JP7229836B2 - Hollow slab structure - Google Patents

Description

The present invention relates to precast concrete plates and hollow slab structures used for hollow concrete slabs.

As a construction method for concrete slabs that are used as flooring and ceiling materials for buildings, a lightweight embedded material (void formwork) is embedded in the concrete for the purpose of reducing weight and improving sound insulation. It is known.
Usually, a precast concrete plate is installed between the beams, and the upper end reinforcement is laid on top of the precast concrete plate, which is made by placing the embedding material on the substantially rectangular precast concrete substrate in which the slab bottom reinforcement and truss reinforcement are embedded in advance at a factory or the like. A floor slab is formed by placing cast-in-place concrete (see Patent Document 1).
For example, in a high-rise building, a building having beams arranged in a parallel cross shape in a plan view is constructed by installing rectangular precast concrete plates between the beams, as shown in FIG.
In addition, in the case of a double-tube structure building, as shown in FIG. 7, fan-shaped precast concrete plates are constructed between columns and beams in the corner regions of the building (see Patent Document 2). As a result, floor slabs can be constructed at the corners of the building that do not have beams that connect the inner frame and the outer frame. However, the part where the width of the sector becomes narrow (the inner side of the building) becomes a collection of sharp-angled boards, which makes it difficult to fit, and causes inconveniences such as the inability to install a floor opening in that range. However, there was a problem that the construction was difficult and costly.
On the other hand, when constructing a slab by placing rectangular precast concrete plates adjacent to each other, as shown in FIG. However, since the embedding material is installed on the board, it becomes an obstacle, and the sufficient length of the connecting bar cannot be obtained, making it difficult to ensure the continuity of the adjacent precast concrete plates. be. In consideration of this problem, Patent Literature 3 discloses a technique of thinning out and installing the embedding material.

JP-A-07-292828 JP 2004-270153 A JP 2006-138166 A

The present invention has been made to solve the above-described problems, and it is possible to ensure the continuity of adjacent precast concrete plates without impairing the purpose of reducing the weight of concrete slabs, and to improve workability. An object of the present invention is to provide a precast concrete plate excellent in

(1) In a building with a double-tube structure that has an inner frame and an outer frame and has no beams that connect the inner frame and the outer frame, the corners of the inner frame and the corners of the outer frame A floor slab structure in a substantially rectangular corner region between
A precast concrete plate comprising a concrete substrate having a truss bar embedded at its lower end and an embedding material provided on the concrete substrate , wherein when the precast concrete plates are used adjacent to each other, A precast concrete plate having a rectangular shape in a plan view and having a space between the lower surface of the embedding material and the concrete substrate for passing connecting bars laid across the adjacent precast concrete plates , and having a length thereof A plurality of said precast concrete plates arranged continuously in one direction so that their side portions are adjacent to each other, said adjacent precast concrete plates, and said precast concrete plates erected between the beams of said inner peripheral frame and said outer peripheral frame. However, the long side portions of the adjacent precast concrete plates, the long side portions of the precast concrete plates installed between the beams of the inner peripheral frame and the outer peripheral frame, and the short sides of the adjacent precast concrete plates and the long side portion of the precast concrete plate installed between the beams of the inner peripheral frame and the outer peripheral frame,
The connecting bars straddle the adjacent precast concrete plates and straddle the precast concrete plates erected between the adjacent precast concrete plates and the beams of the inner peripheral frame and the outer peripheral frame. It is laid through the space and concrete is placed on it,
A hollow slab structure in the corner area of a double-tube structure building.
(2) The embedding material has a side surface along the side of the precast concrete plate that slopes inward from the precast concrete plate from top to bottom. 2 is a hollow slab structure in a corner region of a double-tube structure building according to 1. FIG .

