Study On Flexural Performance Of Unbonded Partially Prestressed Concrete Simply Supported Beams With FRP Tendons

FRP reinforcement for normal concrete structure, because of its light weight, corrosion resistance, resistance to fatigue and many other features, there will be significant damage of over bars, unsafe and difficult to give full play to material properties, it is because the flexibility of FRP reinforcement low modulus, a linear elastic stress-strain relation, making a big difference between prestressed FRP reinforced concrete members and reinforced concrete members. so it is necessary to study the FRP tendons of prestressed concrete structures and mechanical properties calculation method. Based on the previous theoretical and experimental study on the prestressed FRP reinforced concrete,the flexural members were analyzed, mainly for the following areas:(1) Three simply supported prestressed CFRP reinforced concrete beams selected in the literature under third point loading for the whole process simulation of nonlinear finite element analysis are analyzed, the modeling method, selecting unit selection, the definition of material constitutive relation and solution methods were specified. The main results obtained with ultimate strength, deflection, steel stress, crack and so on. Finally, a comparsion was made between the analyzd results and the experimental results, and the reliability of finite element models was obtained, providing the basis for the theoretical analysis.(2) form the domestic and foreign FRP prestressed concrete beams reinforced part of the research results of the inspection analysis, and experimental literature in this study and selected non-linear finite element analysis, the relevant factors were studied about partially prestressed FRP reinforced concrete beams,which include concrete strength, prestressing degree, integrated steel reinforcement index, and the configuration of the compression zone and so on. The tests showed that the configuration CFRP tendons of prestressed concrete beams, the use of partially prestressed form can significantly improve the mechanical properties of the beam. Within a certain range of concrete strength increased is conducive to the improvement of mechanical properties of the whole beam.