Production method of prestress concrete filled steel tube

Abstract

The invention provides a production method of a prestress concrete filled steel tube. A vent hole is arranged at one end of the steel tube, and a pouring pressurization port is arranged at the other end of the steel tube. Concrete is poured into the steel tube through the pouring pressurization port till the concrete bursts out from the vent hole, after pouring, a vent hole valve is closed, and a concrete pump is stopped. Slurry is injected into the steel tube continuously through a pressurizing device, injection is stopped when the pressure in the steel tube is 1-1.2 times as large as target compressive prestress, stabilization is conducted for half an hour, and a prestress exerting process is finished. After the concrete strength in the steel tube is 1.5 times higher than the target compressive prestress, the pressurizing device is detached, the pouring pressurizing port is closed immediately, and the concrete filled steel tube with radial prestress is formed. By means of the production method, exerting of quantification prestress is facilitated, compressive prestress can be controlled conveniently, evenness of exerted prestress is improved, the axial compressive strength of concrete is improved, and compressive strength and other performances of the prestress concrete filled steel tube are improved.

Description

technical field [0001] The invention relates to a manufacturing technology of structural components in construction engineering, in particular to a production method of prestressed steel pipe concrete. Background technique [0002] Concrete-filled steel tubes comprehensively utilize the material properties of steel and concrete to make them work together. They have the characteristics of high strength, yield resistance, large elastic modulus, and good plasticity. The compressive strength can reach about 2 times that of steel tubes and concrete respectively. Therefore, its application in construction engineering is increasing day by day. If prestress is applied to the steel pipe concrete, so that the steel pipe is in a state of circumferential tension and the concrete is in a state of radial compression, its strength and other properties will be further improved. [0003] There are usually two prestressing methods for prestressed steel pipe concrete members: (1) The first me...

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Problems solved by technology

[0004] Method 1 adopts the traditional post-tensioned concrete construction technology, and applies pre-loading pressure after the concrete is completely hardened. Due to the limitation of the strength and deformation capacity of the concrete itself, the pre-stressing force of the steel tube wall is also limited, and the hardened The concrete surface and the inner side of the steel pipe wall do not fit perfectly, resulting in uneven prestress of the steel pipe wall under circumferential tension

In addition, when the component is long or has a certain curve radian, the prestress friction loss caused by method 1 during the construction process is relatively large, and the construction operation is inconvenient

[0005] The second method uses the volume expansion of the concrete hardening process to achieve the same effect as the first method, but the micro-expansion of the concrete causes the prestress of the circumferential tension of the steel pipe wall to be very limited, and the expansion of the concrete material is also non-uniform in all directions , resulting in uneven prestress of the steel pipe wall under circumferential tension

[0006] More importantly, these two production methods cannot directly determine the size of the applied prestress, and cannot conveniently apply quantitative prestress

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