JP2000179081A - Shear reinforcing construction of reinforced concrete building frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent panting shear breakdown generated on the periphery of a pillar in a flat slab, and easily perform shear reinforcement of the shell wall, the foundation slab, or the like of a nuclear reactor building by the use of bar-like shear reinforcement. SOLUTION: For beam part main reinforcements 6a, 7a on the periphery of a pillar in a flat slab, beam type reinforcements 8, 9 formed so as to surround the beam part main reinforcements are provided, the flat slab on the periphery of the pillar is shear reinforced, concrete is confined, and panting shear breakdown is prevented. Otherwise, a plurality of bar-like reinforcements in which facing hardwares are threadedly fitted and fixed to both end parts of threaded bars are standingly arranged in the direction of the slab thickness, or the beam type reinforcement and bar-like reinforcement are jointly used. Further, the bar-like reinforcements are arranged in the shell wall, the foundation slab, or the like of a nuclear reactor building, and by strongly fixing a fixing hardware with the threaded bars by mortar or the like, workability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing a flat slab from being damaged by punching shear or for reinforcing a reinforced concrete body used for shear reinforcement of a foundation slab or a shell wall of a reactor building.

[0002]

2. Description of the Related Art FIG.
(a) shows an example of a large span flat slab in a super high-rise RC building without pillars or beams called a free plan, in which the RC core wall 2 is located at the center of the RC flat slab 1 and is located at the outer periphery. An outer peripheral column 3 of the RC is provided. In the flat slab 1, main bars are arranged vertically and horizontally in a plan view, and the main bars of an outer column row portion and an inner beam portion are densely arranged, so that an outer peripheral beam portion 4 is provided in the outer peripheral portion and the inside of the flat slab 1. And an internal beam 5.

When a seismic force as shown in FIG. 9 (a) acts on such a building, as shown in FIGS. 9 (b) and 9 (c), there is a problem that a punching shear failure A occurs in the flat slab 1. is there. The punching shear fracture A is a local fracture (shear fracture) occurring around the outer peripheral column 3. FIGS. 10 (b) and 10 (c) show the destruction of the slab specimen in an experiment as shown in FIG. 10 (a) under the assumption of an earthquake. This destruction reduces habitability, but at present there is no way to reinforce it.

Conventionally, a rod-shaped shear reinforcement 50 as shown in FIGS. 11 and 12 is used for shear reinforcement of a foundation slab and a shell wall of a reactor building. The shear reinforcement 50 is constituted by fixing a fixing plate 52 to both ends of a screw rebar 51 with fixing nuts 53, and is disposed horizontally on the shell wall 20 (see FIG. 11) and disposed vertically on the base slab 30. (See FIG. 12).

However, in the case of the conventional shear reinforcement 50,
Since the fixing nut 53 is screwed into the screw reinforcing bar 51, play occurs due to vibration during concrete casting, and it is necessary to fix the fixing plate 52 / fixing nut 53 and the screw reinforcing bar 51 by some method. There was a problem that sex was bad.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to prevent punching shear breakage occurring around a column of a flat slab.
It is also an object of the present invention to provide a reinforced concrete frame shear reinforcement structure that can easily perform shear reinforcement of a shell wall or a foundation slab of a reactor building using a bar-shaped shear reinforcement.

[0007]

According to a first aspect of the present invention, there is provided a shear reinforcing structure for a reinforced concrete skeleton, wherein a beam type reinforcing bar having a shape surrounding the beam main reinforcing bar is provided around a beam main bar around a column in a flat slab. (Claim 1: FIG. 1
・ See FIG. 2). In the case of a large span flat slab in a super-high-rise RC building, a beam-type reinforcing bar is provided in the main reinforcement of the outer peripheral beam (column array) and the internal beam of the flat slab. It is preferable to use a beam type reinforcing bar that combines a small hoop bar and a large hoop bar.

The second reinforcing structure for a reinforced concrete frame according to the present invention is characterized in that a bar-shaped reinforcing bar in which a fixing metal is screwed to both ends of a threaded reinforcing bar and fixed with a mortar or the like around a pillar in a flat slab in a slab thickness direction. (See Claim 2: FIGS. 3 and 4).

