JP6336310B2 - Hybrid beam - Google Patents

Description

  The present invention relates to a hybrid beam (composite beam) having a reinforced concrete structure at the end and a steel structure at the center.

In recent years, a beam of a composite structure composed of reinforced concrete (RC) and steel (S) structure as a beam frame of a building that makes a part of or all of a large span (hereinafter also referred to as a composite beam or a hybrid beam) Has been adopted. The beam having such a structure is a steel frame in which both ends are covered with RC, and is spanned and joined between columns such as RC structures. Hereinafter, in the hybrid beam, the center portion made of S is referred to as a steel beam portion, and both end portions covered with RC are referred to as a reinforced concrete beam portion (RC beam portion).
In a reinforced concrete beam section of a hybrid beam, generally, a plurality of beam reinforcement bars and a plurality of beam reinforcement bars and a plurality of lateral reinforcement bars surrounding the steel frame are laid out and embedded throughout the reinforced concrete beam section. . This lateral reinforcing bar also includes a concentrated reinforcing bar in which the bar arrangement at the end of the reinforced concrete beam part and the end of the steel beam part are dense.
The hybrid beam is attracting attention as a new construction method that can reduce the weight of the beam because the center part is S-structured, and that the building can be made long span because the beam formation is reduced.

On the other hand, in the hybrid beam, there is no example of providing the through hole for equipment in the reinforced concrete beam part.
The reinforced concrete beam part of the hybrid beam is designed as a general RC structure. When a general RC beam is provided with a through hole, the reinforcement of the through hole is an open reinforcing bar (ring-shaped one) This is done using buckling reinforcements (skewers).

JP2009-24462

However, when the reinforced concrete beam part of the hybrid beam is reinforced with an aperture reinforcement (ring-shaped) or a buckling reinforcement (skewer), reinforcement such as an aperture reinforcement or a buckling reinforcement Muscles become overcrowded.
When these reinforcing bars are overcrowded, the beam main bars and the lateral reinforcing bars are originally densely arranged in the reinforced concrete beam portion, so that it takes time to arrange the bars and the workability deteriorates.
In addition, when the opening of a general RC beam is reinforced from past research examples, shear cracks around the opening after experiencing an earthquake are conspicuous, and the degree of damage to the beam is also remarkable.
The present invention has been made in view of the above points, and can improve the workability of reinforcement of a reinforced concrete beam portion in which a hole for equipment is horizontally formed and reduce the degree of damage in the event of an earthquake. It is an object of the present invention to provide a reinforcing structure of a hybrid beam having an advantageous facility hole.

In order to achieve the above-mentioned object, the present invention covers both ends of a steel frame spanned between opposing columns with reinforced concrete, the central portion of the steel is a steel beam portion, both ends are reinforced concrete beam portions, and the reinforced concrete is provided. The beam portion is a hybrid beam including a plurality of beam main bars arranged in the horizontal direction at the upper and lower portions of the steel frame and a plurality of lateral reinforcing bars surrounding the beam main bars, and is installed in the reinforced concrete beam portion. A hole is formed to penetrate the steel frame horizontally, and a facility hole reinforcing portion is provided to reinforce a portion of the reinforced concrete beam portion around the facility hole. Side bars on both sides parallel to the side faces of the reinforced concrete beam part on the side of the steel frame, the mesh bars being wound around the plurality of beam main bars outside the steel frame An upper surface portion connecting the upper ends of the side surface portions and parallel to the upper surface of the reinforced concrete beam portion above the steel frame, and a lower surface portion connecting the lower ends of the side surface portions and parallel to the lower surface of the reinforced concrete beam portion below the steel frame The side portions on both sides, the upper surface portion, and the lower surface portion are integrated with the reinforced concrete beam portion, and the side portions on both sides are formed with holes that match the holes for equipment, and the side surfaces on both sides. The section has a height extending between the beam main bars located at both ends in the vertical direction of the reinforced concrete beam section, and the upper and lower beam main bars and the portion of the lateral reinforcing bar extending up and down. The upper surface portion and the lower surface portion have a width extending between the beam main bars located at both ends in the width direction of the reinforced concrete beam portion, and the upper and lower beam main bars. , Horizontally above and below the horizontal complement Are arranged to be clamped respectively between the portion of the muscle, the mesh muscle is characterized to bear a portion of the shear force acting on the reinforced concrete beam portion.

