JPH10331303A - Precast concrete form and structure with it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight via thinning by lining one face of a flat plate- like precast concrete board with a corrugated steel sheet, and lining the inner face of a concrete form having a hollow cross section with a corrugated steel sheet. SOLUTION: One face of a precast concrete board 11 is lined with a corrugated steel sheet 12 welded with a wire netting 13, and the corrugated steel sheet 12 is integrated with the precast concrete board 11 to mold a form 10. Separator fitting recesses 14 are provided on the side face portion of the form 10, and the corrugated steel sheet 12 is formed into a shape continued with recesses and projections in turn as the reinforcing member of the precast concrete board 11. The corrugated steel sheet 12 and precast concrete board 11 have the same planar size, and the whole one face of the precast concrete board 11 is lined with the corrugated steel sheet 12. This structure is made lightweight, and its transportation and installation can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an RC structure and an SRC
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete formwork used as a disposal formwork of a general conventional concrete placing method in a structure, and a structure such as a wall, a column, and a beam constructed using the formwork.

[0002]

2. Description of the Related Art In recent years, at construction sites, attempts to use a thin precast concrete form as an alternative to a plywood form have been vigorously conducted due to a shortage of form work and conservation of a tropical forest. Have been done.

For example, as a precast concrete form used as a wall form, as shown in FIG. 15, a precast concrete slab 151 is provided with a shear line 152 on a post-cast (cast in place) concrete side surface. It has been known. The precast concrete formwork is intended to be integrated with the post-cast concrete by the shear line 152.

As a precast concrete formwork used as a formwork for columns or beams, there is known a form having an uneven shear cotter inside a mold having a hollow section or a U-shaped section. Such a precast concrete form is intended to be integrated with post-cast concrete by a shear coater.

[0005] These precast concrete forms are used as discarded forms, and there is an advantage that the work of dismantling and replacing the forms is not required and the construction period can be shortened. Also,
For example, by using a precast concrete form in which a finishing material such as a tile is previously driven as the outer form of the outer wall, an external finishing step is not required, and the construction period can be significantly reduced.

[0006]

The precast concrete form into which the above-described shear line is driven is relatively thick (about 80 mm), and a part of the thickness of the precast concrete form (usually, the thickness of the precast concrete form). (-30 mm) can be treated as a structural cross section, but it is heavy, so it is not easy to transport and install, and the workability at the site is poor.

[0007] Further, since the shear bar is manufactured by welding a plurality of reinforcing bars that are bent in a complicated manner and assembling them into a truss shape, the number of processing steps is extremely large, and there is a limit to the merit in cost due to mass production.

[0008] An object of the present invention is to provide a novel precast concrete formwork that can be reduced in weight and cost by thinning, and can further improve workability on site.

It is a further object of the present invention to provide a precast concrete formwork which is thin but can form part of a structural cross section.

[0010]

In order to reduce the thickness and weight of a precast concrete formwork, the present inventor provides a simple method of reinforcing precast concrete, secures integrity with post-cast concrete, and furthermore, works on site. As a result of intensive studies on the properties, the present invention has been achieved.

That is, the first aspect of the present invention relates to a precast concrete formwork characterized in that a corrugated steel plate is lined on one side of a flat precast concrete plate.

A second aspect of the present invention relates to a precast concrete formwork characterized in that a corrugated steel sheet is lined on the inner surface of a precast concrete mold having a hollow cross section.

[0013] A third aspect of the present invention relates to a precast concrete formwork characterized in that a corrugated steel sheet is lined on the inner surface of a precast concrete mold having a U-shaped cross section.

A fourth aspect of the present invention is a structure constructed using the precast concrete formwork of the present invention as a disposal form, wherein the corrugated steel sheet is sandwiched between precast concrete and post-cast concrete. The present invention relates to a structure characterized by having a structure as described above.

