JP2022075027A - Sheathing board for concrete form and sheathing board panel for the concrete form - Google Patents

Abstract

To secure a bond strength between a sheathing board and a reinforcing bar which can satisfactorily weld the sheathing board and the reinforcing bar.SOLUTION: A sheathing board 10 for a concrete form has a plurality of ribs 11 and 11A arranged at predetermined intervals, and a mesh part 12 that is provided between the ribs 11 and 11A and is provided with a plurality of meshes 15. The ribs 11 and 11A have such bent shapes as to project inward (rear side) in their cross-sectional shapes. The mesh part 12 is provided with a welding area 16. The reinforcing bar 20 is fixed to the welding area 16 from outside (surface side) by welding.SELECTED DRAWING: Figure 2

Description

The present invention relates to a weir for a concrete formwork and a panel using the same.

Generally, in the construction of a concrete structure, a weir such as plywood or a metal plate is stretched to form a formwork, concrete is cast in the formwork, and the cast concrete is hardened before the formwork. Is being dismantled. The dismantling of this formwork is a factor that prolongs the construction period.

Therefore, in recent years, throw-away formwork that does not need to be dismantled has been used. After the cast concrete is hardened, the waste formwork is integrated into the concrete structure as a component thereof. As a result, labor can be saved and the construction period can be shortened as compared with the case of using a formwork that needs to be dismantled.

The following Patent Document 1 discloses a dam panel forming a side surface portion of a waste formwork used for constructing a concrete structure. In this dam panel, a plurality of vertically extending reinforcing bars arranged at predetermined intervals, a plurality of horizontally extending reinforcing bars arranged at predetermined intervals, and a wire mesh sandwiched between these vertical reinforcing bars and horizontal reinforcing bars are provided. Have. The joint between the wire mesh and the reinforcing bar is welded.

Japanese Unexamined Patent Publication No. 2002-309699

In the dam panel of Patent Document 1, the wire mesh joined to the reinforcing bar by spot welding or the like is formed of fine striations. Therefore, it is difficult to set welding conditions such as pressing force, current value, energization time, and electrode shape at the time of welding. If the welding is excessive, the striations will melt down, and if the welding is insufficient, the joint strength between the wire mesh and the reinforcing bar will be insufficient, and the quality of the dam panel will not be stable.

When concrete is placed in a formwork composed of a dam panel having insufficient joint strength between the wire mesh and the reinforcing bar, there is a risk that the wire mesh will bend due to the placing pressure and the joint with the reinforcing bar will be disconnected. If the joint with the reinforcing bar is broken and the wire mesh is bent, there is a risk that the tolerance of the cross-sectional dimensions of the skeleton of the concrete structure will be exceeded.

Further, in the dam panel of Patent Document 1, since the wire mesh is provided in a plane with respect to the axial direction of the reinforcing bar, the joint strength between the wire mesh and the reinforcing bar is weak against the in-plane force of the wire mesh. For example, when a force is applied to the net body from a direction intersecting the in-plane direction of the wire mesh, the wire mesh is linearly displaced toward the portion where the force is applied, and a dent is likely to occur in that portion.

The present invention has been made to solve at least one of the above-mentioned problems, and the concrete formwork weir according to one aspect of the present invention has a plurality of support columns arranged at predetermined intervals and the above-mentioned support columns. It is equipped with a mesh part provided between them and a plurality of meshes are arranged.
The mesh portion is characterized in that a welding margin for welding the reinforcing reinforcing bar is provided.

According to the above configuration, by providing a welding margin, the joint surface between the weir plate and the reinforcing bar can be enlarged, and appropriate welding conditions can be prepared, so that the weir plate and the reinforcing bar can be provided. Can be welded well. As a result, the joint strength between the dam and the reinforcing bar can be ensured.

Preferably, the strut portion has a bent shape in which the cross-sectional shape protrudes to either one of the front and back sides, and the reinforcing reinforcing bar is fixed to the welding margin from the other side by welding.
According to the above configuration, the reinforcing reinforcing bar is arranged on the side opposite to the side on which the bent column portion is projected to increase the rigidity and is welded to the welding margin. Placement is not hindered.

Preferably, the welding margin is formed by thickening the striations forming the mesh of the mesh portion.
According to the above configuration, the configuration of the welding margin is simplified to facilitate manufacturing. Since the amount of steel used for manufacturing is not much different from the amount of steel for a weir without a welding margin, the manufacturing cost can be suppressed. It also makes it difficult for the dam to be deformed.

Preferably, the welding margin is inclined with respect to the axial direction of the reinforcing reinforcing bar at a predetermined welding position.
According to the above configuration, even if the stretching direction of the dam and the axial direction of the reinforcing bar are parallel, the joint strength between the dam and the reinforcing bar can be increased against the force in the stretching direction of the dam. can.

