GFRP Reinforced RC Deep Beam with Multiple Web Openings

Abstract

Deep beams are members with clear spans to depth ratio equal or less than four times the overall depth. Reinforced Concrete (RC) deep beams are used as load-distributing structural elements such as transfer girders, pile caps, foundation walls and offshore structures. Due to some structural and aesthetical aspects, provision of openings with square, rectangular and circular shapes are provided in the beams. These openings are made mainly for providing conduits and ducts. These provisions are mainly used for the reduction of space in high rise buildings. In offshore construction, the corrosion of reinforcement is the major threat to the structural integrity of the structure. To overcome this corrosion problem, Fibre Reinforced Polymer (FRP) reinforcements are employed under such extreme situations. The non-corrosive nature of FRP reinforcements enhances the serviceability of the structures. The present study was aimed to determine the ultimate load-carrying capacity, ultimate shear-carrying capacity and crack propagation of deep beams reinforced internally with Glass Fibre Reinforced Polymer (GFRP) reinforcements with multiple circular web openings. The deep beams of size 1100 mm × 150 mm × 450 mm were cast. Two different reinforcement ratios of 0.50 and 0.84% provided at the bottom with top reinforcement of 0.33%. A total of six beams with multiple circular web openings were cast, out of which four beams with GFRP and remaining two beams cast with conventional Steel reinforcement. The ultimate load-carrying capacity, ultimate shear-carrying capacity, number of cracks, mode of crack formation, and direction of crack propagations were observed. The theoretical and analytical predictions were carried out for load- and shear-carrying capacities. These results were compared with experimental results.