In the present invention, a corrugated steel sheet (hereinafter, referred to as a steel sheet) is used.
It is called "corrugated steel sheet". The backing material, which has a simple structure based on), is formed integrally with the precast concrete,
By increasing the rigidity of precast concrete,
This achieves a thinner and lighter precast concrete formwork than before. Further, the backing material made of such a corrugated steel sheet has the same function as a conventional shear cotter, and can ensure the integrity of the precast concrete formwork and the post-cast concrete. Furthermore, since it has a steel backing material, it is possible to weld a structural reinforcing bar or the like to it in advance, and it is also possible to save the labor for arranging reinforcing bars on site.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings, but it is needless to say that the present invention is not limited to these embodiments.

FIGS. 1 and 2 show an example of the first flat precast concrete form of the present invention, which is mainly used as a discard form of a wall. FIG. 1 is an overall view and a cross-sectional view of a formwork 10, and FIG. 2 is a perspective view of only a steel material.

The formwork 10 is formed by backing a corrugated steel plate 12 having a wire mesh 13 welded to one surface of a precast concrete plate 11. The corrugated steel plate 12 is integrated with the precast concrete plate 11. Further, a concave portion 14 for attaching a separator is provided on the side surface portion.

The corrugated steel sheet 12 is mainly thin (30 mm).
) Of the precast concrete slab 11), and has a shape in which concave portions and convex portions are alternately continuous. The shape of the concave and convex portions is not limited to the rectangular shape as shown in FIG. 2, but may be any shape. For example, in addition to a triangular wave and a triangle, as shown in FIG. It can be trapezoidal or the like. In addition, concave
The depth, height and pitch of the projections need to be such that the integration with the precast concrete slab 11 and the post-cast concrete is sufficiently ensured. Usually, the depth and height of the depressions and projections are About 5mm to 15mm, preferably 8m
m to 15 mm, and the pitch is 100 mm to 250
mm.

It is preferable that the concave portions and convex portions of the corrugated steel sheet 12 are alternately continuous in the horizontal direction when the mold 10 is erected as a discarded mold of a wall. That is, the corrugated steel sheet 12
Since the bending rigidity in the direction in which the concave portions and the convex portions are alternately continuous is small, and in particular, the mold of the present invention is formed thinner than the conventional one, even if the wire mesh 13 or the like is reinforced by welding. If the concave and convex portions of the corrugated steel plate 12 are erected alternately in the vertical direction, the entire form may be easily bent or broken, and the work of installing the form may be difficult.

In the example shown in FIG. 1, the left and right end portions of the corrugated steel plate 12 are embedded in the precast concrete slab 11, for example, as shown in the sectional view of FIG.
BB 'cross-sectional view of FIG. 2), the corrugated steel plate 12 and the precast concrete slab 11 may have the same size in plan view, and the corrugated steel plate 12 may be lined on one entire surface of the precast concrete slab 11. Note that, even in the case of the embodiment shown in FIG. 1, it is preferable to use the corrugated steel plate 12 having the same size as the precast concrete slab 11 in plan as much as possible.

The corrugated steel sheet 12 is also used as a part of a forming die for forming a precast concrete formwork. That is, as a method for manufacturing the above-mentioned flat precast concrete formwork, a flat casting method in which concrete is poured into a molding die (mold) and the upper surface thereof is leveled is generally used. By pressing the upper surface of the concrete with the steel plate 12, the precast concrete slab 11 can be formed with a desired thickness at the same time as the integration.

The wire mesh 13 (see FIGS. 1 and 2) is mainly for reinforcing the corrugated steel sheet 12 and increasing the rigidity of the thin precast concrete slab 11.

The specifications of the corrugated steel sheet 12 and the wire mesh 13 can be appropriately designed according to the size of the precast concrete formwork and the specifications of each other. Specifically, for example, the corrugated steel sheet 12 has a thickness of about 0.6 mm to 1.2 mm, and the wire mesh 13 has a steel wire having a diameter of 2.0 mm to 4.0 mm in a grid shape of 50 mm to 150 mm. The assembled one is suitably used.

