JP2022045148A - Form for temporary opening - Google Patents

Abstract

To provide a form for a temporary opening capable of easily mounting a bottom plate form for closing the temporary opening provided in the construction work of a reinforced concrete building.SOLUTION: A form for a temporary opening is constituted of: a side face part 2 forming an outer periphery of a temporary opening 10; an upper cover part 3 attached to an upper part of the side face part 2 and securing an upper cover thickness of the side face part 2 when concrete is placed; a lower cover part 4 attached to a lower part of the side face part 2 and securing a lower cover thickness of the side face part 2 when concrete is placed; an anchoring bar 5 penetrating the inside of the temporary opening 10 and integrating the temporary opening 10 with the surrounding concrete; and a lid 6 closing the lower end of the temporary opening 10. The side face part 2 is connected at four corners by corner connecting members 13, and the corner connecting member 13 is provided with an insert 24 through which a bolt 35 can be inserted from below the temporary opening 10; the lid 6 has bolt holes 32 for bolts which can be fixed to the insert 24 in alignment with the position of the insert 24.SELECTED DRAWING: Figure 5

Description

The present invention relates to a formwork for a temporary opening that forms a temporary opening for transporting construction materials and the like in a floor slab of a reinforced concrete structure.

Conventionally, in the construction work of a reinforced concrete condominium or the like, a temporary opening is formed in a floor slab by using a formwork for a temporary opening in order to carry in construction materials or the like. This temporary opening is closed with concrete after the material is brought in, and the floor slab is completed.

When closing the temporary opening, the bottom of the temporary opening is covered with a bottom plate formwork, and then concrete is poured. As a method of attaching the bottom plate formwork, for example, Patent Document 1 describes a method of supporting the bottom plate formwork with a pipe support from the lower floor.

However, the pipe support needs to be installed for a certain period of time, during which the work space on the lower floor becomes narrower. Further, when the temporary opening is provided on the lower floor at the same position as the temporary opening, the bottom plate form cannot be fixed by the pipe support.

As a method of attaching the bottom plate formwork in such a case, in Patent Document 1, a steel pipe or the like is arranged so as to straddle the upper end of the temporary opening, and a number wire or the like is bound to the steel pipe to suspend the bottom plate formwork. Is also disclosed.

Alternatively, conventionally, an insert is embedded in a floor slab and a bottom plate formwork is attached.

Japanese Unexamined Patent Publication No. 2001-173230

However, all of the methods described in Patent Document 1 require special and troublesome work, and a specialized worker is required to attach the bottom plate formwork.

Further, when the insert is embedded in the floor slab, the work of burying the insert is troublesome. Moreover, in order to prevent the floor slab from splitting, it is necessary to install the insert at a position some distance from the temporary opening, and it is necessary to make the size of the bottom plate formwork considerably larger than the opening. When the size and weight of the bottom plate formwork increase, the labor required for transportation and work increases, and depending on the weight of the concrete that closes the temporary opening, there arises a problem that the deformation of the bottom plate formwork becomes excessive.

An object of the present invention is a temporary opening to which a bottom plate formwork can be easily attached without requiring a specialized worker who requires special skills when closing the temporary opening provided in the construction work of a reinforced concrete structure. To provide a formwork.

In order to solve the above problems, the present invention is a formwork for a temporary opening for forming a temporary opening in a floor slab of a reinforced concrete structure under construction, and a side surface forming the outer periphery of the temporary opening. The upper cover portion, which is attached to the upper part of the side surface portion and secures the upper cover thickness of the side surface portion when concrete is placed, and the upper cover portion which is attached to the lower portion of the side surface portion and is attached to the lower part of the side surface portion when concrete is placed. A lower cover portion that secures the lower cover thickness, a fixing bar that penetrates the inside of the temporary opening and integrates the temporary opening with the concrete around it, and a lid that closes the lower end of the temporary opening. The side surface portion is connected at four corners by a corner connecting member, the corner connecting member is provided with an insert through which a bolt can be inserted from below the temporary opening, and the lid is at the position of the insert. Provided is a form for a temporary opening, characterized in that a bolt hole for a bolt that can be fixed to the insert is formed in accordance with the above.

The lid has a flat plate portion that closes the entire temporary opening, and a rib-shaped frame portion provided along the opposite sides in the longitudinal direction of the flat plate portion, and the bolt hole is formed with the flat plate portion. It is preferably formed so as to penetrate the frame portion.

