JP2000127133A - Void form for precast concrete and semi-precast concrete composite slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a form easily, to reduce a place for storage, and also to enable also visual check of the states of wiring, buried hardware, etc., under the form from outside and, moreover, to reinforce the inside of a hollow part and thereby to prevent occurrence of a crack or the like, by forming a void form out of perforated boards constituted of metallic thin boards. SOLUTION: A semi-precast concrete slab (semi-Pea slab) 2 having a smaller thickness than a slab to be formed is placed. Next, truss rods 3 are planted fixedly so that the upper parts thereof are projected above the semi-Pea slab 2, and further a void form 4 is set thereon and fixed. Besides, necessary reinforcing bars 5 are arranged in the semi-Pea slab 2. The void form 4 is formed of perforated boards constituted of bendable metallic thin boards and it is formed in the shape of a box which is composed of a top board part 4a, side board parts 4b surrounding the four sides and fixing board parts 4c formed by bending the respective lower ends of the side board parts 4b outward and of which the lower side is opened. This form is fixed by driving anchorage metals 6 in the semi-Pca slab 2 through holes 4d of the fixing board parts 4c before the semi-Pca slab is cured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a void formwork for precast concrete and a semi-precast concrete composite plate.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a void slab made of precast concrete (hereinafter, referred to as PCa), there is, for example, a method shown in FIGS.

[0003] In this molding method, first, in a factory, FIG.
As shown in FIG. 1, a semi-precast concrete plate (hereinafter, referred to as a half-PCa plate) 101 having a thickness smaller than the thickness to be formed is cast, a truss bar 102 is projected, and a half-PCa plate is formed.
On the upper surface of the plate 101, a plurality of void forms 103 are arranged at predetermined positions at appropriate intervals, and
The fixing part 105 fixes the half-PCa plate 101 to the half-PCa plate 101 to form a semi-precast concrete composite plate (hereinafter referred to as a half-PCa composite plate) 106 as shown in FIG. As shown in the figure, concrete 107 is cast on a semi-PCa composite plate 106 to form a void slab 109 made of PCa having a hollow portion 108 in the body. Such a void slab 109 is often used as a lightweight concrete plate because it has a hollow portion 108 in the body.

As shown in FIG. 5 to FIG. 8, the void mold 103 has an upper wall 110 and a side wall 111 and is formed with a large number of hollow portions 108 having a lower surface opening in the body. In some cases, it is molded into a void form.

[0005]

Since the conventional void mold 103 is made of a foamed resin, it is lightweight, and can be easily cut to the dimensions of the PCa plate to be manufactured. There is an advantage that the followability to the shape of the plate is easy. On the other hand, if the cut is taken along the line AA in FIG. 104 part is cut off and the void form 10
3 becomes difficult to fix to the half-PCa plate 101, and there is a problem that it is displaced or detached during conveyance, and further, the side of the hollow portion 108 is opened as shown in FIG. From B, concrete 10 to be cast on site
7 wraps around the inside of the hollow portion 108 and is filled, and there is a problem that lightness is impaired.

Therefore, there is a problem that it is difficult to cut the void mold 103 to obtain a free shape. Further, since the void form 103 has a three-dimensional shape having a considerably large volume, a large storage space is required to store a large number of the three-dimensional shapes, which is inconvenient to store.

Further, since the void mold 103 is an opaque body, it is not possible to externally view the state of the wiring, the embedded metal, and the like located below the void mold 103. Therefore, there is also a problem that it is not possible to reconfirm the wiring and the buried metal fittings at the portion after the void form 103 is fixed.

Accordingly, an object of the present invention is to provide a void formwork for precast concrete and a semi-precast concrete composite board which solve the above-mentioned problems.

[0009]

According to a first aspect of the present invention, a void form is placed and fixed on an upper surface of a semi-precast concrete plate, and then the half-precast concrete plate is fixed. A void formwork used for molding concrete on a concrete plate to form a hollow concrete plate, wherein the void is formed by a perforated plate made of a thin metal plate. It is a formwork.

According to a second aspect of the present invention, in the first aspect, a top plate portion, a side plate portion surrounding four side portions,
A void mold frame for precast concrete, comprising a fixing plate portion formed by bending a lower end of each side plate portion outward, and formed in a box shape with an open lower surface.

