A pre-tensioned prefabricated I-beam and its construction method

Abstract

The invention discloses a pre-tensioning method prefabricated I-shaped beam and a construction method thereof. The construction method comprises the steps of steel strand tensioning and releasing, steel reinforcement framework binding and hoisting, concrete pouring and maintenance and I-shaped beam form removal. According to the method, effective prestress is guaranteed by collecting and controlling the tensile stress of the steel strands, and the shrinkage creep model of the pre-tensioning method I-shaped beam is established according to the actual attributes of poured concrete and a water reducing agent, so that the construction scheme and the structural design are optimized; the prestress is transmitted according to the bonding force of the steel strand and the poured concrete; in the elastic stage of the whole structure, the prestress is transmitted into the concrete structure through a certain transmission length; meanwhile, the steel bundles formed by the steel strands are free of frictional resistance loss along the way in the prefabricating process, so that the engineering quality is guaranteed, and the problems that the overall structural strength of the I-shaped beam is greatly reduced due to the fact that the prestress friction of the post-tensioned prefabricated part is too large, the stress ribs are prone to retraction and the prestress loss is too large are solved.

Description

technical field [0001] The invention relates to the technical field of road and bridge structures, in particular to a pre-tensioned prefabricated I-beam and a construction method thereof. Background technique [0002] The three bridge structures that have been used the longest and most widely in my country's expressways are prefabricated hollow slabs, prefabricated T-beams and prefabricated box girders, which have made great contributions to the rapid development of expressways and the transportation industry. . [0003] With the gradual pursuit of short, flat and fast construction period goals for expressways, pre-tensioned prefabricated I-beams need to be involved. However, there is still excessive prefabricated friction in the prefabrication process of existing pre-tensioned prefabricated I-beams. , The tendons are easy to retract and the prestress loss is too large, which leads to a great reduction in the overall structural strength of the I-beam; and there is also the p...

AI Technical Summary

Problems solved by technology

[0008] (1) How to use an effective method to solve the problems of excessive prefabrication friction, easy retraction of stress tendons and excessive prestress loss in the prefabrication process, so as to avoid the overall structural strength of the I-beam from being greatly reduced;

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