Large-span concrete beam construction method based on unbonded steel strand prestress post-tensioning

Abstract

A large-span concrete beam construction method based on unbonded steel strand prestress post-tensioning. The method includes: preparing, feeding steel strands, laying steel strands, mounting end nodes, casting and compacting concrete and maintaining the same, prestress tensioning and end processing. The method has the advantages that when prestress is applied to a floor structure, evident application effect in cast-in-situ beam plate and prefabricated beam type structure is achieved, building rigidity and integrity are increased, building shock resistance is increased, design of an ultra large-span floor system is possible, room arrangement is flexible, application functions of buildings can be improved, project building cost is lowered, steel can be saved by 30-40%, structure weight is reduced, investment cost is lowered, evident comprehensive technological, economical and social benefits are achieved, and the method is applicable to unbonded prestress construction of industrial and civil building large room plate-wall structures and reinforcing of bridges, plane runways, large foundations and retaining walls.

Description

technical field [0001] The invention relates to a construction method related to the international patent classification E04B building structure, especially a large-span concrete beam construction method based on prestressed post-tensioning of unbonded steel strands. Background technique [0002] In the prior art, the unbonded prestressed construction method is seldom disclosed. For example, the patent application number 201210305921 discloses a post-tensioned prestressed anchoring construction method for a poured concrete structure with bonding. The underground structure is formed by making and placing the steel cage, the check valve at the end of the steel conduit, and the cast-in-place concrete. After it is formed and matured, the prestressed steel strand is lowered to the designed connection position, and the steel strand is completed by special equipment. Tensioning, end anchoring and tensioning, and grouting in the steel conduit complete the protection of the prestress...

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Problems solved by technology

[0003] As another example, Chinese Patent Application No. 201010298332 relates to a post-tensioned prestressed anti-pull cast-in-place pile without skeleton and bond and its construction method, which uses unbonded steel strands instead of ordinary threaded steel bars in traditional cast-in-place piles, and through non-bonded The lower end of the bonded steel strand is fixedly connected to the bottom anchor plate at the bottom of the pile concrete, and the upper end of the unbonded steel strand is fixed to the top anchor plate at the top of the pile concrete through extrusion anchors, and the vibrating tendon inserter is used as a temporary anchor. The skeleton is inserted into the concrete of the pile body, and a pre-tension force is applied to the unbonded steel strand, which solves the problem that the concrete of the cast-in-situ pile body is prone to cracks under the tensile state, which affects the durability of the pile body, and the cost of ordinary uplift piles The problem of high steel consumption and large amount

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