Preferably, the two welding margins adjacent to each other via the strut portion have different inclinations from each other.
According to the above configuration, the anisotropy of the joint strength between the dam and the reinforcing reinforcing bar can be reduced, and the joint strength can be improved.

Another aspect of the present invention is a weir panel for a concrete formwork, in which reinforcing reinforcing bars are welded to the welding margin of the weir.
According to the above configuration, a weir panel for a concrete formwork in which the weir and the reinforcing bar are well welded and their joint strength is ensured is provided.

According to the present invention, the dam and the reinforcing bar can be welded satisfactorily, and the joint strength between the dam and the reinforcing bar can be ensured.

It is a figure which shows the dam which concerns on one Embodiment of this invention, (A) is a plan view, (B) is a front view. It is a figure which shows the same dam and the reinforcing bar arranged at a predetermined welding position, (A) is the enlarged front view of the main part, (B) is the enlarged bottom view of the main part. It is a schematic perspective view which shows an example of the concrete formwork formed by using the same dam.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
The weir panel 1 constitutes a side surface portion of a concrete formwork 2 (see FIG. 3) for constructing a concrete structure, and has a weir plate 10 and a reinforcing reinforcing bar 20.

The weir plate 10 shown in FIG. 1 is a steel lath having a mesh portion 12 between adjacent ribs 11 and 11A (post portions) and the ribs 11 and 11A. In the production of the weir 10, the steel plate (not shown) of the raw material is cut to form the mesh portion 12, and in the secondary processing, the ribs 11 and 11A are formed, and the steel plate is stretched to form the mesh portion 12. It is done by forming.

The ribs 11 and 11A extend in the vertical direction in FIG. 1B, and are arranged alternately at predetermined intervals to form parallel portions. The cross-sectional shapes of the ribs 11 and 11A are substantially V-shaped, and when the concrete formwork 2 is configured, the ribs 11 and 11A are bent so that the top portion 13 protrudes inside (back side) of the weir plate 10. As a result, the rigidity of the ribs 11 and 11A as columns is increased.

A plurality of meshes 15 formed by vertical and horizontal striations 14 are arranged in the mesh portion 12 between the ribs 11 and 11A. In the present embodiment, the mesh 15 is arranged in four rows in one mesh portion 12. As shown in FIG. 1 (B), each mesh 15 is inclined in the front view.

The mesh portion 12 is provided with a welding margin 16. The welding margin 16 is for welding the reinforcing reinforcing bar 20 to the dam 10, and among the striations 14 extending in the same direction as the ribs 11 and 11A (vertical direction in FIG. 1B), the rib 11 is used. , 11A is formed by making the central striation 14 thicker than the other striations 14.

As shown in FIG. 2, the reinforcing bars 20 are arranged on the welding margin 16 from the side opposite to the tops 13 of the ribs 11 and 11A, that is, from the outside (front side) of the dam 10 when the concrete formwork 2 is configured. Will be done. At this time, the reinforcing bar 20 has its axial direction orthogonal to the extending direction of the ribs 11 and 11A.

As shown in FIGS. 1B and 2A, the direction of inclination of each mesh 15 in the front view changes with the ribs 11 and 11A as boundaries. In other words, the mesh 15 of the mesh portions 12 on both sides of the rib 11 is inclined upward with respect to the rib 11, and the mesh 15 of the mesh portions 12 on both sides of the rib 11A is inclined downward with the rib 11A as the center. ing. The direction of inclination of the mesh 15 is an example, and is not limited to these.
The inclination of the striations 14 in the plan view of FIG. 1 (A) and the bottom view of FIG. 2 (B) is symmetrical with respect to the ribs 11 and 11A.

As shown in FIG. 2 (A), when the reinforcing bar 20 is arranged at a predetermined welding position, as shown in FIG. 2 (B), the welding margin 16 facing the reinforcing bar 20 is the reinforcing bar 20. It is inclined with the axis direction of. Further, the welding margins 16 and 16 adjacent to each other via the rib 11 (or the rib 11A) have different inclinations and face the reinforcing reinforcing bar 20.

At the intersection C of the welding margin 16 and the reinforcing bar 20 shown in FIG. 2A, the dam 10 and the reinforcing bar 20 are welded. As a result, the weir panel 1 in which the reinforcing reinforcing bars 20 are fixed to the weir 10 is formed. It should be noted that the dam panel 1 of various sizes can be prepared according to the concrete forming space S (see FIG. 3).

Next, the formation of the concrete formwork 2 using the dam panel 1 having the above configuration will be described.
As shown in FIG. 3, a plurality of dam panels 1 are arranged vertically with the ribs 11 and 11A in the length direction, the tops 13 of the ribs 11 and 11A are on the inside, and the reinforcing bars 20 are on the outside in the horizontal direction. The side edges of the weir panel 1 are tied together with a wire W to form a unit 1U of the weir panel 1. The two units 1U and 1U are stretched so as to surround the concrete forming space S so as to face each other with a predetermined distance. A separator 30 is bridged between the facing dams 10 and 10, and the tip of the separator 30 is locked to the reinforcing reinforcing bar 20. As a result, the concrete formwork 2 surrounding the concrete forming space S is formed.

