Construction Method of Negative Bending Moment Stretching Groove of Prefabricated Beam

A construction method and technology of negative bending moment, applied in manufacturing tools, ceramic molding machines, etc., can solve the problems of concrete slurry leakage, excessive friction coefficient, neglected construction quality, etc., and achieve accurate anchorage pre-embedding and high molding quality. , the effect of rapid construction

Active Publication Date: 2021-05-07
GUANGXI CHANGCHANG ROAD & BRIDGE CONSTR
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  • Claims
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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

Method used

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  • Construction Method of Negative Bending Moment Stretching Groove of Prefabricated Beam

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The construction method of the prefabricated beam negative moment tension groove includes the following steps:

[0022] (1) Negative bending moment tooth plate steel skeleton welding and forming: According to the design requirements, a number of ring bars are integrally pierced and bound on the prefabricated beam reinforcement layer at a distance of 2m, and then welded and fixed to form a prefabricated beam reinforcement skeleton;

[0023] (2) Negative bending moment tension groove formwork installation: put the prefabricated beam steel skeleton into the mold as a roof reinforcement, and then position and insert the formwork around the ring reinforcement according to the design requirements to form a negative bending with a specification of 0.8m×0.8m Rectangular stretching groove; the template described in step (2) is the special template for assembled double-layer comb-shaped stretching groove;

[0024] (3) Installation and positioning of negative moment tooth plate st...

Embodiment 2

[0028] The construction method of the prefabricated beam negative moment tension groove is characterized in that it comprises the following steps:

[0029] (1) Negative bending moment tooth plate steel skeleton welding and forming: According to the design requirements, a number of ring bars are integrally pierced and bound on the prefabricated beam reinforcement layer at a distance of 2.5m, and then welded and fixed to form a prefabricated beam reinforcement skeleton;

[0030] (2) Negative bending moment tension groove formwork installation: put the prefabricated beam steel skeleton into the mold as a roof reinforcement, and then position and insert the formwork around the ring reinforcement according to the design requirements to form a negative bending with a specification of 0.8m×0.8m Rectangular stretching groove; the template described in step (2) is the special template for assembled double-layer comb-shaped stretching groove;

[0031] (3) Installation and positioning of...

Embodiment 3

[0035] The construction method of the prefabricated beam negative moment tension groove is characterized in that it comprises the following steps:

[0036] (1) Negative bending moment tooth plate steel skeleton welding and forming: According to the design requirements, a number of ring bars are integrally pierced and bound on the prefabricated beam reinforcement layer at a distance of 3m, and then welded and fixed to form a prefabricated beam reinforcement skeleton;

[0037] (2) Negative bending moment tension groove formwork installation: put the prefabricated beam steel skeleton into the mold as a roof reinforcement, and then position and insert the formwork around the ring reinforcement according to the design requirements to form a negative bending with a specification of 0.8m×0.8m Rectangular stretching groove; the template described in step (2) is the special template for assembled double-layer comb-shaped stretching groove;

[0038](3) Installation and positioning of ne...

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Abstract

The invention discloses a construction method of a prefabricated beam negative moment stretching groove, which comprises the following steps: (1) negative moment tooth plate reinforcement skeleton welding and forming; (2) negative moment tension groove formwork installation; (3) negative bending (4) Bellows installation; (5) Concrete pouring: After the roof reinforcement is installed, seal the gap reserved in the formwork, and pour concrete from the middle to both ends at one time During the pouring process, pay attention to pouring in the order of the tooth plate first and then the roof, and strengthen the vibration of the steel-intensive parts. After the concrete is cured in the later stage, the negative moment tension groove of the prefabricated beam is obtained. The invention can effectively improve the positioning accuracy of the anchorage and bellows in the negative moment tensioning groove during beam body prefabrication, and can also reduce the probability of roof concrete being cracked during negative moment tensioning construction, and reduce the clogging of the bellows empty channel , so that the steel strands are threaded smoothly and unobstructed, and have broad market promotion 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...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B28B23/04
CPCB28B23/043
Inventor 何克扬覃靖青志刚李胜张伟锋黎修旺况超卢炳秀万春浪钟飞祥张云祺韦世喜黄先滨蒙金钊谢华杰
Owner GUANGXI CHANGCHANG ROAD & BRIDGE CONSTR
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