Double-helix-shaped large-diameter cast-in-place pile concrete cooling pipe

Abstract

The invention provides a double-helix-shaped large-diameter cast-in-place pile concrete cooling pipe. The double-helix-shaped large-diameter cast-in-place pile concrete cooling pipe aims at achievingthe effects that a large-diameter cast-in-place pile constructed in winter is effectively subjected to temperature control and maintenance, surface layer concrete of the cast-in-place pile is prevented from being subjected to early freeze injury while temperature cracks caused by the overhigh internal temperature and the overlarge temperature difference of the cast-in-place pile are avoided. The double-helix-shaped large-diameter cast-in-place pile concrete cooling pipe is composed of an external helix pipe, an internal helix pipe and a bottom connecting pipe in a constant-speed helix form, wherein the external helix pipe and the internal helix pipe are each in a cylindrical helix form. According to the temperature reduction and maintenance purposes and temperature change of the concrete of the cast-in-place pile, the temperature of the concrete of the cast-in-place pile is controlled by adopting the forms of adjusting the water temperature of cooling water, changing the water injection direction and the like, the conflicts such as freeze prevention and crack resistance encountered in winter construction of the cast-in-place pile are effectively solved, and the double-helix-shapedlarge-diameter cast-in-place pile concrete cooling pipe is a temperature control facility suitable for winter construction of the large-diameter cast-in-place pile.

Description

technical field [0001] The invention relates to a temperature control device suitable for winter construction of large-diameter cast-in-situ piles, in particular to a double-helix concrete cooling pipe for large-diameter cast-in-situ piles. Background technique [0002] Concrete is a brittle material, its tensile strength is only about one-tenth of the compressive strength, and its tensile deformation capacity is also very small. In addition, the cross-sectional size of mass concrete is large. After the concrete is poured, the internal temperature rises sharply due to the heat of hydration of the cement. In the initial stage of pouring, the elastic modulus of the concrete is small and the creep is large, and the compressive stress caused by the temperature rise does not increase. It is not large, but when the temperature drops in the future, its elastic modulus and relatively large, the creep is very small, and a considerable tensile stress will be generated under certain co...

AI Technical Summary

Problems solved by technology

[0005] Second, there is a lack of concrete curing devices and technologies suitable for large-diameter cast-in-place piles

At present, the research on the temperature control technology of large-volume concrete is mainly concentrated on structures such as concrete dams and cast-in-place caps, and there are still no relevant reports on the temperature control devices and maintenance technologies of large-diameter cast-in-place piles

However, due to the closed soil environment and structural form of the large-diameter pile foundation, the plum blossom-type encrypted cooling water pipe device widely used at present cannot be used for the cast-in-place pile foundation; the concrete surface insulation technology such as foam plastic board cannot be used for the cast-in-situ pile. At the same time, due to the limitation of the low temperature environment, the pre-cooled concrete pouring technology is not suitable for the construction of cast-in-place piles in winter

[0006] Third, the large-diameter cast-in-situ pile is located in a closed soil environment with poor thermal conductivity, and the heat dissipates slowly, and the heat storage method superimposes the concrete hydration heat, resulting in extremely high internal temperature of the concrete pouring body, which directly contacts the surface of the pile body with the external low temperature The permafrost environment produces a huge temperature difference between inside and outside

The construction of large-diameter cast-in-situ piles in winter, especially the piles poured by the heat storage method, faces extremely high core concrete temperature treatment in the early stage of pouring, and faces low temperature curing on the surface of the poured body in the later maintenance process. At present, there is still no way to meet the above two conditions. Maintenance devices and techniques for each process

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