JPH07292828A - Precast synthesized voiod slab and structure thereof - Google Patents

Abstract

PURPOSE:To prevent cracks and vibratory troubles and reduce the weight and increase the sound insulation effect, by laying precasrt concrete base boards between beams at the construction site and arranging reinforcements in the joints on the base boards and further, place cast-in-place concrete on the base boards. CONSTITUTION:The bottom reinforcements 10 of a slab, the lower end of truss rods 20, the lower end of shearing reinforcements 33 of the reinforcements 30 of the inside concrete and the lower end reinforcements 32 are buried and a specified number of base board 1 in which void forms 2 are fixed are laid down between beams. The lower end reinforcements 24 are placed on the joint 5 so as to stride the joint 5 from a base board 1 to another base board 1. After completion of arrangement of the lower end reinforcements 24, the upper end reinforcements 31 of the reinforcements 30 of the inside concrete are arranged in the right- angled crossing direction above the upper chord 21 of the truss rods. In this time, the upper end reinforcements 42 of slab are arranged in parallel with the upper end reinforcements 31 at the same time with the arrangement work or almost the same time. Thereafter, moreover, the upper end reinforcements 41 of slab are arranged in the right-angled direction above the upper end reinforcements 42 of slab or the upper end reinforcements 31. After finish of all arrangement of reinforcements, cast-in-place concrete 8 is placed on the base board 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast synthetic slab, and more particularly to a void slab composed of a precast concrete substrate having reinforcing bars arranged in two intersecting directions and cast-in-place concrete.

[0002]

^2. Description of the Related Art When constructing a large floor plan having a floor area of about 40 to 100 m ^{2, a} reinforcing bar is arranged on a form board,
When a concrete floor slab made by placing concrete is used, problems such as cracking and vibration damage under long-term loading occur. A waffle slab is known as a structure that solves these problems. Further, in addition to the same purpose, in order to reduce the weight and improve the sound insulation effect, a hollow concrete slab in which a lightweight embedding material is arranged on a precast concrete substrate and embedded in the concrete is disclosed in Japanese Patent Laid-Open No. 208411 and Japanese Patent Laid-Open No. 5-2
08410.

As shown in FIG. 4, the hollow concrete slab has a precast concrete substrate 50 in which lattice-shaped slab lower end streaks 54 are entirely embedded, and a lower end portion is embedded in the concrete substrate 50 so as to be arranged in one direction. A plurality of truss reinforcements 53, an embedding material 51 fixed between the truss reinforcements 53 on the precast concrete substrate 50 by a fastener or an adhesive, and a grid arranged on the entire surface of the truss reinforcements 53. -Shaped slab upper end streak 52 and cast-in-place concrete cast on the precast concrete substrate 50 until the slab upper end streak 52 and the embedding material 51 are buried.

[0004]

As described above, the conventional hollow concrete slab is a unidirectional slab. Therefore, in a rectangular slab having a large side length ratio, the hollow concrete slab should be installed between the beams in the short side direction. For example, the truss muscles 53 embedded inside act effectively in terms of structural strength. However, in a slab having a small side length ratio, that is, a slab close to a square, there is a problem in that stress resistance cannot be expected in the direction of the truss bars 53 embedded in the hollow concrete slab.

In the waffle slab, the beams are orthogonal to each other.
Although it exerts the same structural effect as the floor arranged in a grid pattern in the direction, the bottom surface of the slab is not flat and uneven, so in a house that requires many partition walls, The storage with the upper end of the partition wall becomes complicated, and if the storage is improper, the sound insulation may be defective. Furthermore, because of the shape of the waffle slab, it is difficult to make it a composite slab that uses a precast concrete substrate as a formwork, and the conventional method of forming it using cast-in-place concrete using formwork plates and supports has to be adopted. Therefore, there is a problem that it is difficult to save labor in construction.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to construct a large floor plan by applying stress even to a rectangular slab having a large side length ratio and a substantially square slab having a small side length ratio. Resistance is expected, therefore, problems such as cracks and vibration disturbance do not occur even under long-term load, the bottom surface of the slab and the top of the partition wall can be easily housed, and the weight reduction and sound insulation effect are also improved. It is to provide a precast synthetic void slab structure that can be used, and a precast synthetic void slab formed by the structure.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above objects, and its gist is to provide a precast concrete substrate and a lower end embedded in the precast concrete substrate in two directions intersecting with each other. Arranged rebar assembly, an embedding material fixed in a position surrounded by the rebar assembly on the precast concrete substrate,
A precast synthetic void slab structure comprising the reinforcing bar assembly and the concrete cast on the precast concrete substrate until the embedding material is embedded.