It is preferable that the insert is provided inside the upper end side of the temporary opening, and the upper end side of the temporary opening is larger than the lower end side.

According to the present invention, in a temporary opening provided in a building work of a reinforced concrete structure, the lower end is not required and the lower end is not disturbed to the work space on the lower floor without requiring a specialized worker having special skills. Can be closed.

It is a top view which shows the installation example of the formwork for a temporary opening which concerns on embodiment of this invention. It is a perspective view which shows the example of the formwork for a temporary opening which concerns on embodiment of this invention. It is a perspective view which shows the example of the side surface part of the formwork for a temporary opening of FIG. It is a bottom view which shows the example of the cover of the formwork for a temporary opening which concerns on embodiment of this invention. It is explanatory drawing which shows the state at the time of use of the form for temporary opening which concerns on embodiment of this invention, (a) is the state which the top and bottom of the temporary opening are open, (b) is below the temporary opening. Indicates a state in which the lid is fixed. It is explanatory drawing which shows the state at the time of use of the form for temporary opening which concerns on embodiment of this invention, (a) is the state which the top and bottom of the temporary opening are open, (b) is above the temporary opening. Indicates the state in which the lid is installed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

The present invention is a formwork used for a temporary opening provided for transporting construction materials and the like in a reinforced concrete floor slab under construction. FIG. 1 shows an example in which a formwork for a temporary opening according to an embodiment of the present invention is installed on a floor slab of a reinforced concrete structure under construction, and FIG. 2 shows an example for a temporary opening according to the present embodiment. The schematic structure of the formwork 1 is shown. After finishing its role, the temporary opening is closed by closing the lower end with a lid and placing post-cast concrete in the formwork.

As shown in FIG. 1, reinforcing bars necessary for designing as a floor slab are arranged around the temporary opening 10, and the form 1 for the temporary opening is arranged at a position where the temporary opening 10 is formed. .. Normally, a reinforcing bar 9 that replaces the reinforcing bar that is lost due to the temporary opening 10 is arranged on the outer peripheral side of the temporary opening formwork 1. As shown in FIG. 2, the formwork 1 for a temporary opening according to the present embodiment has a side surface portion 2, an upper cover portion 3, a lower cover portion 4, and a fixing bar 5. In FIG. 2, the description of the upper cover portion 3 is omitted for the two sides on the front side. Further, the lid 6 is not shown in FIG.

The side surface portions 2 are arranged on each of the four sides that are the outer periphery of the temporary opening 10. As shown in FIG. 3, for example, the side surface portion 2 is integrally formed with a mesh-shaped dam 11 and a convex rib 12 extending in the vertical direction alternately. The convex ribs 12 project inward on each side of the temporary opening formwork 1. The side surface portions 2 arranged on all sides are connected by the corner connecting member 13. As the material of the side surface portion 2, for example, a hot-dip galvanized steel sheet having a thickness of about 0.4 mm is used, and the dam 11 is not limited to a mesh shape but may be a flat plate shape. Since the convex rib 12 is provided on the side surface portion 2, high rigidity can be ensured, and deformation when receiving lateral pressure during concrete placement can be suppressed. Further, the contact area between the pre-cast concrete around the temporary opening and the post-cast concrete cast in the temporary opening can be increased to enhance the integrity. The vertical dimension of the side surface portion 2 is determined according to the thickness of the floor slab, and is, for example, 90 mm or more. By installing a waterproof rubber or the like on the upper part of the side surface portion 2 over the entire circumference, it is possible to obtain waterproof performance after closing the temporary opening 10.

The upper cover portion 3 is provided to secure the upper cover dimension of the side surface portion 2. In the present embodiment, the upper cover portion 3 extends upward and diagonally toward the outside of the temporary opening 10, and is provided over the entire outer periphery of the temporary opening 10. Since it extends diagonally upward, it can be easily removed after placing concrete in the formwork. The material of the upper cover portion 3 is not particularly limited, and for example, an iron plate or the like is used. The upper cover portion 3 is removed after the concrete is placed in the formwork for the temporary opening.

