Strengthening of RC Beams Subjected to Combined Torsion and Bending with GFRP Composites

Abstract

Beams located at the perimeter of buildings, which carry loads from slabs, joists and beams from one side of the member generates torsional forces that are transferred from the beams to the columns. The beams deficient in resisting torsion can be strengthened using Fiber-Reinforced Polymer (FRP) composites. An experimental study for the improvement of the torsional resistance of reinforced concrete beams using FRP is presented in this paper. Total 14 beams of 150mm × 150mm × 1700mm are cast. Two beams are designated as control specimens and eight beams are strengthened by Glass Fiber Reinforced Polymer (GFRP) wrapping of different configuration. All beams are subjected to combined effect of torsion and bending. A loading frame and test set up are fabricated for applying combined torsion and bending. Angle of twist at interval of torque, torque at first crack, ultimate torque are compared for control and strengthened beams.