In the precast synthetic void slab structure of the present invention, the precast concrete substrate is a substantially rectangular concrete substrate in which slab lower end reinforcements and truss reinforcements are buried in advance in a factory or a construction site. A floor slab is formed by erection and pouring cast-in-place concrete on it. here,
This precast concrete substrate acts as a form at the time of cast-in-place concrete, and after hardening of the cast-in-place concrete, it forms a floor slab together, so it is possible to omit the installation and removal of the form, It is possible to shorten the construction period. Furthermore, since the lower surface of the precast concrete substrate can be made flat,
The slab bottom surface and the partition wall top edge can be simplified to be installed, improving workability.

In the precast synthetic void slab structure of the present invention, the rebar assembly means a plurality of lattice muscles arranged in a bifurcated shape, an upper chord muscle arranged in the axial direction of the top of the lattice muscles, and lower ends of the lattice muscles. A truss reinforcement consisting of two lower chord members arranged in the, or a plurality of rectangular shear reinforcements and two upper end reinforcements arranged in each of the upper and lower two corner axis directions of the shear reinforcement. Or a bottom reinforcing bar assembly, or a plurality of “U” -shaped shear reinforcing bars and one upper reinforcing bar and one upper reinforcing bar arranged in the axial direction of the upper and lower corners of the shear reinforcing bars, respectively. It can be a rebar assembly including a lower end bar. By embedding the lower end of such a rebar assembly in a precast concrete substrate, the rebar assembly can be expected to act as a connector to cast-in-place concrete.

In the precast synthetic void slab structure of the present invention, one of the rebar assemblies is selected, and the lower chord member and the lower end bar of the rebar assembly and the lower end of the shear reinforcing bar are embedded in the precast concrete substrate. However, they are arranged in the intersecting direction. Here, the crossing direction, one can be the same as the longitudinal direction of the precast concrete substrate, the other can be a direction orthogonal to the longitudinal direction,
Further, the reinforcing bar assemblies used in the intersecting directions may be the same reinforcing bar assembly or different kinds of reinforcing bar assemblies. By thus arranging the reinforcing bar assembly in the longitudinal direction of the precast concrete substrate, when this longitudinal direction is set as the erection direction between the beams, the precast concrete substrate can support the casting load of cast-in-place concrete. In addition to being able to do so, the effect of sharing a long-term load can be expected. Further, the reinforcing bar assembly embedded in the direction orthogonal to the longitudinal direction can also be expected to have an effect of sharing a long-term load.

In the precast synthetic void slab structure of the present invention, the embedding material fixed at a position surrounded by the rebar assembly on the precast concrete substrate is
A foamed molded product of a synthetic resin, for example, a solid cuboid or rectangular parallelepiped formed by one having closed cells such as polystyrenic foam, or a space formed on the bottom surface side of the cubic and rectangular parallelepiped. It can be box-shaped. By using such an embedding material, it is possible to reduce the weight of the floor slab and also improve the sound insulation effect.

[0012] Another aspect of the present invention is to provide a plurality of the precast composite void slabs installed in parallel between the beams and a plurality of reinforcing bars arranged at joints on the adjacent precast concrete substrates. The pre-cast synthetic void slab is equipped with.

In the precast synthetic void slab of the present invention, the plurality of reinforcing bars arranged at the joints on the adjacent precast concrete substrates are placed so as to intersect the joints extending in the longitudinal direction of the precast concrete substrate. The fixed and fixed rebar is preferably provided over the entire length of the seam so as to be orthogonal to the seam.
Therefore, the stress applied to each precast concrete substrate in the direction intersecting the longitudinal direction can be smoothly transmitted to the reinforcing bar assembly, the reinforcing bar, and the adjacent precast concrete substrate.

[0014]

The precast synthetic void slab structure of the present invention is a precast concrete substrate fixed in advance in a direction in which the reinforcing bar assemblies intersect, for example, in a lattice shape, and the embedding material is also fixed in a position surrounded by the reinforcing bar assemblies. A floor slab is constructed by erection between beams at the construction site, arranging a plurality of reinforcing bars at the joints on this precast concrete substrate, and casting cast-in-place concrete on the precast concrete substrate.