(1) When precast concrete plates are used adjacent to each other, a space for passing connecting bars laid across the adjacent precast concrete plates is provided between the lower surface of the embedding material and the concrete substrate. Therefore, the continuity of adjacent precast concrete plates can be secured because it is possible to insert and lay connecting bars of a necessary and sufficient length through the space without impairing the purpose of reducing the weight of the concrete slab. can be done. Workability at the site is not complicated, and construction can be performed by almost the same method as before.
Also, when constructing a floor slab at the corner of a double-tube structure building without beams that connect the inner and outer frames, it avoids complication of fitting and creates inconveniences such as the inability to provide floor openings. never.
(2) The lower surface of the embedding material is provided with a plurality of legs which are grounded and fixed to the concrete substrate, and the space is provided easily and reliably by the structure having the space between the plurality of legs. can be done.
(3) A hollow slab structure in which the precast concrete plates are arranged in a row, connecting bars are laid through the space over the adjacent precast concrete plates, and concrete is poured on the hollow slab structure. It is possible to reduce the weight and improve workability.

A precast concrete plate 1 is shown, (a) is a plan view, and (b) is a cross-sectional view taken along line bb of (a). 1 is a perspective view of an embedding material 10; FIG. FIG. 2 is a plan view showing an arrangement example of precast concrete plates 1 applied to a building 30; FIG. 4 is a sectional view taken along the line aa of FIG. 3; FIG. 3 is a cross-sectional view showing a joint of precast concrete plates; FIG. 2 is a plan view showing a conventional arrangement example of precast concrete plates applied to a building 30; FIG. 2 is a plan view showing a conventional arrangement example of precast concrete plates applied to a building 30;

In a precast concrete plate comprising a precast concrete substrate with truss bars embedded at the bottom end and an embedding material provided on the substrate, precast concrete is placed between the bottom surface of the embedding material and the precast concrete substrate When the plates are used adjacent to each other, the precast concrete plate is configured to have a space for passing connecting bars laid across the adjacent precast concrete plates.

A precast concrete plate 1 has a rectangular shape in plan view, and includes a concrete substrate 2, bottom reinforcements 3 and 4 embedded therein in a grid pattern, truss reinforcements 5 embedded at the bottom end, and an embedding material 10. ing. This precast concrete plate 1 is manufactured at a factory or construction site.

The truss bar 5 includes a bifurcated lattice bar 51, an upper chord member 52 fixed to each top of the lattice bar 51, and two lower chord members 53, 53 fixed to the lower end of each lattice bar 51. there is The lower ends of the lower chord members 53 and 53 and the lattice reinforcement 51 are embedded inside the concrete substrate 2 on the lower reinforcements 3 and 4 . The truss bars 5 are arranged so as to extend in the longitudinal direction of the concrete substrate 2 .

An embedding material 10 is arranged between the truss bars 5 . The embedding material 10 is a three-dimensional foamed product made of synthetic resin. Usually formed solid. As shown in FIG. 2, the embedding material 10 has a plurality of legs 11, 11 on its lower surface that are grounded and fixed to the concrete substrate 2, and a space between the legs 11, 11. 12. The legs 11 are fixed to the concrete substrate 2 by bonding to the concrete substrate 2, partially embedding them, or by fixing means such as nailing. An upper portion of the embedding material 10 is provided with a protrusion 13 protruding upward from the upper surface. By adding the convex portion 13 as a void portion in a state where the upper end reinforcement is arranged, the weight of the slab to be constructed can be reduced by the amount added as the void portion.

As described above, there is a space 12 between the lower surface of the embedding material 10 and the concrete substrate 2, and when the precast concrete plates 1 are used adjacent to each other, the space 12 is formed on the adjacent precast concrete plates 1. It becomes the space part 12 for passing the connection muscle laid astride. The height of this space 12 is usually about 40 to 60 mm.
The shape of the embedding material 10 is not limited to the one described above, and various three-dimensional shapes can be adopted. The size and number of the embedding materials 10 are set according to need. The embedding material 10 having the structure described above is preferably arranged along at least four sides of the concrete substrate 2 .

The precast concrete plate 1 constructed as described above is suitably used for constructing slabs at the corners of a building 30 having a double tube structure as shown in FIG. 3, for example.
In the corner region of the building 30, the portion indicated by dotted hatching is the portion to which the precast concrete plate 1 is applied. In this region, a plurality of precast concrete plates 1 are arranged in series in one direction so that their long side portions are adjacent to each other and are connected to each other. These precast concrete plates 1 and precast concrete plates 1a and 1b installed between the beams of the inner frame 31 and the outer frame 32 are adjacent to each other and connected.

