Mechanical Behaviors Study Of GFRP Tube Filled With Steel-reinforced High-strength Concrete Composite Members

In recent years, Fiber Reinforced Polymer, shorten as FRP, is widely used in the field of civil engineering for its advantages in high-strength, high efficiency and corrosion resistance. It is popular used not only in the structure reinforcement and reinstatement of the concrete structure, but also in the new constructed structure in some developed countries. However, the research and experiment of FRP confined concrete started late in China and is fallen behind by America, Japan and many European countries. There is few research of FRP tube which is being used as the structure material for direct loading, confined concrete to reducing the component section in China. Therefore, experimental study, theoretical analysis and calculation simulating are integrated in this article for the research of the axial compression, eccentric compression and flexural behavior of the GFRP tube filled with steel-reinforced high-strength concrete composite members. The compression and bending and flexural behavior of FRP cloth steel-reinforced high-strength concrete composite members.The article mainly covers the following fields:Experimental study on composite columns axial compression of GFRP tube filled with steel-reinforced high-strength concrete and GFRP tube filled with high-strength concrete. The research on mechanism and failure mode, analysis on composite columns’bearing capacity, deformation, strain distribution of GFRP and steel are studied through experiments; comparison and analysis on the GFRP confined concrete component in different winding angles of fiber, thickness of pipe, loading situation, concrete strength and steel or non-steel content are carried out. The experimental results showed that the bearing compressive capacity of composite columns increase with the thickness increase of GFRP tube%the strength increase of concrete and GFRP tube filled with steel-reinforced high-strength concrete, the bearing compressive capacity of composite columns increase with the decrease of the fiber tangle angle. Calculation formula of composite short column’s bearing capacity are pointed out by superposition method and ultimate balance method; Experimental study on the composite column’s eccentric compression of GFRP tube filled with steel-reinforced high-strength concrete, bearing capacity, failure mode, deformation, strain distribution of GFRP and steel is analyzed; comparison and analysis on different winding angles of fiber, thickness of pipe, slenderness ratio, eccentricity and loading axis (major and minor axis) etal parameters. The experimental results showed that the bearing compressive capacity of composite columns increase with the thickness increase of GFRP tube and load on major axis, the bearing compressive capacity of composite columns increase with the decrease of eccentricity and loading axis、the slenderness ratio and the fiber tangle angle. Calculation formula of bearing capacity is pointed out, which is suitable for different failure modes of composite column; Nonlinear full-process analysis to eccentric compression component is carried out through program composition;Experimental study on flexural behavior of the GFRP tube filled with steel-reinforced high-strength concrete. The analysis on the influence of different winding angles of fiber and thickness of pipe to the bearing capacity of composite component is studied through experiments. The experimental results showed that the bending resistance bearing capacity of flexural component increase with the thickness increase of GFRP tube, the bearing compressive capacity of flexural component increase with the decrease of the fiber tangle angle. Calculation formula of bending resistance bearing capacity is pointed out, which is suitable for different failure modes of flexural component; Nonlinear full-process analysis to this kind of flexural component is carried out through fiber model method;Analyzing on bearing capacity of the flexural and compression and bending member of FRP cloth steel-reinforced high-strength concrete through theoretical analysis and calculation simulating. Calculation formula of bearing capacity of FRP cloth steel-reinforced high-strength concrete flexural member and compression and bending member is pointed out; The existed FRP confined high-strength concrete stress-strain relation is modified; Nonlinear full-process analysis to flexural component is carried out through program composition; by referring to the characteristic and advantage of cusp catastrophe model, a cusp catastrophe model of bearing capacity of FRP confined concrete eccentric compression component under long-term load is established.