Reducing prestress structure system before prestressed reinforcement withdrawing tension

Abstract

The invention provides a structural system for reducing prestress before tension reduction of prestressed reinforcement, which consists of a novel fixing end capable of being repeatedly assembled and disassembled and a tensioning end structural system. In the structural system, when the design value of the tensile strength of the prestressed reinforcement is reached, before reducing tensile force and removing clamping pieces, the tensile force of the prestressed reinforcement is reduced in advance, before the final tension reduction, the pulling force value of the prestressed reinforcement is reduced until the material elongation generated by the left tensile strength value is enough for successful tension reduction, thereby fully utilizing the strength design standard value of the prestressed reinforcement, improving material utilization ratio, reducing the consumption of the prestressed reinforcement, reducing the structural specification of the whole structural system including the fixing end and the tensioning end and a prestressed reinforcement pore path; the unsuccessful tension reduction and the failed repeated use of the prestressed reinforcement caused by the beyond-the-limit working pulling force of the prestressed reinforcement are avoided; and the structural system provides new technological conditions for the non-bonding after-tension method prestress structural system used for the combination and disassembly of concrete precast components to save resources and lower cost.

Description

technical field [0001] The invention relates to an untensioned construction system of unbonded post-tensioned prestressed steel bars of periodically assembled and decomposed concrete prefabricated components. Background technique [0002] At present, the prestressed structure system of the concrete prefabricated components of the combined foundation of mechanical equipment used for periodic movement (such as building tower cranes, petroleum extraction machines, geological and mine exploration machines, etc.) can be repeatedly retracted to make the prestressed steel bars reused. For the purpose of unbonded post-tensioning, the tensile design value of the prestressed steel bar is only about 40% of its standard value of tensile strength, which is still 71% of the standard value of its standard value. There is a gap of about 31%, which is another considerable resource waste and cost waste caused by technical measures to achieve the purpose of saving materials and reducing costs ...

AI Technical Summary

Problems solved by technology

[0002] At present, the prestressed structure system of the concrete prefabricated components of the combined foundation of mechanical equipment (such as building tower cranes, petroleum extraction machines, geological and mine exploration machines, etc.) for periodic mobile use can be repeatedly retracted so that the prestressed steel bars can be reused. For the purpose of unbonded post-tensioning method, the tensile design value of the prestressed steel bar is only about 40% of its standard value of tensile strength. There is a gap of about 31%, which is another considerable waste of resources and cost caused by technical measures to achieve the purpose of saving materials and reducing costs by realizing that prestressed steel bars can be reused many times

However, the existing prestressed steel back-tensioning methods and construction measures cannot realize the unrestricted use of the prestressed steel bar under the condition of ensuring the material mechanical properties of the prestressed steel bar for repeated use within the range of the remaining strength standard value (71-100%). Damaged return

The technical status quo is that either the tensile design value of the prestressed steel bar is reduced for the need of complete untensioning to realize repeated use, resulting in an increase in the amount of prestressed steel bar, and the chain of increase in the amount of steel bar causes the entire construction system including the tension end and the fixed end. The further comprehensive waste formed by the corresponding increase in the structure of the steel channel; or the strength design value of the prestressed steel bar is used to the specified limit, resulting in the retreat of the prestressed steel bar. The damage can only be a waste of one-time use; both Unavoidable waste of materials and costs

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