In construction, the joints between the adjacent precast concrete plates 1 (and 1a, 1b) (the joints between the long side portions of the precast concrete plates 1, 1a and the short side portions of the precast concrete 1 and the long side portions of the precast concrete 1b) joints), lay connecting bars across the adjacent precast concrete plates.
At this time, the precast concrete plate 1 (and 1a, 1b) is provided with the embedding material 10. As shown in FIG. Since the space part 12 for passing the connection bar 8 is provided, it is possible to secure the reinforcing bar length required to secure the continuity of the connected precast concrete plates 1, 1a, 1b.
In the construction, the connecting bars 8 are laid in the same manner as in the ordinary construction method, and after the bar arrangement is completed, the upper end bars are arranged in a grid pattern. After finishing the necessary bar arrangement work, cast-in-place concrete is placed on the precast concrete plate 1 to a predetermined thickness, completing the work and constructing the hollow slab. The finished slab functions as a bi-directional slab.

Note that FIG. 5 shows an example in which the cross-sectional shape of the embedding material 10 is formed in a trapezoidal shape with a large top side and a small bottom side. The embedding material 10 is positioned along the sides of the precast concrete plate 1 (in the illustrated example, the long side of the precast concrete plate 1), and the side faces of the precast concrete plate 1 extend from the top to the bottom (lower surface). It has an inwardly slanted surface 15 . Having such an inclined surface 15 facilitates the work of inserting the connecting muscle 8 into the space 12 .
Reference numeral 16 denotes a pouring hole for pouring cast-in-place concrete, which is provided so as to penetrate from the upper surface to the lower surface of the embedding material 10 .

Although the embodiments have been described above with reference to examples, the present invention is not limited to the above-described examples, and additions, modifications, etc. can be made as appropriate within the scope of the present invention.
The embedding material has legs on its bottom surface, but instead of providing legs, the embedding material is fixed to the truss bar by providing a connecting part to the truss bar on the upper part of the embedding material. Alternatively, a jig may be used to fix the embedded material to the truss bar.

1 Precast Concrete Board 1a Precast Concrete Board 1b Precast Concrete Board 2 Concrete Substrate 3 Bottom Reinforcement 4 Bottom Reinforcement 5 Truss Reinforcement 8 Connecting Reinforcement 10 Embedding Material 11 Leg Part 12 Spatial Part 30 Building

Claims (2)

Approximately between the corners of the inner and outer frames of a double-tube structure building that has an inner and outer frame and has no beams that connect the inner and outer frames. A floor slab structure in rectangular corner regions,
A precast concrete plate comprising a concrete substrate having a truss bar embedded at its lower end and an embedding material provided on the concrete substrate , wherein when the precast concrete plates are used adjacent to each other, A precast concrete plate having a rectangular shape in a plan view and having a space between the lower surface of the embedding material and the concrete substrate for passing connecting bars laid across the adjacent precast concrete plates , and having a length thereof A plurality of said precast concrete plates arranged continuously in one direction so that their side portions are adjacent to each other, said adjacent precast concrete plates, and said precast concrete plates erected between the beams of said inner peripheral frame and said outer peripheral frame. However, the long side portions of the adjacent precast concrete plates, the long side portions of the precast concrete plates installed between the beams of the inner peripheral frame and the outer peripheral frame, and the short sides of the adjacent precast concrete plates and the long side portion of the precast concrete plate installed between the beams of the inner peripheral frame and the outer peripheral frame,
The connecting bars straddle the adjacent precast concrete plates and straddle the precast concrete plates erected between the adjacent precast concrete plates and the beams of the inner peripheral frame and the outer peripheral frame. It is laid through the space and concrete is placed on it,
Hollow slab construction in the corner area of a double-tube construction building. 2. The embedding material according to claim 1, wherein a side surface of said embedding material located along a side of said precast concrete plate has an inclined surface that slopes inward of said precast concrete plate from top to bottom. hollow slab construction in the corner area of a double-tube structure building.

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