Experimental Study On FRP Confined High Strength Concrete Filled Steel Tube Stub Columns Subjected To Axial Compression

In order to better adapt to the functional requirements of the modern high-rise, super high-rise structure, composite structures with a smaller cross-section, high capacity and better ductility are appearing. The FRP confined high strength concrete filled steel tube stub columns subjected to axial compression is made up of CFT and FRP confined high strength concrete. The research on FRP confined high strength concrete filled steel tube stub columns subjected to axial compression has been carried out initially, which restricts its application in engineering. The experimental study on FRP confined high strength concrete filled steel tube stub columns subjected to axial compression contributes to promotion and application in high-rise buildings, which is meaningful of theoretical study and practical engineering.Six FRP confined high strength concrete filled steel tube stub columns and one common high strength concrete filled steel tube stub column are tested under axial compression. The outlines of this research are as follows:(1) Based on FRP tube diameter and FRP tube wall thickness, an experimental study on FRP confined high strength concrete filled steel tube stub columns under axial compression is carried out. Experimental research shows that the axial bearing capacity of FRP confined high strength concrete filled steel tube stub columns is higher than common high strength concrete filled steel tube stub columns and the ductility of FRP confined high strength concrete filled steel tube stub columns is better than common high strength concrete filled steel tube stub columns.(2) The effects of the parameters including FRP tube diameter and FRP tube wall thickness are studied, on the ultimate bearing capacity, failure modes, load-strain curves and ductility, resulting in calculated method for the ultimate capacity of FRP confined high strength concrete filled steel tube stub columns. Experimental results show that the axial bearing capacity of FRP confined high strength concrete filled steel tube stub columns increases with the increase of FRP wall thickness when the other parameters are the same, the axial bearing capacity of FRP confined high strength concrete filled steel tube stub columns increases with the increase of FRP diameter when the other parameters are the same The effects of the material on the ultimate bearing capacity is not valid when the tensile stiffness of FRP tube are the same. But it can improve the ductility of FRP confined high strength concrete filled steel tube stub columns to use a large fracture strain FRP tube.(3) Based on the experimental study, the working principle of FRP confined high strength concrete filled steel tube stub columns is analyzed. Finally, a calculation method for axial bearing capacity of FRP confined high strength concrete filled steel tube stub columns is proposed, which is appropriate for practical engineering.