JPH0730625B2 - How to build a waffle slab - Google Patents

Description

TECHNICAL FIELD The present invention relates to a waffle slab construction method. More specifically, the present invention relates to the improvement of a trapezoidal mold when constructing a waffle slab.

(B) Conventional technology A waffle slab is a slab that has a number of regular concave patterns arranged at the bottom of the ceiling slab and looks like a rhombus or a beehive when viewed from below. , Used in the halls of public halls and ceilings of gymnasiums, for example. However, the horizontal cross-sectional shape of one recess is not limited to a quadrangle or a hexagon, but may be a circle or the like.

Conventionally, as a method for constructing such a waffle slab, a lightweight trapezoidal mold (a trapezoid for constructing a waffle slab) made of a hard synthetic resin foam (such as expanded polystyrene) is mounted on a flat plate frame of a veneer plate supported by columns. A large number of molds are regularly placed, concrete is placed on it, and after the concrete has hardened, the flat form is removed, and then each trapezoidal mold is removed from the concrete layer downward. Has been done.

(C) Problems to be Solved by the Invention However, concrete exhibits a strong shrinkage phenomenon when hardened, and the synthetic resin trapezoidal mold and the cement have some adhesiveness. Therefore, it is difficult to easily remove the trapezoidal mold from the concrete layer after the hardening of the concrete, and it is difficult to remove the trapezoidal mold easily. Especially, the waffle slab construction site using many trapezoidal molds. There was a big hindrance to workability. When a larger trapezoidal mold is used, it may be impossible to remove the mold.

For this reason, it has been proposed to coat the molding surface of the trapezoidal mold with a plastic film for improving the mold releasability to construct a waffle slab, but this is not sufficient for easy demolding. there were.

In this regard, the present inventors previously described the trapezoidal mold as follows.
We have found a waffle slab construction method that can easily remove the trapezoidal mold after concrete hardening by using the divisible trapezoidal mold in which the central block and a plurality of peripheral blocks surrounding the side circumference are assembled.

However, when such a separable trapezoidal mold is used, demolding can be performed very easily, but there is a gap between the blocks that make up the trapezoidal mold, and concrete enters and the molded concrete is formed. There has been a problem that linear projections are formed on the surface.

For this reason, it is conceivable to install joint material with a wedge-shaped cross section that seals the gaps between the blocks, but in this case as well, the trace of the joint material is generated on the concrete molding surface, and it is smooth and beautiful. It is difficult to obtain a concrete molding surface, and the jointing of the joint material itself is complicated, resulting in a problem in workability.

The present invention has been made in view of such circumstances, and a waffle capable of easily removing (demolding) a trapezoidal mold from a concrete layer after hardening of concrete and obtaining a smooth and beautiful concrete molding surface. It is intended to provide a slab construction method.

(D) Means for Solving the Problems Thus, according to the present invention, concrete is poured from above with a large number of trapezoidal dies placed at a predetermined interval on a flat plate form, and after the concrete is hardened, the flat plate is removed from the concrete layer. It consists of a method of constructing a waffle slab by removing the formwork and then the trapezoidal mold, and as the trapezoidal mold, a divisible rectangular trapezoidal mold in which a central block and a plurality of peripheral blocks surrounding its side circumference are gathered. While using this trapezoidal mold, the entire molding surface of the trapezoidal mold is covered with a plurality of non-foamed resin sheet molded articles that can be collectively collected on a line different from the assembly line of each block, There is provided a waffle slab construction method characterized by performing casting.

The first feature of the present invention is that a rectangular trapezoidal mold which has been conventionally integrally formed of a synthetic resin foam or the like and used is divided and has a specific divided structure. The divided structure is composed of a central block and peripheral blocks. Here, the central block is used by being surrounded by a plurality of peripheral blocks so that its side periphery does not come into contact with concrete at the time of assembly, and constitutes the central portion of the trapezoidal mold. On the other hand, the peripheral block is composed of a plurality of blocks.

The shape of each block is not particularly limited as long as a rectangular trapezoidal body can be obtained when assembled. However, normally, as shown in FIG. 1, a central block 11 is combined with eight peripheral blocks consisting of a corner block 12 and a side block 13, and a set of these nine blocks is used to show in FIG. It is suitable to construct a trapezoidal truncated pyramid shape. However, as shown in FIG. 3, a rectangular parallelepiped trapezoidal mold may be formed by a set of nine blocks including a rectangular center block 14 and a peripheral block 15. Also, as shown in FIG. 4, the shape of each block itself is formed into a truncated quadrangular pyramid, and this is used as the center block
Alternatively, nine peripheral blocks 17 may be assembled and configured.