According to the weir plate 10 of the present embodiment, by providing the welding margin 16 in the mesh portion 12, the joint surface between the weir plate 10 and the reinforcing reinforcing bar 20 can be enlarged, the welding conditions are improved, and the weir. Good welding of the plate 10 and the reinforcing bar 20 is possible. As a result, the joint strength between the weir plate 10 and the reinforcing reinforcing bar 20 is ensured, and the weir plate panel 1 for a concrete formwork of stable quality is provided.

Since the reinforcing reinforcing bars 20 to be welded to the weir plate 10 are arranged on the outside (front side) opposite to the inside (back side) where the tops 13 of the ribs 11 and 11A are located in the weir plate 10, the ribs 11 and 11A are arranged. The top portion 13 does not interfere with the arrangement of the reinforcing reinforcing bars 20.

The welding margin 16 is formed by thickening the striations 14 forming the mesh 15 of the mesh portion 12, and the structure of the welding margin 16 is simple. In order to form the welding margin 16, when making a cut to be a mesh 15 on the steel plate of the raw material of the weir plate 10, it is only necessary to slightly widen the width between the cuts, which is easy to manufacture and is suitable for manufacturing. Since the amount of steel used is not much different from the amount of steel in a weir without a welding margin, the manufacturing cost can be suppressed. Further, the thickening of the striations 14 makes it difficult for the dam to be deformed.

Since the welding margin 16 facing the reinforcing reinforcing bar 20 at the welding position is inclined with the axial direction of the reinforcing reinforcing bar 20, the stretching direction of the dam 10 and the axial direction of the reinforcing reinforcing bar 20 are not parallel to each other. Even so, the welding strength with respect to the force in the tensioning direction of the dam 10 can be increased.

Since the two welding margins 16 and 16 adjacent to each other via the rib 11 (or the rib 11A) have different inclinations from each other, the anisotropy of the joint strength between the dam 10 and the reinforcing bar 20, that is, in a certain direction. Since the property that the strength is strong and the strength in a certain direction is weak becomes small, the bonding strength can be improved.

The present invention is not limited to the above embodiment, and can be appropriately modified without departing from the gist thereof.
In the above embodiment, the striation 14 in the center between the ribs 11 and 11A is set as the welding margin 16, but the striation 14 located at a position deviated from the center may be set as the welding margin 16.
The direction of the weir plate 10 to be stretched may be horizontal in the length direction of the ribs 11 and 11A.
In the above embodiment, in order to form the concrete formwork 2, the ribs of the dam 10 are opposed to each other with the surface on the top 13 side facing inward, but the opposite surfaces may be opposed to each other.
In the above embodiment, the mesh 15 of the mesh portion 12 is formed in four rows, but it may be less than four rows or more than four rows. Further, it is not necessary to incline the mesh 15.
In the above embodiment, the welding margin 16 facing the reinforcing bar 20 at the welding position is inclined with respect to the axial direction of the reinforcing bar 20, but may be formed in parallel.
As the steel lath used for the weir 10, a metal lath may be used, or a wire lath in which a wire is woven into a wire mesh, a punching metal, a hexagonal wire mesh, a crimp wire mesh, a welded wire mesh, or the like may be used.

The present invention can be applied to a weir for a concrete formwork and a weir panel using the same.

1 Weir plate panel 1U Weir plate panel unit 2 Concrete formwork 10 Weir plate 11, 11A Rib (support part)
12 Mesh 13 Rib top 14 Striations 15 Striation 16 Welding margin 20 Reinforcing bars 30 Separator C Crossing W Wire S Concrete forming space

Claims (6)

With multiple columns arranged at regular intervals,
It is provided with a mesh portion provided between the support columns and in which a plurality of meshes are arranged.
A weir for a concrete formwork, characterized in that a welding margin for welding reinforcing reinforcing bars is provided in the mesh portion. The strut portion has a bent shape in which the cross-sectional shape protrudes to either the front or the back side.
The weir for a concrete formwork according to claim 1, wherein a reinforcing bar is fixed to the welding margin by welding from the other side. The concrete formwork weir according to claim 1 or 2, wherein the welding margin is formed by thickening the striations forming the mesh of the mesh portion. The concrete formwork weir according to any one of claims 1 to 3, wherein the welding margin is inclined with respect to the axial direction of the reinforcing bar at a predetermined welding position. The concrete formwork weir according to any one of claims 1 to 4, wherein the two welding margins adjacent to each other via the support column have different inclinations from each other. A weir panel for a concrete formwork in which reinforcing reinforcing bars are welded to the welding margin of the weir according to any one of claims 1 to 5.

Images