According to a third aspect of the present invention, there is provided the void for precast concrete according to the first or second aspect, wherein a metal lath is used as the perforated plate made of the metal thin plate. It is a formwork.

According to a fourth aspect of the present invention, there is provided a semi-precast concrete composite wherein a void form formed of a perforated plate made of a metal thin plate is placed and fixed on an upper surface of a semi-precast concrete plate. It is a board.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the void formwork includes a top plate portion, side plate portions surrounding four side portions, and a lower end of each side plate portion disposed outside. A semi-precast concrete composite plate comprising a bent bent fixing plate portion and formed in a box shape with an open lower surface.

According to a sixth aspect of the present invention, there is provided a semi-precast concrete composite according to the fourth or fifth aspect, wherein a metal lath is used as the perforated plate made of the metal thin plate. It is a board.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on an embodiment shown in FIGS. FIG. 1 is a longitudinal sectional view of a semi-precast concrete composite board (hereinafter, referred to as a semi-PCa composite board) formed in a factory.

In the factory, a semi-precast concrete plate (hereinafter, referred to as a half-PCa plate) 2 having a thickness smaller than the thickness to be formed is cast at the factory, and the semi-PC
A connecting bar, for example, a truss bar 3, is placed on the a
It is constructed by projecting on the Ca plate 2 and solid-fixing, and further mounting and fixing the void form 4 on the semi-PCa plate 2. Also, necessary reinforcing bars 5 are arranged in the half PCa plate 2.

A plurality of truss bars 3, which are the connecting bars, are arranged in parallel at predetermined intervals, for example, as in the conventional case shown in FIG. The void form 4 is formed of a perforated plate made of a bendable metal thin plate, and as shown in FIG. 2, a top plate 4a and a side plate 4 surrounding four sides.
b and a fixing plate portion 4c formed by bending the lower end of each side plate portion 4b outward, and is formed in a box shape with an open lower surface. 4d indicates a hole. This void form 4 is formed by bending a flat plate having the shape shown in FIG. 3 at each fold line portion 4e to form the shape shown in FIG. As the perforated metal plate forming the void form 4, a thin perforated plate having a thickness of up to about 3.2 mm is used. For example, a metal lath, a wire mesh, a wire mesh, a wire lath, or the like is used. Particularly, a metal lath is desirable. Further, the mesh used is such that the coarse aggregate of the poured concrete does not pass and the ready-mixed concrete does not pass. For example, the mesh size is 12 × 17 mm.
８8 × 14 mm is used.

Then, the void form 4 is placed on the half-PCa plate 2 while the half-PCa plate 2 is not yet cured, and fixing fixtures 6 such as concrete nails are inserted through the holes 4d of the fixing plate portion 4c. Driving the semi-PCa plate 2 with the void form 4
Is fixed. As shown in FIG. 1, a plurality of the void forms 4 are arranged and fixed in the space between the adjacent connecting bars 3, and a plurality of the void forming frames 4 are arranged at appropriate intervals in the axial direction of the connecting bars 3. Fix it.

The half-PCa plate 2 is cured and cured to obtain a half-PCa composite plate 1. The truss-like connecting bars are also called omnia bars, and the semi-PCa composite plate 1 is also called an omnia void plate.

Then, the semi-PCa manufactured at the factory
The composite board (Omnia void board) 1 is transported to the construction site, and in the site, as shown in FIG. Set up. At the time of casting the cast-in-place concrete 7, since the size of the hole 4d of the void form 4 is set as described above, the cast-in-place concrete 7 does not flow into the void form 4, and the void form A hollow portion 8 is formed in the frame 4. Therefore, by hardening the cast-in-place concrete 7, the PCa board 1 having the hollow portion 8 in the body
0 is formed. Further, the semi-PCa plate 2 and the cast-in-place concrete 7 are firmly connected by the connecting bars 3 and integrated.

Further, since the void form 4 is formed of a perforated plate as described above, after the void form 4 is fixed to the semi-PCa plate 2, before the cast-in-place concrete 7 is cast, The wiring, the embedded metal, and the like located below the void form 4 can be seen from the hole 4d of the void form 4, and the situation such as forgetting the wiring or the embedded metal can be confirmed.