The lower cover portion 4 is provided to secure the lower cover dimension of the side surface portion 2, and is provided at the lower portion of the side surface portion 2. The lower cover portion 4 is provided with, for example, a spacer 21 for raising the side surface portion 2 from the installation position, and a mesh-shaped control member 22 for preventing the precast concrete from entering the temporary opening. In the present embodiment, the control member 22 is attached so as to cover the entire height direction of the spacer 21, and extends toward the inside of the temporary opening and inward of the convex rib 12 of the side surface portion 2. It is provided in. The control member 22 is not limited to the mesh shape, but may be a flat plate-shaped steel plate. The lower cover portion 4 does not need to be removed after the concrete is placed, and is buried as it is. When placing concrete in the temporary opening by installing the lower cover portion 4 in this way so that the cross section of the temporary opening after placing the pre-cast concrete becomes smaller toward the lower side. , Prevents concrete from falling off and can reliably fill every corner. The control member 22 is attached, for example, by welding to the upper part of the spacer 21.

The fixing bar 5 is configured by, for example, crimping a steel pipe sleeve 23 as a fixing member to both ends of a different diameter reinforcing bar of D13. Both ends are not limited to a sleeve shape as long as they can be fixed to the corner connecting member 13, but a shape that can be installed without disturbing the reinforcement arrangement around the temporary opening is preferable. The fixing bar 5 penetrates the inner peripheral side of the temporary opening 10 along the side surface portions 2 on all sides, and protrudes outward by a predetermined length from the temporary opening formwork 1. As a result, after the concrete is placed, the inside of the formwork 1 for the temporary opening and the slab around the inside are integrated. As a result, the bending moment generated at the place where the temporary opening 10 is filled can be transmitted to the periphery, and the bending moment generated in the slab can be resisted instead of the slab reinforcing bar that is lost due to the provision of the temporary opening 10. ..

The four corners of the side surface portion 2 are connected by the corner connecting member 13. The corner connecting member 13 is provided with an insert 24 so that a bolt can be inserted from below. The insert 24 is provided at a position inside the upper end of the temporary opening 10 formed in a state where the temporary opening formwork 1 is installed at the site. The formwork 1 for a temporary opening configured as described above is, for example, assembled at a factory, carried into a site, and installed at a construction site.

The insert 24 is used when the temporary opening 10 has finished its role of transporting materials and is closed, and when the lid 6 for closing the lower end of the temporary opening 10 is attached before placing concrete. FIG. 4 shows an example of the lid 6 according to the present embodiment. The lid 6 has a flat plate portion 31 having a size that covers the entire temporary opening 10, and bolt holes 32 are formed in the vicinity of the four corners of the flat plate portion 31 corresponding to the positions of the inserts 24 of the corner connecting member 13. There is. Further, a frame portion 33 having an L-shaped angle is fixed so as to connect the bolt holes 32 to each other near the outer periphery of the opposite sides of the flat plate portion 31 in the long side direction. The frame portion 33 is not limited to an L-shaped angle, but is provided in a rib shape in order to improve the rigidity of the flat plate portion 31, and is fixed to the flat plate portion 31 by welding, for example. The bolt holes 32 formed in the flat plate portion 31 are also formed at the same positions in the frame portion 33, that is, the bolt holes 32 penetrate the flat plate portion 31 and the frame portion 33. Further, in the present embodiment, in order to increase the rigidity of the flat plate portion 31 and prevent deformation when a load of concrete is applied, the reinforcing material 34 made of an L-shaped angle is appropriately formed in the short side direction of the flat plate portion 31. However, it is fixed by welding or screwing.

Hereinafter, how to use the lid 6 will be described.

When the lid 6 is attached to the lower end side of the temporary opening 10 after finishing the role of transporting materials, the surface of the lid 6 to which the frame portion 33 is attached faces downward as shown in FIG. 5A. Then, the bolt hole 32 of the lid 6 and the position of the insert 24 are aligned with each other, and the bolt 35 is screwed into the insert 24 from below the lid 6 to fix the lid 6 as shown in FIG. 5 (b). By providing inserts 24 in advance at the four corners of the temporary opening formwork 1, the lid 6 can be easily attached without requiring special skills and without the need for pipe supports or the like that limit the space on the lower floors. be able to.

Further, by providing the rib-shaped frame portion 33 on the lid 6 as in the present embodiment, the rigidity of the lid 6 is improved, and the lid 6 is deformed by the weight of the concrete on the lower end side of the temporary opening 10. Can be prevented. Further, since the bolt hole 32 penetrates the flat plate portion 31 and the frame portion 33, the lid 6 can be stably and firmly fixed. Therefore, the lid 6 can be used as it is as a bottom plate formwork. Further, the lid 6 is preferably lightweight in consideration of labor for carrying and installing, but by providing the frame portion 33 and the reinforcing material 34, the strength and rigidity required for the flat plate portion 31 can be obtained. Since it can be reduced, the plate thickness can be made thin and weighable. The material of the flat plate portion 31 is preferably made of lightweight resin, but may be made of wood or iron. Further, the frame portion 33 is preferably made of iron because it requires high strength and rigidity, but may be made of resin as long as it satisfies the required strength and rigidity.