The center block and the peripheral block are each preferably made of a rigid synthetic resin foam in terms of strength, weight, etc. Specifically, specifically, a polystyrene foam, a rigid polyvinyl chloride foam, a rigid polyurethane. Examples thereof include foams, and polystyrene foams are preferable. However, the molding surface may be appropriately subjected to a mold release treatment. In addition, the inside of each block may be hollow, and in that case, a reinforcing structure such as a rib may be appropriately provided in the hollow portion.

A second feature of the present invention is that, when the aggregate block is used as one trapezoidal mold for concrete pouring, a plurality of specific resin sheet molded products are aggregated and covered on the molding surface of the trapezoidal mold. And This resin sheet molded product is
Generally, it is composed of polystyrene-based, polyolefin-based, or vinyl chloride-based non-foamed sheet, and its thickness is 0.4
It is preferably about 2 mm. If it is less than 0.4 mm, it easily breaks, and if it exceeds 2 mm, it becomes heavy and it is not preferable in terms of workability. Specific examples of such resin sheets include impact resistant polystyrene sheets, AS resin sheets, ABS resin sheets, polyethylene sheets, polypropylene sheets, vinyl chloride sheets and the like. From the viewpoint of surface finish, especially the smoothness of the surface of the molded concrete, it is preferable to use a polystyrene resin sheet molded product.

The shape of the resin sheet molded product is a four-divided shape that can collectively cover the molding surfaces of the trapezoidal mold, and when covered, the assembly line can be set at a position different from the assembly line of the block. Shaped. For example, first to fourth
When a trapezoidal die in which nine blocks are assembled as shown in the figure is used, it is suitable to have a four-divided shape in which a cross-shaped assembly line passing through the center points of the trapezoidal die is set at the time of assembly. . An example of such a resin sheet molded product (cover piece 18) is shown in FIG.
As shown in the figure. In the figure, 18A to 18D represent resin sheet molded products before assembly, respectively, in FIG. 5, X and Y represent assembly lines of the sheet molded products, and broken lines represent assembly of blocks forming a trapezoidal mold. It shows a line.

When using a sheet-formed product in which a trapezoidal die as shown in FIG. 5 is assembled in a butt shape at a cross-shaped assembly line passing through the center point, it is preferable to use the same shape as each resin sheet molded product. This is preferable in that the molding facility and the manufacturing process of the molded product can be simplified because it is possible. However, when they are collectively covered, the resin sheet molded products may be formed in such a size that the edge portions of the resin sheet molded articles may partially or partially overlap each other.

Further, when the above resin sheet molded products are assembled, if each molded product is adhered and joined along the assembly line with an adhesive tape or the like, concrete invades into a slight gap between the molded products in the assembly line, and as a result, it is fine. Unevenness and line projections can be prevented, which is more preferable.

(E) Action Among the blocks that make up the trapezoidal mold, the central block has only one surface (upper surface) that serves as the molding surface, so that it is easily separated from the concrete molding surface by the downward force. After the central block is removed, the center of the trapezoidal mold is opened, so that the workability of manually removing the peripheral block is significantly improved.

Furthermore, because the concrete is cast while the entire molding surface of the trapezoidal mold is covered with the non-foamed resin sheet molded product, unnecessary irregularities and linear projections are substantially formed on the molding surface of the obtained concrete layer. It is possible to construct a beautiful waffle slab with a smooth surface.

The resin sheet to be covered has good releasability from concrete and is composed of a plurality of divided molded products, so that work at the time of covering and detaching work after placing concrete can be performed easily and smoothly. It is also convenient in terms of handling during transportation.

(F) Example As shown in FIG. 7, a hollow quadrangular pyramid-shaped hollow trapezoidal structure having a reinforcing frame 20 and ribs 21 inside (upper side 944 mm, lower side 950 mm,
A height of 320 mm and a bulk specific gravity of 0.025 to 0.033) are produced by in-mold molding of expandable polystyrene beads, one of which is used as the central block 16.
Eight pieces were combined as the peripheral blocks 17 to form one trapezoidal mold (2850 × 2850 × 320 mm). The trapezoidal die in which each of the blocks is assembled corresponds to the trapezoidal die 1C in FIG.

On the other hand, by subjecting a polystyrene sheet to vacuum forming, a large number of cover pieces 18 (upper side 1422 mm, lower side 1425 mm, height 320 mm, thickness 1.5 mm) having a square upper surface as shown in FIG. 6 were produced.

