Bending Response of HSRC Beams Strengthened with FRP Sheets

The repair and strengthening of rc structures has become a major problem for civilengineers in the past few decades. to satisfy this problem, a previous method for the repair andstrengthening of rc beams included bonding steel plates to the inferior structure. however, bonding steelplates to concrete presents disadvantages, including corrosion of the steel/adhesive joints and the heavyweight of the material. these problems increase installation and maintenance costs. the bonding of fiberreinforced plastics (frp) to structures provides an attractive alternative to steel plates. this materialis corrosion resistant and lightweight, has a high strength-to-weight ratio and possesses nonconductiveproperties. the use of fiber reinforced plastics (frp) in repairing and strengthening rc beams has beenresearched in recent years. in particular, attaching unidirectional frp to the tension face of rc beams hasprovided an increase in the stiness and load capacity of the structure. however, due to the brittle natureof unidirectional frp, the ductility of the beam decreases. consequently, the safety of the structure iscompromised, due to the reduction in ductility. the purpose of this research is to investigate the behaviorof high strength reinforced concrete beams strengthened with frp sheets. the major test variables includedthe dierent layouts of cfrp sheets and the tensile reinforcement ratio. more particularly, change in thestrength and ductility of the beams, as the number of frp layers and tensile reinforcement bar ratios arealtered, is investigated. eight under-reinforced concrete beams were fabricated and tested to failure. withthe exception of the control beam, one or four layers of cfrp were applied to the specimens.