JP6486534B2 - 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 beam weight and reduce the length of the beam because the center part is made of S, and that can provide a long span of the beam.

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 formed to penetrate horizontally, and can also absorb the energy of earthquakes and durability of a hybrid beam. It is an object of the present invention to provide a reinforcing structure for a hybrid beam having a hole for equipment which is advantageous in increasing the height of the beam.

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. beam portion includes a plurality of beams main reinforcement that each of the portions of the upper and lower of the steel provided Te smell, a hybrid beam and a plurality of transverse reinforcement surrounding them beam main reinforcement, Contact to the reinforced concrete beam portion There, the formed equipment hole penetrates the steel horizontal, the plant hole reinforcing portion for reinforcing the portion of the reinforced concrete beams of the peripheral equipment for the hole is provided, the plant hole reinforcement portion, the hole that matches the equipment holes are formed, and a reinforcing plate covering the sides of portions of the reinforced concrete beam portion including a periphery of the equipment hole, said reinforced concrete with said reinforcing plate It is composed of a tendon tightened on both sides of parts, the tendon, and between the steel and said plurality of beams main reinforcement that is provided above the steel, said plurality of beams provided below the steel It is provided between the main bar and the steel frame .

According to the present invention, since the reinforcing plate constitutes a part of the surface of the reinforced concrete beam portion, the reinforcing plate 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 reinforcing plate is used, it is easier and faster to reinforce the reinforced concrete beam part of the hybrid beam, where the reinforcing bar is originally overcrowded, using a hole reinforcing bar, improving workability. This is advantageous for shortening the construction period and reducing costs.
In addition, the reinforcing plate can absorb the energy of the earthquake, which is advantageous for enhancing the durability of the hybrid beam.
Further, it is possible to reduce or omit the lateral reinforcing bars in the portion reinforced by the reinforcing plate.

It is a front view of the hole reinforcement part for facilities of a 1st embodiment. It is sectional drawing of the hole part for facilities of 1st Embodiment. It is a front view of the modification of the hole reinforcement part for facilities of 1st Embodiment. It is a front view of the hole reinforcement part for facilities of 2nd Embodiment. It is sectional drawing of the hole part for facilities of 2nd Embodiment. It is a front view of the hole reinforced part for facilities of a 3rd embodiment. It is sectional drawing of the hole part for equipment of 3rd Embodiment. 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. 8 and FIG. 9. 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 22A of the first embodiment will be described with reference to FIGS.
In the first embodiment, a pair of side surface parts 2402 covering at least both side surfaces of the reinforced concrete beam part 10B including the equipment hole 20 and the lower surfaces of the reinforced concrete beam part 10B by connecting the lower ends of the side surface parts 2402 to each other. A reinforcing plate 24 having a lower surface portion 2404 covering the surface is provided.
The reinforcing plate 24 is made of steel, and is covered with the reinforcing plate 24 on both side surfaces and the lower surface of the reinforced concrete beam portion 10B including the periphery of the equipment hole 20, and the reinforcing plate 24 by the tension material 26 from both horizontal sides of the reinforced concrete beam portion 10B. These two side surface portions 2402 are fastened to both side surfaces of the reinforced concrete beam portion 10B, thereby constituting the equipment hole reinforcing portion 22A.
In the present embodiment, the side surface portions 2402 on both sides are formed to have a size covering both side surfaces of the reinforced concrete beam portion 10B including the facility holes 20, and the side surface portions 2402 on both sides match the facility holes 20. The hole 2410 to be formed is formed, for example, so that the equipment pipe can be penetrated into the reinforced concrete beam portion 10B through the equipment hole 20 and the hole 2410.
Conventionally known various structures such as bolts, PC steel bars, and low yield point steel can be used as the tension member 26. Both sides 2402 are fastened to both sides of the reinforced concrete beam 10B by the tension member 26, and reinforcing plates are used. 24 is integrated with the reinforced concrete beam portion 10B.
In this case, the use of a low yield point steel as the tendon 26 is advantageous in that it can be replaced after deformation.
In addition, in the part of the hole 20 for facilities, although the part extended to the upper and lower sides of the horizontal reinforcement 16 is cut | disconnected by the hole 20 for installation, and it isolate | separates into upper and lower, the reinforcement board 24 is in the location from which this horizontal reinforcement 16 was isolate | separated. The side surface portion 2402 is positioned to reinforce this portion. When the hybrid beam 10 is constructed from the beginning, a U-shaped reinforcing bar may be placed on the beam main reinforcing bar from above and below in the portion of the equipment hole 20.

