concrete beams using Glass Fiber Reinforced Polymer (GFRP) is presented. Total ten beams of dimension 150mm × 150mm × 1300mm are cast. Two beams are designated as control specimen and eight beams are strengthened by GFRP wrapping of different configuration. All beams are subjected to pure torsion using specially fabricated support mechanism and universal testing machine. Measurements of angle of twist at regular interval of torque, torsion at first crack, and ultimate torque, are obtained for all specimens. Results of different wrapping configurations are compared and the effective GFRP wrapping configuration is suggested.