The third reinforcing structure for a reinforced concrete skeleton according to the present invention is characterized in that a beam-type reinforcing bar surrounding the beam main reinforcing bar is provided at the beam main reinforcing bar around the column in the flat slab, and the beam reinforcing bar around the column in the flat slab is provided. In addition, a plurality of bar-shaped reinforcing bars in which fixing hardware is screwed and fixed to both ends of the screw rebar are provided upright in the thickness direction of the slab (refer to claim 3: FIGS. 5 and 6).

Further, the shear reinforcement by the bar reinforcing bars is not limited to the flat slab, but can be applied to a shell wall or a foundation slab of a reactor building. A plurality of bar-shaped reinforcing bars are provided in parallel with the concrete thickness direction, with fixing hardware screwed to both ends of the screw rebar and fixed with mortar or the like (claim 4: see FIGS. 7 and 8).

[0011] In the above-described configuration, the hoop-shaped beam-type reinforcing bar attached to the beam main reinforcing bar around the column of the flat slab, or at both ends of the screw bar reinforcing bars provided around the column of the flat slab. Punching shear failure around the column of the flat slab during the earthquake due to the shear reinforcement of the flat slab around the column and the concrete restraint by the bar reinforcing bar with anchoring hardware or the combination of the beam type reinforcing bar and the bar reinforcing bar Is prevented.

Further, the shell wall and the foundation slab of the reactor building are sheared and reinforced by bar-shaped reinforcing bars having fixing hardware at both ends of the screw reinforcing bar. Because it is firmly fixed to the screw rebar by vibrating, there is no play due to vibration during concrete casting, and it is possible to eliminate the work of fixing the fixing plate and the fixing nut to the screw rebar as in the past,
Workability is improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. 1 to 6 show an example in which the shear reinforcement structure of the present invention is applied to a large span flat slab of a super high-rise RC building, FIG. 1 shows a first flat slab shear reinforcement structure, and FIG. It is shown.
FIG. 3 shows a second flat slab shear reinforcement structure. FIG. 4 shows the bar reinforcement used in FIG. FIG. 5 shows a third flat slab shear reinforcement structure, and FIG. 6 shows a modification thereof. 7 and 8
The shell reinforcement structure of the present invention is a shell wall of a reactor building,
This is an example applied to a foundation slab.

1 to 6, in a flat slab 1, main bars 6, 7 are arranged vertically and horizontally in a plan view.
The outer peripheral beam portion 4 is formed on the outer peripheral portion of the flat slab 1 by narrowing the arrangement pitch of the main reinforcing bars 6a penetrating the inside horizontally and arranged in the column direction of the outer peripheral columns 3, and is orthogonal to the main reinforcing bars 6a. The internal beams 5 are formed by reducing the arrangement pitch of the main bars 7 a whose ends are arranged in the outer peripheral column 3.

With respect to such a flat slab 1, in the first flat slab shear reinforcement structure, as shown in FIG. 1, the main reinforcing bars 6a and the main reinforcing bars 7a around the outer peripheral columns 3 in the flat slab 1 are each formed with a beam type. Reinforcing bars 8 and 9 are provided to perform shear reinforcement of flat slabs around columns and restrain concrete.

The beam type reinforcing bars 8 and 9 are used as beam main reinforcing bars 6a,
The beam-shaped reinforcing bar 8 is a rectangular closed frame-shaped welded-type hoop bar surrounding the upper and lower bars of the main bar 7a.
The beam-type reinforcing bars 9 are arranged between the main bars 6 and 6 near the column which are more densely arranged than the center of the flat slab so as to be densely arranged. The beam-type reinforcing bars 8 of the beam main reinforcing bars 6a in the external beam portions 4 may be provided only in the vicinity of the outer peripheral columns 3, or may be continuously provided between the adjacent outer peripheral columns 3, 3. It may be.

The beam-type reinforcing bars 8, 9 are small hoop bars 8-1, 9-1 surrounding several beams at the center of the beam main bar 6a, the beam main bar 7a, the beam main bar 6a, and the beam main bar 6a. It is composed of large hoop bars 8-2 and 9-2 surrounding the entire main bar 7a, so that shear reinforcement and the like are firmly performed.

FIG. 2 shows a modified example of FIG.
Two beam-type reinforcing bars 9 are attached between the main bars 6 and 6, and the small hoop bars 9-1 of the beam-type reinforcing bars 9 surround the entire beam portion main bar 7a. The hoop bar 9-2 also surrounds the main bar 7 located outside the beam main bar 7a, so that the shear reinforcement and the like on the internal beam unit 5 side become strong over a wide range.