Corrugated steel sheet 1 using wire mesh 13 as described above
The second reinforcing method is relatively easy to process and has a great merit in terms of cost. However, on the other hand, since the wire mesh 13 is overlapped and welded to the surface of the corrugated steel plate 12, in order to suppress the thickness of the entire formwork, the depth and height of the concave and convex portions of the corrugated steel plate 12 are sacrificed. In order to ensure sufficient integration with the precast concrete slab 11 and the post-cast concrete, it may be necessary to devise measures such as reducing the pitch between the concave portions and the convex portions.

In the present invention, the wire mesh 13 as described above is used.
Corrugated steel plate 12 instead of corrugated steel plate 12
It can also have high rigidity itself. One example will be described with reference to FIGS.

The corrugated steel plate 12 'shown in FIG. 5 is obtained by welding a plurality of reinforcing plates 51 into recesses on both front and back surfaces of the corrugated steel plate 12 as shown in FIG. Further, the corrugated steel sheet 1 shown in FIG.
2 ”is obtained by welding a plurality of reinforcing plates 51 into a concave portion on one side of the corrugated steel sheet 12 as shown in FIG.

As described above, by attaching the reinforcing plate 51 to the inside of the concave portion of the corrugated steel sheet, the depth and height of the concave portion and the convex portion of the corrugated steel sheet 12 as in the reinforcing method using the wire mesh 13 described above. It is possible to reduce the thickness of the entire formwork without sacrificing the thickness, and it is also possible to sufficiently secure the integrity with the precast concrete slab 11 and the post-cast concrete without reducing the pitch of the concave and convex portions. become.

Further, in the formwork of the present invention, a perforated steel sheet can be used as the corrugated steel sheet. In this case, for example, it is preferable to form the mold in a state where a cavity is provided inside the convex portion 15 of the corrugated steel sheet 12 in FIG. That is,
The post-cast concrete is filled in the cavity, and high integrity between the formwork of the present invention and the post-cast concrete can be ensured.

As described above, in the present invention,
A backing material based on a corrugated steel plate 12 is formed integrally with the precast concrete slab 11 to increase the rigidity of the precast concrete, thereby reducing the stiffness of the precast concrete to about half (for example, 30 mm) the conventional one using a shear bar as shown in FIG. To 40 mm). Also,
The corrugated steel plate 12 has the same action as a conventional shear cotter, and can also ensure high integrity between precast concrete and post-cast concrete. Furthermore, since the backing material has a simple configuration based on a corrugated steel sheet and is easy to process, and since such a corrugated steel sheet can be effectively used at the time of forming a mold, there is a great merit in manufacturing cost.

Next, another example of the first flat precast concrete formwork of the present invention will be described with reference to FIGS. 7 and 8. FIG. FIG. 7 is an overall view and a sectional view of the mold 70,
FIG. 8 is a perspective view of only a steel material. The corrugated steel sheet 12 may have any shape as described above.
The reinforcing method and the like can be performed in the same manner as described above.

The formwork 70 is obtained by welding structural steel bars 71a and 71b to the surface of the formwork 10 shown in FIG. 1 opposite to the precast concrete surface of the corrugated steel plate 12. That is, since the corrugated steel plate 12 made of steel is lined with the formwork of the present invention, it is possible to weld the reinforcing bars 71a and 71b to the corrugated steel plate 12 in advance at the factory, and to distribute the steel bars on site. Muscle work can be saved. The reinforcing bar 71
If it is difficult to carry the formwork to the site in the state where a and 71b are welded, welding can also be performed at the site.

The reinforcing bars 71a and 71b as described above are, as will be described later in detail, formed by adjacent formwork,
Furthermore, for connection and fixation with columns, beams, floor slabs, etc., FIG.
And it is preferable to make it protrude to one side of a formwork as shown in FIG. The length of this overhang is usually
It is 30 times or more the rebar diameter. It is also preferable to provide a hook at the tip of the overhang portion.

As described above, when the structural reinforcing steel is welded to the surface of the corrugated steel sheet 12 opposite to the precast concrete surface side, the integrity of the precast concrete and the post-cast concrete can be sufficiently improved. Thus, sufficient rigidity and proof stress can be secured. For this reason, there is a high possibility that a part or all of the precast concrete formwork can be treated as a structural cross section by sufficiently performing the joint between the forms.