[0015]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 (a) is a plan view of a precast composite void slab of the present invention, and FIG. 1 (b) is AA of FIG. 1 (a).
A schematic cross-sectional view and FIG. 1C are schematic cross-sectional views taken along the line BB of FIG. 2A is a detailed sectional view taken along the line CC of FIG. 1A, and FIG. 2B is a detailed sectional view taken along the line D-D of FIG. 1A. Further, FIG. 3A is a detailed sectional view taken along the line EE of FIG. 1A, and FIG. 3B is a detailed sectional view taken along the line FF of FIG.

As shown in FIGS. 1 to 3, the precast synthetic void slab of the present invention comprises three precast concrete substrates 1 (hereinafter
In this embodiment, it is simply referred to as "substrate 1". ), And lower end reinforcing bars 24 and 34 as reinforcing bars, which are placed from one substrate 1 to the other substrate 1 so as to straddle over the joint portion 5,
The lower end is embedded in the substrate 1 and is surrounded by truss bars 20 and concrete solid part reinforcing bars 30 as a reinforcing bar assembly arranged in a grid pattern in the orthogonal direction, and surrounded by these truss bars 20 and concrete solid part reinforcing bars 30. Void form 2 as an embedding material fixed at a fixed position, that is, the position of a lattice-shaped grid formed by the truss reinforcement 20 and the concrete solid reinforcement 30; the truss reinforcement 20; Rebar 30
The void form 2 is embedded, and the cast-in-place concrete 8 is cast on the substrate 1 to a predetermined thickness. In addition, in configurations other than the above, there is a lattice-shaped slab lower end bar 10 arranged in the substrate and a lattice-shaped slab upper end bar 40 arranged on the concrete solid rebar 30.

The substrate 1 is a rectangular concrete substrate manufactured in advance at a factory or a construction site. The substrate 1 includes slab lower end streaks 10 arranged in a lattice pattern, and the lower surface is formed flat.

The truss muscles 20 are fixed to the lattice muscles 23 arranged in a bifurcated manner, the upper chord muscle muscles 21 fixed by welding in the axial direction of the top of the lattice muscles 23, and the lower ends of the lattice muscles 23 by welding. And two lower chord members 22 and the lower chord member 22 and the lower end of the lattice line 23 are embedded on the slab lower end line 10 in the substrate 1. At this time, the truss streak 20 is the substrate 1
Are arranged in the longitudinal direction of. On the other hand, the concrete solid part reinforcing bar 30 has a vertically long rectangular shear reinforcing bar 33 and two bottom reinforcing bars 32 arranged at the lower two corners of the shear reinforcing bar 33 and below the lower chord member 22. And the upper end streak 31 disposed at the upper two corners of the shear reinforcing bar 33 and below the slab upper end streak 41, the lower end stirrup 32 and the lower end of the shear stiffening bar 33 are provided in the substrate 1. Buried. At this time, the concrete solid part reinforcing bars 30 are arranged in a direction orthogonal to the truss reinforcing bars 20, that is, in the lateral direction of the substrate 1.

The void mold 2 is a cube-shaped synthetic resin foam-molded product, and has a box shape with a space formed on the bottom surface side of the cube.

The lower end reinforcing bar 24 is, for example, as shown in FIG.
In (a), the seam portion 5 which is shown only partially by the diagonal lines 9 at five positions, the seam portion 5 at each of the nine positions sandwiched by the void form frame 2 and the void form frame 2 of the adjacent substrate. Then, the one substrate 1 is placed on the other substrate 1 so as to straddle the joint portion 5. On the other hand, the lower end reinforcing bar 34 is formed on the seam portion 5 which is not sandwiched by the void form frames 2 and the void form frames 2 of the adjacent substrates, and the seam portion 5 is formed from one substrate 1 to the other substrate 1.
Place it so that it straddles the top. At this time, the bottom reinforcing bar 24,
Both 34 are placed so as to be orthogonal to the joint portion 5.

Next, the procedure for constructing the precast synthetic void slab of the present invention will be described.

