Study On Shear Behavior Of Prestressed T Concrete Beam Reinforced With CFRP Stirrups

Prestressed RC structures are widely used in all kinds of structural engineering, as thecorrosion of rebar is becoming more and more serious, corrosion resistant materials arisessubsequently. Fiber reinforced materials (FRP) is just one of which has developed rapidly.CFRP tendons have some special characteristics, such as: light weight, high strength, smallerelastic modulus than steel bars, linear elasticity without yield point. Current research mainlyconcentrate on the flexural performance as the FRP tendons used a longitudinal reinforcement.While the shear performance of FRP stirrups is rarely researched. In order to promote thedesign and application of pure FRP reinforcement structure, it is necessary to research theshear behavior of beams reinforced with FRP stirrups. This paper discusses the shear behaviorof prestressed concrete beam reinforced with CFRP stirrups by establishing a finite elementmodel with ANSYS. The main work I do is as follows:I summarized the composition, classification, production techniques of FRP tendons andits basic performance. And I sorted the research progress of shear performance of FRPreinforced concrete beam. A brief introduction of the classic theory to estimate shear capacityof RC beam is given, and there are also two shear capacity models suitable for FRP reinforcedbeams putting forward in recent years.To verify the reliability of the finite element analysis, a model is established by ANSYSto imitate an experiment done by other researcher. Comparing the results of ANSYS andexperiment,they coincide with each other well.It proves that I establish an appropriatemodel,choose the proper unit type and find a right loading way.Then nineteen models ofprestressed beams of T shape section which is reinforced with CFRP stirrups are established.These beams are divided into five groups,to observe how shear span ratio,stirrup spacing,concrete strength,effective prestress,flange width influence the shear capacity and the memberdeformation performance.The shear capacity of the prestressed beam reinforced with CFRP stirrups is calculatedaccording to Chinese、American and Canadian standard formulas. And the results calculatedby formulas and finite element analysis are compared. This paper analyses the feature of theseformulas. According to the related theories and combining with the finite element analysisresults, a shearing capacity formula of prestressed beam reinforced with CFRP stirrups isproposed and recommended.In order to satisfy the requirement of normal service condition, the inclined crack widthshould be controlled under a limited value. This paper introduces diagonal crack widthcalculation mode of RC beam, and it can be generalized to FRP structures by changing someparameters.The formula proposes a way to determine the strength of FRP stirrups.