JPH0326814Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a hollow slab made of cast-in-place concrete.

This type of hollow slab is widely used in architectural structures.

[Prior Art] Hollow slabs (void slabs) are generally widely used in order to reduce the weight of the slab itself.

By the way, the hollow formwork used for conventional hollow slabs is made of cardboard or iron plate and has a circular cross section.

[Problem to be solved by the invention] However, although the hollow slab with a circular cross section has good concrete circulation around the hollow slab such as the lower end of the hollow formwork, the hollowness ratio is low, so it cannot be expected to reduce the weight of the slab much.

Further, hollow formwork made of iron plates tends to be heavy, and hollow formwork made of cardboard sometimes lifts up during concrete pouring, making it difficult to install and fix the formwork.

Furthermore, immediately after the hollow formwork is installed, the hollow formwork may be easily deformed by accidentally placing building materials on top of it or by walking on it.

The present invention was developed in view of the above-mentioned conventional circumstances, and its purpose is to ensure the hollowness ratio as much as possible in relation to the thickness of the slab, and to facilitate the installation and fixing of the hollow formwork. Furthermore, it is an object of the present invention to provide a hollow slab made of cast-in-place concrete that has no risk of deformation even if the hollow formwork is walked directly on it immediately after installation.

[Means for Solving the Problems] In order to achieve the above object, the present invention is configured as follows.

1 and 2 show the construction of a hollow slab according to the present invention.

A hollow formwork 4 having a rectangular cross section is installed between the slab upper reinforcement 2 and the slab lower reinforcement 3, and the hollow slab 1 is formed by filling the periphery with concrete 8.

The hollow formwork 4 includes a flat plate part 4a forming an upper surface and a lower surface thereof, a plurality of hollow parts 4b which laterally partition the space between the flat plate parts 4a and 4a, and each hollow part 4b formed in a rectangular cross section. 4b, and a brace-like reinforcing plate part 4c disposed obliquely into the inner part 4b.

These flat plate portions 4a, hollow portions 4b, . . . and reinforcing plate portions 4c are formed of a single piece of rigid wire mesh as shown in FIGS. 3 and 4.

[Embodiments] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

Figures 1 and 2 show the configuration of a hollow slab, in which a hollow slab 1 made of cast-in-place concrete is provided with slab top reinforcements 2, slab bottom reinforcements 3, hollow formwork 4, and connection reinforcements 5. ing.

The slab top reinforcements 2 and the slab bottom reinforcements 3 are arranged in a grid pattern over the entire slab, and the slab top reinforcements 2 and the slab bottom reinforcements 3 are connected by a plurality of connecting reinforcements 5.

In the space sandwiched between the connecting bars 5 and 5 between the slab upper reinforcement 2 and the slab lower reinforcement 3, hollow formwork 4 is installed along the longitudinal direction of the slab at regular intervals in the width direction of the slab. There is.

As shown in the figure, the hollow formwork 4 includes a flat plate part 4a forming an upper surface and a lower surface thereof, and hollow parts 4b, 4 disposed on both sides of the flat plate part 4a and having a rectangular cross section.
b, and a brace-like reinforcing plate portion 4c disposed diagonally within the hollow portions 4b, 4b,
The hollow parts 4b, 4b and the reinforcing plate part 4c are also continuous in the longitudinal direction (front-back direction in the figure) of the flat plate part 4a.

Flat plate part 4a and hollow part 4b forming hollow formwork 4
The reinforcing plate portion 4c is formed by bending a piece of extremely rigid lath wire mesh as shown in FIG. 4 as shown in FIG.

A large number of reinforcing ribs 6 which are continuous in the width direction or longitudinal direction and have a V-shaped cross section or a U-shaped cross section are formed on this lath wire mesh.

Further, the hollow formwork 4 can also be formed of extremely rigid wire lath, metal lath, punched metal, or the like, in addition to lath wire mesh.

Furthermore, the cross-sectional shape of the hollow formwork 4 is shown in FIGS.
It can also be formed into the shape shown in the figure.