According to the present invention, since the mesh reinforcement constitutes a part of the reinforced concrete beam portion, the mesh reinforcement bears a part of the shearing force acting on the reinforced concrete beam portion. Accordingly, the degree of shear cracking and damage of the reinforced concrete beam around the equipment hole is improved.
In addition, because the mesh reinforcement is used, it is possible to reinforce the reinforced concrete beam part of the hybrid beam, which is originally densely reinforced, easily and quickly, and to improve the workability. This is advantageous for shortening the construction period and reducing costs.
Moreover, it is advantageous in absorbing the energy of the earthquake with the mesh streaks and reducing the degree of damage during the earthquake.

It is a front view of the hole reinforcement part for facilities. It is sectional drawing of the hole part for facilities of the hole reinforcement part for facilities. It is the schematic of a hybrid beam. It is a detailed figure in the vicinity of the reinforced concrete beam portion of the hybrid beam.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a general hybrid beam 10 to which the present invention is applied will be described with reference to FIG. 3 and FIG. 4. The hybrid beam 10 is a steel frame such as I steel or H steel spanned between opposing columns 12. It has a structure in which both ends of S are covered with reinforced concrete.
The central part of the steel S is a steel beam part 10A, both end parts are reinforced concrete beam parts 10B, and the steel S has an internal span (length to the column face) and does not penetrate the column 12, FIG. In FIG. 11, reference numeral 11A indicates a stud bolt, and reference numeral 11B indicates a floor slab.

The reinforced concrete beam portion 10B may be made of precast concrete manufactured in advance in a factory, or may be manufactured of on-site concrete. Alternatively, it may be made of half precast concrete, in which case the concrete is post-struck on site. The concrete may be ordinary concrete or fiber reinforced concrete.
The reinforced concrete beam portion 10B is reinforced by a plurality of beam reinforcing bars 14 and a plurality of transverse reinforcing bars 16 surrounding the beam reinforcing bars 14, and fixing of the beam reinforcing bars 14 to the column beam joint is performed by fixing hardware or bending fixing.
Further, in the portion corresponding to the end portion on the column 12 side and the end portion on the steel beam 10A side of the reinforced concrete beam portion 10B, a concentrated reinforcing bar 16A in which the reinforcing bars of the lateral reinforcing bars 16 are arranged densely. In this way, by providing the concentrated reinforcing bars 16A at the end corresponding to the column 12 side and the end on the steel beam 10A side of the reinforced concrete beam portion 10B, stress can be transmitted from the reinforcing bar to the reinforced concrete beam portion 10B. ing.

As shown in FIGS. 1 and 2, the facility hole 20 is provided in the reinforced concrete beam portion 10B near the beam-column joint, and penetrates the reinforced concrete beam portion 10B horizontally.
And the hole reinforcement part 22 for equipment of this invention which reinforces the location of the reinforced concrete beam part 10B in which the hole 20 for equipment was penetrated was provided.

The facility hole reinforcing portion 22 of the embodiment will be described with reference to FIGS. 1 and 2.
The facility hole reinforcing portion 22 is configured by arranging mesh bars 24 at least in the vicinity of both side surfaces of the reinforced concrete beam portion 10B including the periphery of the facility hole 20.
In the present embodiment, the mesh bars 24 are connected to both side surfaces 2402 parallel to both side surfaces of the reinforced concrete beam portion 10B, and upper surface portions 2404 connecting the upper ends of the side surface portions 2402 and parallel to the upper surface of the reinforced concrete beam portion 10B. And a lower surface portion 2406 that connects the lower ends of the side surface portions 2402 and is parallel to the lower surface of the reinforced concrete beam portion 10B.
The side portions 2402 on both sides have a height extending between the beam main bars 14 located at both ends in the vertical direction of the reinforced concrete beam portion 10B.
Moreover, the upper surface part 2404 and the lower surface part 2406 have the width extended between the beam main bars 14 located in the both ends of the width direction of the reinforced concrete beam part 10B.
A hole 2410 that matches the facility hole 20 is formed in the side surface portions 2402 on both sides.
The mesh reinforcement 24 may be any part that constitutes a part of the reinforced concrete beam portion 10B and can bear a part of the shearing force acting on the reinforced concrete beam portion 10B. Various materials can be used.

In the present embodiment, a single mesh bar 24 is wound around the plurality of beam main bars 14, and both side surfaces 2402 of the reinforced concrete beam part 10 </ b> B extend vertically with the upper and lower beam main bars 14. It is sandwiched and disposed between the existing lateral reinforcing bars 16.
In addition, on the upper and lower surfaces of the reinforced concrete beam portion 10B, the upper surface portion 2404 and the lower surface portion 2406 are disposed so as to be sandwiched between the upper and lower beam main bars 14 and the upper and lower horizontal reinforcing bars 16 extending horizontally. Has been.

