Experimental Study On The Shear Capacity Of Concrete Beams With FRP Stirrups

The reinforced concrete structure is the main structure form in the civil engineering, but the decrease in the durability and the lost in the use of the structure caused by the steel corrosion has become a serious problem in the concrete structures. To use FRP bars substitute steel bars is an effective solution in the structure design. FRP bars has the advantages of light weight, high strength and corrosion resistance, which has become a new type of structural materials., and can good enough to solove the increasingly serious reinforced corrosion problems in the concrete structure.A large number of phenomena, which is the corrosion of the concrete structures show that the corrosion of the structure most likely occur in the corner, FRP stirrups can be used instead of the reinforced in order to improve its durability, in which way longitudinal reinforcement can be surrounded by FRP stirrups around the corner, so the FRP stirrups can protect the longitudinal reinforcement together with concrete. But FRP bars is different from the steel bars, it is brittle material, shows the performance of the linear elastic until extraction, does not have the yield platform, and has low modulus of elasticity. So the member with these materials will have brittle damage. If we use the FRP materials as the composite members or the structural reinforcement directly, the limit state、design method and the reliability of the structure must be reconsidered, the rational design method should be adopted for its performance. Based on this, the experimental research of the shear behavior of the reinforced concrete beams with the FRP stirrups is carried out.The main work of this paper is to study the shear behavior of the reinforced concrete beam with the GFRP stirrups. Through the experimental study of six rectangular cross-section simply supported concrete beams, which are under the concentrated loads, the deformation behavior、the development of the diagonal cracks、the variation of the stirrup strain and the failure modes of the beams with the GFRP stirrups are analyzed, the destruction features of the GFRP bars is found under sheared beam. The shear span ratio and stirrup ratio which affect the deformation behavior、the development of the diagonal cracks and the failure modes of the experimental beams are researched. Through the analysis the test data, the truss model is adopted, which is the same with the one adopted by Chinese specification for calculating reinforced concrete beam bearing capacity. Through revising the beam shear equation in our concrete specification, a concrete beam with FRP stirrups shear equation is proposed, which is joined with our specification. And some reference is provided about established the calculation of the concrete shear capacity later.