Further, if the insert 24 is installed between the upper end and the lower end of the temporary opening 10, particularly at the lower end of the corner connecting member 13, the lid 6 on the lower end side can be fixed at a position close to the lid 6. Deformation of the lid 6 due to the weight of concrete can be reduced.

On the other hand, it is preferable to close the upper end side of the temporary opening 10 in consideration of the workability of the building work, except for the curing period of the concrete placed in the temporary opening 10 and the transportation of construction materials. In the present embodiment, as described above, the upper cover portion 3 extends diagonally toward the outside of the temporary opening 10, and the control member 22 of the lower cover 4 extends toward the inside of the temporary opening 10. It is provided. Therefore, as shown in FIG. 6A, the opening width W1 at the upper end of the temporary opening 10 is formed to be larger than the opening width W2 at the lower end. Then, by setting the position of the insert 24 to be inside the side surface position of the upper end of the temporary opening of the upper cover portion 3, the frame portion 33 is placed on the upper end side of the temporary opening 10 when the lid 6 is placed. Can be stored inside. Therefore, the lid 6 that closes the lower end side can also be used when temporarily closing the upper end side of the temporary opening 10. In that case, as shown in FIG. 6B, the lid 6 is simply placed so that the frame portion 33 fits inside the temporary opening 10 with the side to which the frame portion 33 is attached facing downward. It's fine. Even if the lid 6 is displaced in the horizontal direction by making the size so that the lid 6 does not fall into the temporary opening 10 even if the position is displaced until the frame portion 33 comes into contact with the side surface of the temporary opening 10. By catching the frame portion 33 on the side surface of the temporary opening 10, further deviation can be prevented. Therefore, the upper end side does not require fixing means such as bolts, and it does not take time to attach / detach, so that the temporary opening 10 can be easily closed temporarily.

When the lid 6 is placed on the upper part of the temporary opening 10, it is desirable that the lid 6 does not protrude significantly from the upper part of the temporary opening 10 because the workability is lowered if a step is generated. According to the present embodiment, the step can be minimized by fitting the frame portion 33 downward into the inside of the opening and reducing the plate thickness of the flat plate portion 31.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and of course, the technical scope of the present invention also includes them. It is understood that it belongs to.

The present invention can be applied to a formwork for a temporary opening used when forming a temporary opening in a floor slab of a reinforced concrete structure.

1 Formwork for temporary opening 2 Side surface part 3 Upper cover part 4 Lower cover part 5 Fixing bar 6 Lid 10 Temporary opening 11 Weir plate 12 Convex rib 13 Corner connecting member 21 Spacer 22 Containing member 23 Steel pipe sleeve 24 Insert 31 Flat plate 32 Bolt hole 33 Frame 34 Reinforcing material 35 Bolt

Claims (3)

A formwork for temporary openings for forming temporary openings in the floor slabs of reinforced concrete structures under construction.
The side surface portion forming the outer circumference of the temporary opening and the side surface portion
An upper cover portion that is attached to the upper part of the side surface portion and secures the upper cover thickness of the side surface portion when concrete is placed.
A lower cover portion that is attached to the lower part of the side surface portion and secures the lower cover thickness of the side surface portion when placing concrete.
A fixing bar that penetrates the inside of the temporary opening and integrates the temporary opening with the concrete around it.
A lid that closes the lower end of the temporary opening,
Consists of
The four corners of the side surface portion are connected by corner connecting members, and the corner connecting member is provided with an insert through which a bolt can be inserted from below the temporary opening.
The lid is a form for a temporary opening, characterized in that a bolt hole for a bolt that can be fixed to the insert is formed in accordance with the position of the insert. The lid has a flat plate portion that closes the entire temporary opening, and a rib-shaped frame portion provided along the opposite sides in the longitudinal direction of the flat plate portion, and the bolt hole is the flat plate portion. The form for a temporary opening according to claim 1, wherein the form is formed so as to penetrate the frame portion. The formwork for a temporary opening according to claim 1 or 2, wherein the insert is provided inside the upper end side of the temporary opening, and the upper end side of the temporary opening is larger than the lower end side. ..

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