Next, in the second flat slab shear reinforcement structure shown in FIG. 3, fixing hardware 12 is screwed to both ends of the screw reinforcing bar 11 around the outer peripheral column 3 in the flat slab 1 and fixed with mortar or the like. A plurality of the bar-shaped reinforcing bars 10 are provided upright in the slab thickness direction, and the screw reinforcement 11 and the fixing hardware 12 at both ends shear-reinforce the flat slab around the column and restrain concrete.

As shown in FIG. 4, the fixing hardware 12 has a hexagonal shape in which a disc-shaped fixing plate portion 12a and a female screw 12c are formed integrally on one surface of the fixing plate portion 12a. The nut portion 12b is composed of a columnar nut portion 12b.
The end of the threaded reinforcing bar 11 is screwed into the fixing plate 12a.
Female screw 12c for filling the filler 13 such as high-strength non-shrink mortar from the grout material injection hole 12d and the screw bar 1
1 to fix the screw reinforcement 11 and the fixing hardware 12. The fixing hardware 12 includes a fixing plate portion 12a and a female screw 12c.
Is a metal part integrated with a screw.
Because it is firmly fixed to 1, it does not cause backlash due to vibration during concrete casting.

The length of such a bar-shaped reinforcing bar 10 is such that when it is disposed in the flat slab 1, a suitable concrete cover thickness is secured up and down. In addition, as shown in FIG. 3, it is arranged in a space surrounded by the main muscles 6 and 7 in a rectangular area surrounding the outer peripheral column 3 in plan view. Alternatively, it may be attached to the intersection of the main reinforcement 6 and the main reinforcement 7.

Next, the third flat slab shear reinforcement structure shown in FIGS. 5 and 6 is composed of beam-type reinforcements 8 and 9 and rod-like reinforcements 10.
Are combined. The bar-shaped reinforcing bars 10 are provided in a space surrounded by the main bars 6, the main bars 7, and the beam-shaped reinforcing bars 8 or 9 in a plan view, and a space surrounded by the main bars 6 and the main bars 7.

The above is an example in which the present invention is applied to a large span flat slab of a super high-rise RC building. However, the present invention is not limited to this, and the shear reinforcement structure of the present invention can be applied to other flat slabs.

Next, in the shell wall 20 of the reactor building shown in FIG. 7, main reinforcing bars 21 and 22 are arranged vertically and horizontally at both ends in the thickness direction of the concrete. In the foundation slab 30 shown in FIG. 8, main reinforcements 31 and 32 are arranged vertically and horizontally at upper and lower portions in the concrete thickness direction.

Such a shell wall 20 and a foundation slab 30
In the above, shear reinforcement is performed by using a bar-shaped reinforcing bar 10 in which fixing hardware 12 is screwed to both ends of a threaded reinforcing bar 11 as described above and fixed with a filler such as high-strength non-shrink mortar.

In the shell wall 20 shown in FIG. 7, the bar-shaped reinforcing bars 10 are disposed horizontally at intervals in the vertical direction so as to be located in the space surrounded by the main bars 21 and 22. In the base slab 30 shown in FIG. 8, the bar-shaped reinforcing bars 10 are disposed vertically at an interval on the left and right so as to be located in a space surrounded by the main bars 31 and 32. In any case, the length of the bar-shaped reinforcing bar 10 is set to a length at which a suitable concrete cover thickness can be obtained.

Although an example in which rod-shaped reinforcing bars are provided on a shell wall or a foundation slab of a reactor building has been described, the present invention is not limited to this.
The bar-shaped reinforcing bars of the present invention can be applied to other reinforced concrete frames.

[0028]

Since the present invention has the above-described structure, the following effects can be obtained. (1) Hoop-shaped beam-type reinforcing bars attached to beam main bars around flat slab columns, or bar-shaped reinforcing bars with anchoring hardware at both ends of multiple threaded reinforcing bars provided around flat slab columns Or by the combination of beam-type reinforcement and bar-type reinforcement, shear reinforcement of the flat slab around the column and restraint of concrete,
It is possible to prevent punching shear destruction occurring around the column of the flat slab at the time of an earthquake, and to enhance living performance (at the time of an earthquake). (2) Since the fixing metal of the bar-shaped reinforcing bars is firmly fixed to the threaded reinforcing bar with a filler such as mortar, there is no backlash due to vibration during concrete casting, and the fixing plate and fixing nut as in the past are used. The work of fixing the screw to the rebar can be eliminated, and the workability is improved.

