Research On Mechanical Behaviors Of Hybrid FRP Box-Concrete Slab Beams

In recent years, to solve the increasingly serious problem of corrosion of steel, FRP materials have been widely used in the bridge structure, this kind of material, according to its structure, can be divided into Complete FRP and FRP and Concrete Composite Structure. Hybrid FRP Box-Concrete Slab Beams is a new composite structure which evolved from the combination of FRP and Concrete Structures. It contains GFRP box girder, bottom-pasted CFRP and partly-filled concrete structure. As the Internal buckling of GFRP box girder on the compressed and sheared sections of the FRP Box Wall which is limited due to the concrete structure, the strength upon localized buckling of the structure has greatly increased, therefore, Maybe the greater use of FRP Strength; Most of the Concrete was filled in Compression Zone of the beams, And was restricted by the FRP Box Wall. Improved the mechanical properties and better able to give full play to the advantages of its good compression performance; Not The CFRP's role is to serve as a pre-stressed to reinforcement the stiffness and to reduce the beams deformation, but as a failure warning of the FRP Box Beams. Which, Hybrid FRP Box-Concrete Slab Beams equally traditional high strength, stiffness, and ductility, and construction of the advantages of convenience.In this paper, the mechanical behaviors of Hybrid FRP Box-Concrete Slab Beams are studied by the methods of theory analysis and numerical evaluation systematically establishes the theoretical calculating system of the mechanical behaviors of Hybrid FRP Box-Concrete Slab Beams. The main achievements of this paper are as followings:In the basis of the results of previous studies, I presented the thoughts of the Hybrid FRP Box-Concrete Slab Beams cross-section designs. Examples of domestic and foreign Projects from The FRP box beams have been cost-effective analysis, the analysis pointed out:From the whole life cycle of a bridge, FRP and Concrete Composite Structure bridge costs less than the same size of the steel bridge, in some cases even lower in reinforced concrete bridge. In this paper, the T-shaped and rectangular Hybrid FRP Box-Concrete Slab Beams's Cross-section geometric characteristics, elastic flexural capacity, the limits of flexural capacity and shear strength were studied and gave the corresponding formulas;Derived the formula for calculating of the Hybrid FRP Box-Concrete Slab Beams under the influence of the slip deformations, the interface shear stress and longitudinal stress, and examples of different connection stiffness, cross-section of different sizes and different load cases, shear stress and axial pressure distribution,The results show that the formulas are in good agreement with the numerical examples.Finally, Carries on the elastic-plastic analysis with the banding allocation method to the Hybrid FRP Box-Concrete Slab Beams's stress entire process, Has established the nonlinear analysis procedure, and obtained the FRP bending moment-curvature, the load-deformation relations curve, Compared the two:at the bottom of the FRP box beam paste CFRP with higher strength, greater stiffness and better ductility, the whole process of force to be divided into flexible clear stage, elastic-plastic stage and destruction stages.