Construction method of prefabricated beam hogging moment tensioning groove

Abstract

The invention discloses a construction method of a prefabricated beam hogging moment tensioning groove. The construction method comprises the following steps that 1, a hogging moment tooth plate steelreinforcement framework is welded and formed; 2, a hogging moment tensioning groove formwork is installed; 3, the hogging moment tooth plate steel reinforcement framework and an anchorage device areinstalled and located; 4, a corrugated pipe is installed; and 5, concrete is poured, wherein after installing of a top plate steel bar is completed, a gap is reserved in the formwork for blocking, theconcrete is used for carrying out one-time pouring and forming from the middle to the two ends, in the pouring process, attention is paid to that pouring is carried out on a tooth plate firstly and then on a top plate, vibrating of the intensive portion of the steel bar is reinforced, and after the concrete is subjected to later-period preserving, the prefabricated beam hogging moment tensioninggroove is obtained. According to the construction method, locating precision of the anchorage device and the corrugated pipe in the hogging moment tensioning groove in the prefabricating process of abeam body can be improved effectively, the probability that the concrete on the top plate is pulled and cracked in the hogging moment tensioning construction process can be reduced, channeling blocking of the corrugated pipe is reduced, steel strands can be threaded smoothly, and the method has high market popularization value.

Description

【Technical field】 [0001] The invention belongs to the construction field of tension grooves, in particular to a construction method of prefabricated beam negative moment tension grooves. 【Background technique】 [0002] Simply supported first and then continuous girder bridges have the characteristics of reasonable force, convenient construction, etc., and the construction technology is relatively mature, but it is easy to ignore the construction quality control issues, especially the construction quality control of the negative moment area. Good negative moment construction quality is very important for It is of great significance to ensure the quality and safety performance of bridges. Since the negative moment construction is carried out after the completion of the on-site girder erection, the construction quality of the negative moment tension notch is easily overlooked by the technicians and workers of the prefabricated beam field, so that the construction quality contro...

AI Technical Summary

Problems solved by technology

Since the negative moment construction is carried out after the completion of the on-site girder erection, the construction quality of the negative moment tension notch is easily overlooked by the technicians and workers of the prefabricated beam field, so that the construction quality control is relatively poor. During on-site construction, the following problems generally exist in negative moment construction: ①The flat corrugated pipes on the top plate reserved during the prefabrication of prefabricated beams cannot be connected smoothly, and staggered platforms and broken lines are easy to occur at the joints, resulting in difficulties in threading steel strands and tension. The friction coefficient during tension is too large, the elongation of prestressed tension bars is insufficient, and it is difficult to take effective remedial measures for these problems; ②The roof concrete is cracked and pulled up when the steel strand with negative bending moment is stretched; ③ The clogging of the bellows leads to unsmooth grouting and not fullness

These problems closely affect the overall quality of the bridge, greatly reducing the durability, stability and safety of the bridge

[0003] The problems that occur at the negative moment construction site are often caused by the poor construction quality control of the negative moment tension notch during beam prefabrication

The main points are as follows: ①The positioning of the negative moment anchors and bellows is not accurate when the beam is prefabricated, which may easily cause the corresponding two bellows to fail to connect; ②The number of reinforcing ribs at the pre-embedded anchor is insufficient, and The strength of the concrete near the mouth is insufficient, and the concrete at the pre-embedded anchorage has grout leakage and vibration is not dense

These problems are likely to cause the roof concrete to be cracked and pulled up during negative bending moment tension construction; ③ During prefabrication, the concrete leaks into the negative bending moment pre-embedded bellows, and if it is not cleaned in time, the bellows channel is blocked, and the steel strands are difficult to thread And grouting is not smooth, not full

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