FIG. 9 shows an example of a precast concrete formwork having a second hollow section according to the present invention. In this formwork 90, a precast concrete mold 91
Corrugated steel sheet 1 with the same wire mesh 13 as above welded to the inner surface of
2 is backed. The precast concrete formwork 90 is used as a discard formwork of a pillar, and has a hollow cross section corresponding to the sectional shape of the pillar. Note that FIG.
Is provided with an opening at a portion where it is connected to a wall panel (indicated by a dashed line in the figure), and concrete is cast integrally with the pillar and the wall. Further, in the case of a form of an independent pillar having no connection with a wall, the above-mentioned opening is not provided, and a complete hollow section is formed.

FIG. 10 shows an example of a precast concrete formwork having a U-shaped cross section according to the third aspect of the present invention. In this formwork 100, a corrugated steel plate 12 to which a wire mesh 13 similar to the above is welded is lined on the inner surface of a precast concrete mold 101. The precast concrete formwork 100 is used as a discard formwork of a beam, and has a U-shaped cross section corresponding to the cross-sectional shape of the beam.

In the precast concrete formwork having a hollow section or a U-shaped section as described above, similarly to the above-mentioned plate-shaped precast concrete formwork, the reinforcing bar of the column portion or the beam portion is previously formed on the corrugated steel plate 12. It can be welded and there is a high possibility that part or all of the precast concrete formwork can be treated as a structural section.

In forming a precast concrete form having a hollow cross section or a U-shaped cross section, the corrugated steel sheet 12 can be used as a part of a forming die.
Simultaneously with these integration, a precast concrete mold can be formed with a desired thickness.

Next, an example of construction of a load-bearing wall using a precast concrete formwork 70 as shown in FIG. 7 is shown in FIG.
This will be described with reference to FIGS. 11 is an elevational view showing the installation state of the formwork, FIG. 12 is a cross-sectional view along the AA ′ plane in FIG. 11, FIG. 13 is a cross-sectional view along the BB ′ plane in FIG. FIG. 12 is a sectional view taken along the line CC ′ in FIG. 11.

First, in order to increase the accuracy of the form spacing at the time of setting up the form, width fixing members (not shown) are fixed to the floor at a predetermined pitch.

Next, the mold 70 is set up with the corrugated steel plate 12 facing inward. At this time, connection and fixation of the adjacent wall formwork, furthermore, columns, beams, and floor slabs are performed by the reinforcing bars protruding from the formwork. In addition, it is particularly preferable to reinforce the lower part of the formwork by welding or the like against the concrete placing pressure. In order to reduce the unevenness at the joint between the formwork, the joint surface between the formwork is as shown in FIG. Irregularities 11
It is preferable to add 1. Then, as shown in FIG. 14, a separator 112 for keeping the interval of the molds constant is passed through the concave portion 14 (see FIG. 7) provided on the joining surface of the molds and the channel material 113 and attached.

Next, for example, the floor form 11
4 (see FIG. 12), and after assembling predetermined reinforcing bars, concrete is poured. At this time, it is preferable to divide concrete into two or three times in order to prevent deformation of the wall form and spillage.

Finally, after the temporary material such as the channel material 113 is removed, joint processing of the form joint and the separator is performed. At this time, by attaching the separator 112 to the mold joint as in the above-described example, joint processing of the mold joint and the separator can be simultaneously and efficiently performed.

When a column is to be constructed using a formwork 90 as shown in FIG.
0 can be suspended from above and installed. At this time, since the mold of the present invention is thinner and lighter than the conventional mold, the working efficiency is high. When a beam is constructed using the formwork 100 as shown in FIG.
After installing 0, the reinforcement can be assembled.

In the structures such as walls, columns and beams constructed as described above, a steel plate is sandwiched between the precast concrete and the post-cast concrete, and an improvement in overall sound insulation performance is expected.