First, the slab lower end reinforcement 10 and the truss reinforcement 20
Of the concrete solid part rebar 30 and the lower end of the shear reinforcing bar 33 and the bottom bar 32 are embedded, and a predetermined number of the substrates 1 to which the void form 2 is fixed are installed between the beams. At this time, the upper end reinforcement 31 of the concrete solid part reinforcement 30 is not arranged yet.

Next, the lower end reinforcing bars 24 and 34 are placed on the joint portion 5 and fixed so as to straddle the joint portion 5 from one substrate 1 to the other substrate 1.

After the reinforcement of the lower end reinforcing bars 24 and 34 is completed, the upper end bars 31 of the concrete solid part reinforcing bars 30 are arranged in a direction orthogonal to the upper chord members 21 of the truss bars 20. At this time, the slab upper end reinforcement 42 is also arranged in parallel with the upper end reinforcement 31 at the same time as or before or after the reinforcement work. After that, further in a direction orthogonal to the slab upper end streak 42 and the upper end streak 31,
The slab upper end streak 41 is arranged.

After all the reinforcing work is completed, the cast-in-place concrete 8 is cast on the substrate 1 to a predetermined thickness.

[0027]

INDUSTRIAL APPLICABILITY In the precast synthetic void slab and its structure of the present invention, the reinforcing bar assemblies are arranged in two intersecting directions, and the hollow part or the concrete unfilled part is formed on the precast concrete substrate surrounded by the reinforcing bar assemblies. Since it is formed, when compared to a waffle slab or a hollow concrete slab that is a one-way slab, it is possible to obtain high rigidity with the same slab thickness and to reduce the weight of the floor slab. Therefore, the vibration of the floor slab can be suppressed, the sound insulation between the upper and lower floors is good, and the habitability is improved.

Further, in the precast synthetic void slab and its structure of the present invention, the reinforcing bar assemblies are arranged in two intersecting directions, and since stress resistance can be expected in these two directions, the side length ratio is relatively small and relatively large. Even a slab having a span of about 6 to 10 m can be realized with a smaller slab thickness than a hollow concrete slab or a waffle slab that is a unidirectional slab.

Further, in the precast synthetic void slab and its structure of the present invention, unlike the waffle slab, the bottom surface of the slab has no unevenness and is flat. There is an advantage in that it can be easily installed with high accuracy on the ceiling surface, so that these can be easily and accurately installed and sound insulation between living rooms can be easily secured.

Furthermore, since a precast concrete substrate is used and the floor slab is formed by integrating this with cast-in-place concrete, a formwork and supporting work for the floor slab can be omitted, and this precast concrete substrate can be used as a work scaffold. It is possible to improve the construction efficiency and work safety.

[Brief description of drawings]

1A is a plan view of a precast synthetic void slab of the present invention, FIG. 1B is a schematic cross-sectional view taken along line AA of FIG.
(C) is a BB sectional schematic diagram of (a).

FIG. 2A is a detailed cross-sectional view taken along the line CC of FIG.
FIG. 1B is a detailed view of the DD cross section of FIG.

FIG. 3A is a detailed cross-sectional view taken along the line EE of FIG.
FIG. 1B is a detailed view of the FF cross section of FIG.

FIG. 4A is a perspective view of a hollow concrete slab that is a conventional one-way slab, and FIG. 4B is a sectional view taken along line AA of FIG.

[Explanation of symbols]

 1 Precast Concrete Substrate 2 Void Form (Embedding Material) 5 Seam Section 8 Cast-in-Place Concrete (Concrete) 20 Truss Reinforcing Bar (Reinforcing Bar Assembly) 24 Bottom Reinforcing Bar (Reinforcing Bar) 30 Concrete Solid Part Reinforcing Bar (Reinforcing Bar Assembly) 34 Bottom Reinforcing Bar (Reinforcing Bar)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Tomita 2-5-8 Kita-Aoyama, Minato-ku, Tokyo Ma Incorporated

Claims (2)

[Claims] 1. A precast concrete substrate, a rebar assembly having a lower end embedded in the precast concrete substrate and arranged in two directions intersecting with each other, and a position surrounded by the rebar assembly on the precast concrete substrate. A precast synthetic void slab structure comprising: an embedding material fixed to the precast concrete substrate until the rebar assembly and the embedding material are embedded. 2. A precast synthetic void slab comprising a plurality of said precast synthetic void slabs installed in parallel between beams and a plurality of reinforcing bars arranged at a seam on said adjacent precast concrete substrate.