Thus, if the hole reinforcement part 22 for facilities is comprised, the following effects AC will be exhibited.
Effect A: Since the mesh reinforcement 24 is integrated with the reinforced concrete beam portion 10B and the mesh reinforcement 24 constitutes a part of the reinforced concrete beam portion 10B, the mesh reinforcement 24 bears a part of the shearing force acting on the reinforced concrete beam portion 10B. . Accordingly, the degree of shear cracking and damage of the reinforced concrete beam portion 10B around the equipment hole 20 is improved.
Effect B: Since the mesh reinforcement 24 is used and this mesh reinforcement 24 is arranged using the beam main reinforcement 14 and the lateral reinforcement reinforcement 16, the reinforcing bar arrangement 10B of the hybrid beam 10 in which the reinforcement reinforcement is originally dense is provided. Compared to the case where reinforcement is made using an aperture reinforcing bar, it can be reinforced easily, quickly and reliably, the workability is improved, and it is advantageous for shortening the construction period and reducing costs.
Effect C: The mesh muscle 24 can absorb the energy of the earthquake, which is advantageous in reducing the degree of damage during the earthquake.

Even if the mesh reinforcement 24 is disposed only in the vicinity of both side surfaces of the reinforced concrete beam portion 10B that bears much of the shearing force acting on the reinforced concrete beam portion 10B, the equipment hole reinforcing portion 22 may be configured. Good. In this case, the mesh bars 24 have only the side surface portions 2402 and are attached to the pair of upper and lower beam main bars 14 one by one. However, if the mesh bars 24 are disposed around the entire circumference of the reinforced concrete beam portion 10B as in the embodiment, it is more advantageous in achieving the effects A to C.
Further, the hole 2410 is not formed in the mesh reinforcement 24, and a plurality of mesh reinforcements 24 are arranged on both sides of the reinforced concrete beam portion 10B on the upper, lower, left and right sides of the equipment reinforcing hole 22 to constitute the equipment hole reinforcing portion 22. However, the configuration as in the embodiment is more advantageous in improving the workability, shortening the work period, and reducing the cost.

DESCRIPTION OF SYMBOLS 10 ... Hybrid beam 10A ... Steel beam part 10B ... Reinforced concrete beam part 14 ... Beam main reinforcement 16 ... Lateral reinforcement 20 ... Equipment hole 22 ... Equipment hole reinforcement part 24 ... Mesh reinforcement 2402 ... Side surface portion 2404 …… Upper surface portion 2406 …… Lower surface portion

Claims (2)

Covering both ends of the steel frame spanned between the opposing columns with reinforced concrete, the central part of the steel frame as a steel beam part, both ends as a reinforced concrete beam part, the reinforced concrete beam part above and below the steel frame A hybrid beam having a plurality of beam main bars arranged in a horizontal direction at a location and a plurality of lateral reinforcement bars surrounding the beam main bars ,
A hole for equipment is formed in the reinforced concrete beam portion through the steel frame and penetrating horizontally,
A facility hole reinforcing portion for reinforcing a portion of the reinforced concrete beam portion around the facility hole is provided,
The facility hole reinforcing portion is formed by winding one mesh bar around the plurality of beam main bars outside the steel frame, and is parallel to both side surfaces of the reinforced concrete beam unit at the side of the steel frame. The side portions on both sides, the upper ends of the side portions connected to each other and the upper surface portion parallel to the upper surface of the reinforced concrete beam portion above the steel frame, and the lower ends of the side portions connected to the lower portion of the steel frame are connected to the reinforced concrete beam portion. A lower surface portion parallel to the lower surface,
The side portions on both sides, the upper surface portion, and the lower surface portion are integrated with the reinforced concrete beam portion,
Holes that match the equipment holes are formed on the side surfaces on both sides,
The side portions on both sides have a height extending between the beam main bars located at both ends in the vertical direction of the reinforced concrete beam portion, and the upper and lower beam main bars and the lateral reinforcing bars extending vertically. It is sandwiched and arranged between the parts of
The upper surface portion and the lower surface portion have a width extending between the beam main bars located at both ends in the width direction of the reinforced concrete beam portion, and the upper and lower beam main bars and the upper and lower beam extending horizontally. It is arranged to be sandwiched between the side reinforcement bars,
The mesh reinforcement bears a part of the shearing force acting on the reinforced concrete beam part,
A reinforcing structure for a hybrid beam having a hole for equipment. The mesh streaks are made of metal or carbon fiber,
The reinforcing structure for a hybrid beam having a facility hole according to claim 1.

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