The hollow formwork 4 can be assembled both in a factory and on site.

Next, installation of the hollow formwork 4 will be explained.

The hollow formwork 4 is installed on a slab formwork (not shown) via a spacer, and thereby the hollow formwork 4
The required concrete cover thickness is ensured between the concrete cover and the slab formwork.

This hollow formwork 4 is tightly tied and fixed to the slab upper end reinforcement 2 and the slab lower end reinforcement 3 with binding wires 7.

After the formwork is assembled, concrete 8 is filled around the hollow formwork 4, and the hollow formwork 4 is filled with slab top reinforcement 2,
It is completely integrated with the slab bottom reinforcement 3.

The concrete 8 used has as low a slump as possible so as not to leak into the mesh of the hollow formwork 4 during pouring and compaction using a vibrator.

Alternatively, a thin vinyl sheet may be wrapped around the hollow formwork 4 to prevent concrete from leaking.

As explained above, according to this embodiment, since the hollow formwork 4 is formed to have a rectangular cross-section, the hollowness ratio can be maximized in relation to the thickness of the slab, and the weight of the slab can be reduced.

In addition, since the hollow formwork 4 is made of rigid wire mesh, concrete 8 can be poured while visually checking the filling state at the bottom end of the formwork. Even if it is a frame, it is possible to reliably fill the concrete 8 to every corner around the hollow formwork 4.

In addition, the hollow formwork 4 is made of rigid wire mesh, and brace-like reinforcing plate parts 4c are arranged in the left and right hollow parts 4b, so that the rigidity of the hollow formwork 4 as a whole is significantly increased. There is no risk of deformation even if a person walks on the hollow formwork 4 or places construction materials on it.

Furthermore, since the hollow formwork 4 is formed from a single piece of rigid wire mesh, it is extremely easy to manufacture and can be mass-produced.

[Effects of the invention] As explained above, according to the invention, since the hollow formwork is formed to have a rectangular cross section, the hollowness ratio can be maximized in relation to the thickness of the slab, and the weight of the slab can be reduced. .

In addition, since the hollow formwork is made of rigid wire mesh, concrete can be poured while visually checking the filling condition at the bottom of the formwork.For this reason, it is possible to pour concrete while visually checking the filling condition at the bottom of the formwork. Even if there is a problem, it is possible to reliably fill every corner of the hollow formwork with concrete.

In addition, the hollow formwork is made of rigid wire mesh,
A reinforcing plate is placed in the hollow part of the hollow formwork, so the rigidity of the entire hollow formwork is significantly increased.
As a result, there is no risk of deformation even if people walk on the hollow formwork or building materials are placed on it.

Furthermore, since the hollow formwork is formed from a single piece of rigid wire mesh, it is extremely easy to manufacture and can be mass-produced.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of a hollow slab according to the present invention, Figures 3 and 4 are plan views of lath wire mesh, and Figures 5 and 6 are cross-sectional views showing other embodiments of the hollow formwork. Figure. 1...Hollow slab, 2...Slab top reinforcement, 3...
...Slab bottom reinforcement, 4...Hollow formwork, 4a...Flat plate part, 4b...Hollow part, 4c...Reinforcement plate part, 5...
Connection bar, 6... Reinforcement rib, 7... Binding wire, 8...
concrete.

Claims (1)

[Scope of Claim for Utility Model Registration] In a hollow slab made of cast-in-place concrete, in which a hollow formwork 4 with a rectangular cross section is installed between the slab upper reinforcement 2 and the slab lower reinforcement 3, and the surrounding area is filled with concrete 8. , the hollow formwork 4 has a flat plate part 4a that forms the upper and lower surfaces thereof, a plurality of hollow parts 4b that laterally partitions the space between the flat plate parts 4a and 4a, and is formed in a rectangular cross section, and each hollow It has a brace-like reinforcing plate part 4c disposed obliquely into the part 4b, the flat plate part 4a, the hollow part 4b... and the reinforcing plate part 4c.
is a hollow cast-in-place concrete slab that is formed from a single piece of rigid wire mesh.