[Brief description of the drawings]

FIG. 1 is an example of a first flat slab shear reinforcement structure of the present invention, (a) is a plan view, (b) is a cross-sectional view in a lateral direction,
(c) is a longitudinal sectional view.

FIGS. 2A and 2B are modifications of FIG. 1, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view in a horizontal direction, and FIG.

FIG. 3 is an example of a second flat slab shear reinforcement structure of the present invention, wherein (a) is a plan view, (b) is a cross-sectional view in a lateral direction,
(c) is a longitudinal sectional view.

FIG. 4 is an example of a rod-like reinforcing bar used in FIG. 3, (a) is an overall side view, (b) is a front view of a fixing plate portion, (c) is a side view of a reinforcing bar end, (d) () Is a cross-sectional view of the nut portion, and (e) is a longitudinal cross-sectional view of the reinforcing bar end.

FIG. 5 is an example of a third flat slab shear reinforcement structure of the present invention, (a) is a plan view, (b) is a cross-sectional view in a lateral direction,
(c) is a longitudinal sectional view.

6 (a) is a plan view, FIG. 6 (b) is a horizontal sectional view, and FIG. 6 (c) is a vertical sectional view.

FIG. 7 is an example in which the shear reinforcement structure of the present invention is applied to a shell wall of a reactor building, where (a) is a sectional view, (b) is a partially enlarged sectional view, and (c) is a side view of a bar reinforcing bar. It is.

8 is an example in which the shear reinforcement structure of the present invention is applied to a foundation slab of a reactor building, (a) is a sectional view, and (b) is a partially enlarged sectional view.

FIG. 9 is a conventional large span flat slab, (a)
1 is an overall plan view, and (b) and (c) are cross-sectional views showing punching shear fracture.

10A is a cross-sectional view showing a method of applying force in a punching shear fracture test, and FIGS. 10B and 10C are plan views showing the state of fracture.
It is a side view.

11 (a) is a cross-sectional view and FIG. 11 (b) is a partially enlarged cross-sectional view showing a conventional shear reinforcement structure on a shell wall of a reactor building.

12 (a) is a cross-sectional view and FIG. 12 (b) is a partially enlarged cross-sectional view showing a conventional shear reinforcement structure in a foundation slab of a reactor building.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flat slab 2 ... Core wall 3 ... Peripheral pillar 4 ... Peripheral beam 5 ... Internal beam 6 ... Main bar 6a ... Beam main bar 7 ... Main bar 7a ... Beam main bar 8 ... Beam type Reinforcing bar 9 Beam reinforcing bar 10 Bar reinforcing bar 11 Screw rebar 12 Fixing hardware 12a Fixing plate 12b Nut 12c Female screw 12d Grout material injection hole 13 Filler 20 ... Shell wall 21 ... Main bar 22 ... Main bar 30 ... Foundation slab 31 ... Main bar 32 ... Main bar

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Norio Suzuki, Inventor 2-19-1, Tobita-Shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. (72) Inventor Makoto Maruta 2-9-1, Tobita-Shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (72) Inventor Takayuki Inoue 2-9-1-1, Tobita-Shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute F-term (reference) 2E164 AA02 AA13 BA02 BA27 CA12

Claims (4)

[Claims] 1. A shear reinforcing structure for a reinforced concrete skeleton, wherein a beam type reinforcing bar surrounding the beam main reinforcing bar is provided around a beam main bar around a column in a flat slab. 2. A reinforced concrete skeleton comprising a plurality of bar-shaped reinforcing bars, which are fixed by screwing fixing hardware to both ends of a threaded reinforcing bar in the slab thickness direction, around columns in a flat slab. Shear reinforcement structure. 3. A beam-type reinforcing bar having a shape surrounding the beam main reinforcement around the column in the flat slab, and fixing hardware is provided around the column in the flat slab and at both ends of the screw bar. A shear reinforcing structure for a reinforced concrete skeleton, wherein a plurality of bar-shaped reinforcing bars fixed by screwing are arranged in the slab thickness direction. 4. A reinforced concrete skeleton, wherein a plurality of bar-shaped reinforcing bars fixed by screwing fixing hardware to both ends of a threaded reinforcing bar are arranged in a reinforced concrete skeleton of the structure in parallel with the concrete thickness direction. Shear reinforcement structure.