Concrete filled steel tubular structure internally provided with composite tubes and seawater sea sand concrete

Abstract

A concrete filled steel tubular structure internally provided with composite tubes and seawater sea sand concrete. The concrete filled steel tubular structure comprises a steel tube, common concrete,the composite tubes and the seawater sea sand concrete. More than one composite tube is arranged in the section of the steel tube, the axes of the composite tubes are parallel to the axis of the steeltube, the internal parts of the sections of the composite tubes are filled with the seawater sea sand concrete, the gaps between the composite tubes and the steel tube are filled with the common concrete, the seawater sea sand concrete and the common concrete are separated by the composite tubes, protection is provided for resisting chloride ion corrosion, and meanwhile possibility is provided for arranging steel bars in the outer common concrete. The composite tubes and the steel tube provide the inner constraint and the outer constraint for the seawater sea sand concrete, the mechanical performance of the seawater sea sand concrete is greatly improved, seawater sea sand resource utilization is achieved while the application effect of the normal common concrete is reached, and broad prospects are achieved.

Description

technical field [0001] The invention belongs to the field of civil engineering, and relates to a composite steel pipe concrete member, in particular to a steel pipe concrete member with built-in composite pipe seawater sea sand concrete. Background technique [0002] Concrete-filled steel tubes have the advantages of high strength, light weight, large section bending stiffness, corrosion resistance, and good fire performance. At the same time, they can be used as a formwork for internal concrete and have good mechanical properties. be widely used. However, with the development of the times, resources are becoming more and more scarce, especially building river sand is becoming more and more scarce, and sea sand is rich in resources, but sea sand has a high chloride ion content and is highly corrosive to steel, so it cannot be used in steel pipe concrete, etc. Simple application in traditional structures. At the same time, CFST is prone to local buckling under load, which r...

AI Technical Summary

Problems solved by technology

For example, Chinese Patent No. "201910036888.7" discloses a seawater sea-sand concrete column. This structure is composed of FRP-steel composite bars, polyethylene pipes and seawater sea-sand concrete. Several FRP-steel composite bars are vertically arranged on the polyethylene In the pipe, the polyethylene pipe constrains the seawater sea sand concrete filled in the pipe. This method uses FRP-steel composite bars as structural reinforcement to avoid the corrosion of steel bars. However, FRP-steel composite bars have application problems such as bending and connection. Only Relying on polyethylene pipes to restrain the outer side, the effect is limited, and at the same time, the fire resistance and high temperature resistance are poor

In order to improve the mechanical performance of steel pipe concrete, Chinese Patent No. "201811400216.1" announced a steel pipe concrete column. This structure includes inner steel pipes, outer steel pipes, connecting plates between inner and outer steel pipes, and concrete between inner and outer steel pipes. The load-bearing capacity of the structure is improved, but the existence of the connecting plate increases the self-weight and material consumption of the structure, which is not conducive to saving costs and construction operations. Due to the corrosion of steel pipes, it is not suitable for the utilization of sea sand resources; another example is the Chinese patent "201810706163 .X” announced a new type of reinforced hollow steel pipe high-strength concrete column, including a steel pipe and a circular prestressed high-strength concrete pipe column placed inside it and concrete filled between the two. This structure strengthens the structure. Integrity improves the bearing capacity, but the extensive use of high-strength concrete and steel bars greatly increases the cost, and is also not suitable for the utilization of sea sand resources

[0004] To sum up, the existing concrete-filled steel pipe structures still lack an effective way to directly utilize sea sand resources due to the corrosion of steel pipes by chloride ions.

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