Thus, if the hole reinforcement part 22A for facilities is comprised, the following effects AD will be exhibited.
Effect A: Since the reinforcing plate 24 is integrated with the reinforced concrete beam portion 10B, and the reinforcing plate 24 constitutes a part of the surface of the reinforced concrete beam portion 10B, the reinforcing plate 24 has a part of the shearing force acting on the reinforced concrete beam portion 10B. bear. 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 reinforcing plate 24 is used, the reinforced concrete beam portion 10B of the hybrid beam 10 in which the reinforcing bars are originally densely packed can be easily and quickly reinforced as compared with the case where the reinforcing reinforcing bar 24 is used to reinforce the reinforcing beams. Workability is improved, which is advantageous for shortening the construction period and reducing costs.
Effect C: The reinforcing plate 24 can absorb earthquake energy, which is advantageous in increasing the durability of the hybrid beam 10.
In addition, when the tension member 26 is configured to be detachable, the reinforcing plate 24 can be replaced when the reinforcing plate 24 is damaged by an earthquake, which is advantageous for easy maintenance.
In this case, the size of the reinforcing plate 24 may be partial or full, and as shown in FIG. 3, the reinforcing plate that covers the entire area of both side surfaces and the entire lower surface of the reinforced concrete beam portion 10B. If 24 is used, it will become more advantageous in absorbing the energy of an earthquake and improving the durability of the hybrid beam 10.
Effect D: Since the reinforcing plate 24 bears a part of the shearing force acting on the reinforced concrete beam portion 10B, it is possible to reduce or omit the lateral reinforcing bars 16 of the portion reinforced by the reinforcing plate 24.

Next, the facility hole reinforcing portion 22B of the second embodiment will be described with reference to FIGS. In the following description of the embodiment, the same portions and members as those in the first embodiment are denoted by the same reference numerals, the description thereof is omitted, and different points are mainly described.
The second embodiment is different from the first embodiment in that two steel reinforcing plates 30 having a smaller width than that of the first embodiment are used.
That is, in the second embodiment, at the locations of the reinforced concrete beam portions 10B on both sides of the facility hole 20 in the longitudinal direction of the hybrid beam 10, at least both side surfaces and the lower surface are the both side surface portions 3002 and the lower surface portion 3004 of the reinforcing plate 30, respectively. In addition, both side surface portions 3002 of each reinforcing plate 24 are tightened by the tension members 26 from both sides in the horizontal direction of the reinforced concrete beam portion 10B, thereby configuring the facility hole reinforcing portion 22B.
The configuration of the tendon 26 is the same as that of the first embodiment.
According to the second embodiment, the locations of the reinforced concrete beam portions 10B on both sides of the facility hole 20 in the longitudinal direction of the hybrid beam 10 can be reinforced by the two reinforcing plates 30, so that the same as in the second embodiment. , Effects AD are produced.

Next, the facility hole reinforcing portion 22C of the third embodiment will be described with reference to FIGS.
The third embodiment is different from the first embodiment in that a carbon fiber sheet is used as the reinforcing plate 32.
That is, the side surface portions 3202 on both sides of the reinforcing plate 32 made of a carbon fiber sheet are formed to have a size covering both side surfaces of the reinforced concrete beam portion 10B including the facility holes 20. A hole 3210 matching the service hole 20 is formed.
Then, both side surfaces 3202 of both sides of the reinforced concrete beam portion 10B are covered and the lower surface is covered by the lower surface portion 3204, and both side surface portions 3202 of the reinforcing plate 32 are tightened by the tension members 26 from both sides in the horizontal direction of the reinforced concrete beam portion 10B. Thereby, the hole reinforcing part 22C for facilities is comprised.
The configuration of the tendon 26 is the same as that of the first embodiment.
According to the third embodiment, the effects A to D are produced as in the first embodiment, and the reinforced concrete beam portion 10B can be reinforced with the reinforcing plate 32 made of a lightweight carbon fiber sheet. The hole reinforcing portion 22C can be reduced in weight, which is advantageous in terms of good workability.

