CALCULATION ON BEARING CAPACITY OF 7075 HIGH-STRENGTH ALUMINUM ALLOY TUBULAR CONFINED CONCRETE COLUMN UNDER AXIAL COMPRESSION

High-strength aluminum alloy has great application prospects in large-scale infrastructure projects due to its corrosion resistance, high strength and good ductility. In this paper, based on the comparative analysis of the commonly used calculation theory of bearing capacity of confined concrete columns under axial compression, the calculation method of bearing capacity of aluminum alloy tubular confined concrete columns was proposed. Then,the finite element model of 7075 high-strength aluminum alloy tubular confined concrete column under axial compression was established by ABAQUS. The finite element simulation results were compared with the calculation results based on the existing experimental results of aluminum alloy tubular confined concrete column. The results showed that the Eurocode 4 did not take the restraint factor of steel pipe on concrete into account, which led to the calculated result biased towards a safe value. The "unified theory" rectangular steel tube calculation formula did not suitable for aluminum alloy confined concrete rectangular column. According to Code for Design of Steel-Concrete composite Structure (DL/T 5085-1999) and Technical specifications for Early-Strength Model Composite Structure Used for Nary Port Emergency Repair in Wartime (GJB 4142-2000), however, the obtained bearing capacity of aluminum alloy tubular confined concrete column was only about 4 percent higher than the finite element simulation value which indicated the finite element simulation results were consistent with the test results. Finally, based on DL/T code and GJB code while treating the constraint effect coefficient as the parameter, the calculation method of axial compressive capacity of concrete column restrained by aluminum alloy tube was proposed.