[0046]

As described above, the precast concrete form of the present invention has the following effects. (1) It can be manufactured with a thickness of about half that of the conventional precast concrete formwork, and as the weight is reduced, the transportation and installation are facilitated, and the workability on site is improved. (2) Since the backing material has a simple configuration based on a corrugated steel sheet, the number of processing steps can be reduced, and the corrugated steel sheet can be effectively used at the time of forming the form, so that the cost can be reduced. (3) The corrugated steel sheet has the same action as a conventional shear cotter, and can improve the integration with the post-cast concrete. (4) In particular, when a structural reinforcing bar is welded to the surface of the corrugated steel sheet opposite to the precast concrete surface side, it is possible to save labor in the on-site reinforcing work and to integrate the precast concrete and the post-cast concrete. Performance can be extremely high and sufficient rigidity and proof stress can be secured.
It is possible that part or all of the precast concrete formwork can be treated as a structural section. (5) Since it is used as a discarded formwork, it is not necessary to disassemble and rearrange the formwork, thereby shortening the construction period.

Further, in a structure such as a wall, a column or a beam constructed using the precast concrete formwork of the present invention, a corrugated steel sheet is sandwiched between the precast concrete and the post-cast concrete. Thus, a structure having high sound insulation performance is realized.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a flat precast concrete formwork of the present invention.

FIG. 2 is a perspective view showing only a steel material in the mold of FIG. 1;

FIG. 3 is a perspective view showing an example of a corrugated steel sheet used for the formwork of the present invention.

FIG. 4 is a cross-sectional view showing another example of the flat precast concrete formwork of the present invention.

FIG. 5 is a perspective view showing another example of a corrugated steel sheet used for the formwork of the present invention.

FIG. 6 is a perspective view showing another example of a corrugated steel sheet used for the formwork of the present invention.

FIG. 7 is a view showing an example of a flat precast concrete formwork of the present invention in which a structural reinforcing bar is welded.

FIG. 8 is a perspective view showing only a steel material in the mold of FIG. 7;

FIG. 9 is a sectional view showing an example of a precast concrete formwork having a hollow section according to the present invention.

FIG. 10 is a sectional view showing an example of a precast concrete formwork having a U-shaped section according to the present invention.

FIG. 11 is an elevational view showing a state where the flat precast concrete formwork of the present invention is set up as a wall formwork.

12 is a cross-sectional view taken along the line AA ′ in FIG.

13 is a cross-sectional view taken along the plane BB ′ in FIG.

14 is a cross-sectional view taken along the plane CC ′ in FIG.

FIG. 15 is a view for explaining a conventional precast concrete formwork.

[Explanation of symbols]

10, 70, 90, 100 Precast concrete formwork 11 Precast concrete plate 12, 12 ', 12 "steel plate 13 Wire mesh 14 Depressed portion for mounting separator 51 Reinforcement plates 71a, 71b Reinforcing bar 91, 101 Precast concrete mold 111 Unevenness 112 Separator 113 Channel Material 114 Floor form 151 Precast concrete slab 152 Shear bar

Claims (8)

[Claims] 1. A precast concrete formwork, wherein a corrugated steel plate is lined on one side of a flat precast concrete slab. 2. A precast concrete formwork, wherein a corrugated steel plate is lined on the inner surface of the precast concrete mold having a hollow cross section. 3. A precast concrete formwork, wherein a corrugated steel sheet is lined on the inner surface of a precast concrete mold having a U-shaped cross section. 4. The precast concrete formwork according to claim 1, wherein a structural reinforcing bar is welded to a surface of the corrugated steel sheet opposite to a side of the precast concrete surface. . 5. The precast concrete formwork according to claim 1, wherein a wire mesh is welded to the precast concrete surface side of the corrugated steel sheet. 6. The precast concrete formwork according to claim 1, wherein the corrugated steel sheet has a reinforcing material in a concave portion on one or both sides. 7. A structure constructed using the precast concrete formwork according to any one of claims 1 to 5 as a disposal form, wherein the corrugated steel sheet is placed between precast concrete and post-cast concrete. A structure having a sandwiched structure. 8. The structure according to claim 7, wherein a structural rebar is welded to the corrugated steel sheet.