In the above-described embodiment, the case where the reinforcing plates 24, 30, and 32 have the side surface portions 2402, 3002, and 3202 on both sides and the lower surface portions 2404, 3004, and 3204 has been described. 2404, 3004, and 3204 can be omitted. However, when the reinforcing plates 24, 30, and 32 having the lower surface portions 2404, 3004, and 3204 are used as in the embodiment, the lower surface portion is compared with the reinforcing plates 24, 30, and 32 that do not have the lower surface portions 2404, 3004, and 3204. 2404, 3004, 3204 also bears a part of the shearing force acting on the reinforced concrete beam portion 10B, so that it is more advantageous in achieving the effects A to C, and because it becomes one component, the reinforcing plates 24, 30, 32 This is also advantageous for easy handling.
Moreover, it is arbitrary, such as adding the upper surface part which covers the upper surface of the reinforced concrete beam part 10B.
The facility hole reinforcing portions 22A to 22C of the present invention can be applied both when the hybrid beam 10 is constructed from the beginning or when the existing hybrid beam 10 is pierced with the facility hole 20 to be reinforced. It is.

DESCRIPTION OF SYMBOLS 10 ... Hybrid beam 10A ... Steel beam part 10B ... Reinforced concrete beam part 14 ... Beam reinforcement 16 ... Lateral reinforcement 20 ... Equipment hole 22A-22C ... Equipment hole reinforcement part 24, 30, 32 ... ... Reinforcing plate 2402, 3002, 3202 ... Side face part 2404, 3004, 3204 ... Bottom face part 26 ... Tension material

Claims (7)

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 plurality of beam main reinforcement provided Te smell each occurrence, a hybrid beam and a plurality of transverse reinforcement surrounding them beam main reinforcement,
Oite the reinforced concrete beam portion facilities, holes are formed through the steel horizontal,
A facility hole reinforcing portion for reinforcing a portion of the reinforced concrete beam portion around the facility hole is provided,
The plant hole reinforcing section, said holes matching the equipment holes are formed, and a reinforcing plate covering the sides of portions of the reinforced concrete beam portion including a periphery of the equipment hole, said reinforced concrete with said reinforcing plate It is composed of tension materials that are tightened on both sides of the beam,
The tendon is provided between the plurality of beam main bars and the steel frame provided above the steel frame, and between the plurality of beam main bars and the steel frame provided below the steel frame. Reinforcing structure of hybrid beam having equipment holes. The reinforcing plate is composed of a pair of reinforcing plates, and both the side surfaces of the pair of reinforcing plates and the reinforced concrete beam portion are tightened by the tension material.
  The reinforcement structure of the hybrid beam which has the hole for facilities of Claim 1 characterized by the above-mentioned.   The reinforcing plate has side surfaces on both sides that cover both side surfaces of the reinforced concrete beam portion, and a lower surface portion that connects the lower ends of the side surfaces on both sides and covers the lower surface of the reinforced concrete beam portion.
  The reinforcement structure of the hybrid beam which has the hole for facilities of Claim 1 characterized by the above-mentioned.   The reinforcing plate is composed of a first reinforcing plate and a second reinforcing plate,
  Each of the first reinforcing plate and the second reinforcing plate is an upper edge of each of the reinforced concrete beam portions at both side surfaces of the reinforced concrete beam portion located on both sides of the facility hole in the longitudinal direction of the reinforced concrete beam portion. A pair of side surfaces covering from the bottom edge to the bottom edge
  The reinforcement structure of the hybrid beam which has the hole for facilities of Claim 1 characterized by the above-mentioned.   The plurality of beam main bars are arranged in a horizontal direction with respect to the steel frame.
  The reinforcement structure of the hybrid beam which has the hole for facilities of any one of Claims 1-4 characterized by the above-mentioned. The tendon is detachable with respect to the reinforced concrete beam portion and the reinforcing plate,
The tendon is made of low yield point steel,
The reinforcing structure of a hybrid beam having a facility hole according to any one of claims 1 to 5 . The reinforcing plate is composed of a steel plate or a carbon fiber sheet,
The reinforcing structure of a hybrid beam having a hole for equipment according to any one of claims 1 to 6 .

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