First, as shown in FIG. 9, a plurality of support columns 2 support a flat plate form 3 made of veneer plate, and the above-mentioned 9
A trapezoidal mold 1C as shown in FIG. 4 in which individual blocks (center block and peripheral block) were assembled was placed and fixed at predetermined intervals. The surrounding area was fixed with a face board so that the trapezoidal mold 1C would not move due to vibration during the work of arranging or placing concrete. The fixing may be performed by applying a general vinyl acetate resin adhesive to the mounting surface.

Then, each of the trapezoidal molds was covered by covering four of the cover pieces 18, and the assembly lines X and Y were adhered with a transparent adhesive tape 19 as shown in FIG. As a result, the molding surface of the trapezoidal mold was in a state of being covered with the polystyrene sheet.

In this state, reinforcing bars were arranged between the trapezoidal molds, and concrete was poured from above.

After the concrete was hardened, the columns 2 and the plate form 3 were removed. This state is shown in FIG. In the figure, 4 indicates a hardened concrete layer.

Here, the central block 16 forming the trapezoidal mold was detached extremely easily by applying a downward force by hand. Then, the four peripheral blocks forming the side portion were easily detached by pulling toward the detachment space side of the central block. The four peripheral blocks forming the remaining corners were easily detached by pulling in the central direction.

Further, the cover piece 18 attached to the concrete molding surface was easily detached by pulling it outward by hand. The resulting waffle slab molding surface had no irregularities or linear projections due to the gaps between the blocks forming the trapezoidal mold, and the surface was extremely smooth and beautiful.

On the other hand, when polystyrene sheet molded products that cover individual blocks are used, large gaps between the blocks cause large linear protrusions on the molding surface of the waffle slab, and it takes a significant amount of time to remove them. Needed. In addition, a long joint material with a T-shaped cross section was fitted into this gap, and it was placed with concrete using tape, and then concrete was placed. However, a wrinkle slab with a smooth surface can be easily created because the joint material itself remains on the molding surface. Could not be built into.

(G) Effect of the Invention According to the waffle slab construction method of the present invention, the demolding of the trapezoidal mold after concrete hardening can be performed extremely easily and smoothly, and the waffle slab having a smooth surface and beautiful surface can be easily produced. Obtainable. Therefore, it becomes possible to remarkably improve the workability when constructing a large number of waffle slabs or a large size waffle slab.

[Brief description of drawings]

FIG. 1 is a perspective view showing a divided state of a trapezoidal die of an embodiment used in the present invention, FIG. 2 is a perspective view showing the same assembled state, and FIGS. 3 and 4 are other embodiments. FIG. 5 is a perspective view showing an assembled state of the trapezoidal die of the example, FIG. 5 is a perspective view illustrating a cover state of the trapezoidal die by the non-foamed resin sheet molding used in the present invention, and FIG. 6 is the same non-foamed resin. FIG. 7 is a perspective view illustrating a sheet molded product, FIG. 7 is a cross-sectional view showing an example of each block constituting the trapezoidal mold of FIG. 4, and FIG. 8 is a trapezoidal shape of the non-foamed resin sheet molded product in the embodiment. FIG. 9 is a perspective view showing a cover state of the mold, FIG. 9 is an explanatory view showing a mounting state of the trapezoidal mold in the construction method of the present invention, and FIG. 10 is an explanatory view showing a molding state of the trapezoidal mold. 1A, 1B, 1C …… trapezoidal type, 2 …… pillar, 3 …… flat plate form, 4
…… Concrete layer, 11,14,16 …… Center block, 12…
… Corner block, 13 …… side block, 15,17 …… peripheral block, 18,18A, 18B, 18C, 18D …… resin sheet molded product (cover piece), 19 …… adhesive tape, 20 …… reinforcement Frame, 21 ...
… Ribs, X, Y… Assembly line.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Teru Maru Nagai, 2182-18 Kurihashi, Kurihashi-cho, Kitakatsushika-gun, Saitama Prefecture (56) References JP-A-2-43465 (JP, A) , U)

Claims (1)

[Claims] 1. A waffle in which a large number of trapezoidal dies are placed at predetermined intervals on a flat plate formwork, concrete is poured from above, and after the concrete hardens, the flatbed formwork is removed from the concrete layer and then the trapezoidal form is removed. A method of constructing a slab is used. As the trapezoidal mold, a divisible rectangular trapezoidal mold in which a central block and a plurality of peripheral blocks surrounding the side circumference thereof are gathered is used. A waffle slab characterized by pouring concrete in a state where the entire molding surface of the mold is covered with a plurality of non-foamed resin sheet molded products that can be collected on a line different from the above-mentioned block assembly line. How to build.