Since the void form 4 is formed by bending a perforated plate made of a thin metal plate, the perforated plate of the material is cut into a desired size and each side is bent. By forming, the void form 4 of a desired size can be easily formed. Therefore, in the factory, the void form 4 can be easily formed in a box shape having a desired size in accordance with the dimension of the half PCa plate 2 to be formed.

For example, when it is desired to form a void formwork smaller than the void formwork 4 formed from a material having a cut size as shown in FIG. 3, each piece of the material shown in FIG. By cutting, a small void form having side plates in all directions can be easily formed.

Therefore, the problem that the hollow portion 108 is opened can be solved by cutting and reducing the size as in the case of the conventional void mold 103 made of a foamed resin. Further, as shown in FIG.
Since it can be unfolded and stored in the form of a flat plate, a large number of these can be stacked and stored, so that the number of storage locations is extremely reduced as compared with the conventional void form 103.

Further, after the cast-in-place concrete 7 is cast, the concrete 7 engages with the hole of the void form 4, and the inner surface of the hollow section 8 is reinforced by the void form 4. Cracks can be prevented from occurring.

Although the PCa plate of the present invention is mainly used as a void slab, it can be used as another hollow PCa plate.

[0027]

According to the present invention, since the void form is formed of a perforated plate made of a thin metal plate, the plate of the material is cut and bent to form a box-shaped void mold having a desired size and shape. The frame can be easily formed, and the problem caused by cutting such as the conventional foamed resin can be solved.

Further, since it is a perforated plate, it is possible to easily fix the void form to the semi-PCa plate by using the holes. Furthermore, the state before assembling as a void form is made into a developed flat plate shape, so that when storing a large number of void forms, the storage space can be reduced as compared with the conventional foam resin.

Further, even after the void form is fixed on the semi-precast concrete plate, since the void form is a perforated plate, wirings, embedded metal parts, etc. under the void form are passed through the holes. Can be visually checked from the outside, and it is possible to reconfirm whether the wiring, the embedded metal, or the like has been forgotten.

Furthermore, cast-in-place concrete is engaged with the hole of the void form, and the inner surface of the hollow portion is reinforced, so that cracks can be prevented from occurring.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a semi-precast concrete composite plate of the present invention.

FIG. 2 is a perspective view showing an embodiment of the void formwork of the present invention.

FIG. 3 is a development view of the void formwork of FIG. 2;

FIG. 4 is a longitudinal sectional view showing a concrete plate formed using the semi-precast concrete composite plate of the present invention.

FIG. 5 is a longitudinal sectional view showing a conventional semi-precast concrete composite plate.

FIG. 6 is a perspective view showing a conventional void form, viewed from the front side.

FIG. 7 is a perspective view of the void formwork of FIG. 6 as viewed from the back side.

FIG. 8 is a perspective view of the semi-precast concrete composite board of FIG. 5;

FIG. 9 is a longitudinal sectional view showing a conventional concrete plate formed using the semi-precast concrete composite plate of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semi precast concrete composite board 2 ... Semi precast concrete board 3 ... Connecting bar 4 ... Void formwork 4a ... Top plate part 4b ... Side plate part 4c ... Fixing plate part 6 ... Fixing metal

Claims (6)

[Claims] 1. A void mold used for forming a hollow concrete plate by placing and fixing a void formwork on the upper surface of a semi-precast concrete plate, and thereafter casting concrete on the semi-precast concrete plate. A void formwork for precast concrete, wherein the formwork is made of a perforated plate made of a thin metal plate. 2. A top plate, a side plate surrounding four sides,
The void formwork for precast concrete according to claim 1, comprising a fixing plate portion having a lower end of each side plate portion bent outward and formed in a box shape with an open lower surface. 3. The void formwork for precast concrete according to claim 1, wherein a metal lath is used as the perforated plate made of a metal thin plate. 4. A semi-precast concrete composite plate characterized by mounting and fixing a void form formed of a perforated plate made of a thin metal plate on the upper surface of a semi-precast concrete plate. 5. A box comprising a top plate portion, side plate portions surrounding four side portions, and a fixing plate portion formed by bending a lower end of each side plate portion outward, wherein the bottom surface of the void form frame is opened. The half precast concrete composite plate according to claim 4, wherein the composite plate is formed in a mold. 6. The semi-precast concrete composite plate according to claim 4, wherein a metal lath is used as the perforated plate made of a metal thin plate.