JPH03271463A - Concrete placing mold form - Google Patents

Abstract

PURPOSE:To form a neat concrete surface by forming a mold form, provided with a hollow interior by a continued-foaming synthetic resin plate, and mounting sash bars at a required interval in one surface outside the mold form. CONSTITUTION:There is formed a mold form A consisting of hollow parts 2a, 2b, 2c formed of a synthetic resin plate 1 of continued-foaming quality having water and gas permeability over its total surface by dividing its interior 2 into a plurality of streaks. Synthetic resin-made sash bars 3 are mounted to the side surface 5 opposite to a concrete placing side surface 4 of the mold form A.

Description

[Detailed Description of the Invention] <Industrial Application Field> This invention can remove most of the moisture generated from concrete during concrete placement in a short time, and simultaneously improve the surface condition and curing condition after hardening. This relates to formwork for concrete pouring.

<Prior Art> As is well known, excessive water is added to concrete poured when constructing a concrete structure in order to ensure workability. This excess water is removed by compacting the concrete after it is placed.

However, the water separated during compaction collects on the formwork surface with air bubbles, which causes so-called avatars on the hardened concrete surface.

This not only impairs the aesthetic appearance of the concrete surface, but also causes cracks due to cross-sectional defects.

In addition, excess water that collects at the interface between the poured concrete and the formwork increases the water-to-cement ratio of the concrete in this area, reducing the durability of concrete after hardening and accelerating deterioration due to salt damage. .

The above-mentioned defects in poured concrete are due to the conventional use of formwork made of wooden plywood (plywood) or steel frames when pouring concrete.

With the aim of eliminating such defects and actively draining the moisture present on the concrete pouring surface to the outside,
In recent years, molds with a water permeable layer on the surface of the formwork (Japanese Patent Laid-Open No. 1983-
No. 11766), a formwork consisting of a weir plate with small holes for dewatering, thick timbers to maintain the shape of this weir plate, and shoring to increase the rigidity of this thick timber (Japanese Patent Laid-Open No. 62 -1
60366), a formwork with a water-permeable and air-permeable peeling material attached to one side of a rigid one/tan form board (Japanese Patent Application Laid-open No. 63-55264), and a water-conducting formwork on the concrete pouring side of the formwork. A formwork in which a buffer sheet and a water-permeable filter sheet are laminated (Japanese Patent Application Laid-open No. 1-310061) has been proposed.

<Problems to be Solved by the Invention> However, although it is possible to remove and eliminate excess moisture generated from concrete during concrete pouring using any of these formworks, it is possible to remove and eliminate excess moisture generated from concrete during concrete pouring, but after the concrete is poured and solidified and the formwork is removed, There were problems such as the curing of concrete requiring a great deal of labor and the appearance of blisters remaining on the concrete surface.

Means for Solving the Problems> This invention was made as a result of studies to solve the above problems, and it can be easily peeled off even when the concrete is completely hardened to maintain its aesthetic appearance, and it can also be used to cure the concrete. We have discovered a formwork made of open-cell synthetic resin plates with water permeability and air permeability that allows curing in a wet state while securing the necessary moisture.

That is, the present invention provides a formwork for concrete pouring, which is made of an open-cell synthetic resin board with water permeability and air permeability, is hollow inside, and is attached to one of the outside surfaces with crosspieces at required intervals. It is something to do.

<Function> The formwork of this invention is made of open-cell synthetic resin board with water permeability and air permeability, and has a hollow structure inside, so moisture in the poured concrete is absorbed into the area where the concrete surface comes in contact. Penetrates into the interior through the open-cell surface of the formwork,
Furthermore, it is discharged from the hollow interior to the outside through the open cell surface on the opposite side.

<Example> An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the formwork according to the present invention. That is,
In the figure, reference numeral 1 denotes a synthetic resin plate, and the entire surface of the resin plate 1 is made of an open-cell material having water permeability and air permeability, and its interior 2 is hollow. In the formwork A made of an open-cell synthetic resin plate having such a structure, the interior 2 is divided into a plurality of hollow sections 2a, 2b, 2c, etc., as shown in the figure, including the purpose of reinforcing the formwork A.・It is composed of. Reference numeral 3 denotes a synthetic resin crosspiece formed on the opposite side 5 of the concrete pouring side 4 of the formwork A.

When concrete is poured using the formwork of the present invention having the above-described structure, water in the concrete is removed by the open-cell structure having water permeability and air permeability on the concrete casting side surface 4 of the formwork A. Since the pouring is carried out at an appropriate speed from the surface through the hollow interior to the open-cell surface on the opposite side 5, breathing water and air bubbles in the concrete are quickly discharged outside the formwork, and as a result, the surface of the concrete is filled with air bubbles. , avatar water and water avatar are reduced to almost nothing, and a dense concrete structure can be formed. Moreover, the strength of the surface concrete develops quickly.
It has a great initial curing effect, and it is possible to create strong, dense, and beautiful concrete and reit structures in a shorter construction period than conventional methods.

In addition to increasing surface strength, it is also highly effective in slowing down the carbonation rate, reducing and suppressing salt permeability, and can also strengthen salt damage resistance.

The formwork of the present invention, which is made of an open-cell synthetic resin board with water permeability and air permeability, and whose interior is hollow, is made of a synthetic resin such as vinyl chloride resin, polyethylene resin, or polypropylene resin, and is treated with a foaming agent. It can be obtained by filling the mixed foamable pellets into a mold capable of producing a mold as shown in FIG. 1, and heating it. The expansion ratio is about 2 to 10 times.

Moreover, the hollow part 2a partitioned into multiple strips in FIG.
The shapes of 2b and 2C are rectangles, but the shapes can be the rhombus in Figure 2(a), the triangle in Figure 2(b), or the triangle in Figure 2(C).
It can be any shape, such as a hexagon.

The crosspieces 3 in FIG. 1 can be formed by integral molding during molding of the formwork of the present invention described above, but the crosspieces 3 made of synthetic resin may also be attached to required parts after molding only the formwork. good.

Looking at the avatar rate and amount of water removed when concrete is poured using the formwork of this invention and conventional plywood formwork such as plywood, it is found that the large amount of water removed means that the surface strength of concrete is proportionally reduced. It means to increase the number of people.

Such an increase in initial strength has advantages such as early demolding, improved lateral pressure resistance, savings in temporary materials, and increased economic efficiency, as well as improved freezing resistance.

Furthermore, the surface strength of concrete cast using the formwork of the present invention was found to be 1.3 to 1.8 times higher than that of plywood 3 and 28 days after casting.

<Effects of the Invention> As explained above, if the formwork of the present invention is used, activated cement particles will not pass through, and bubble permeability will be perfected to allow dewatering and water permeation to occur at an appropriate speed, resulting in concrete pouring. It is possible to reliably prevent the formation of air bubbles, blisters, and fine irregularities on the concrete surface, resulting in a beautiful concrete surface.

Therefore, in the summer, it has an insulating effect and suppresses moisture evaporation, increasing the curing effect and preventing the occurrence of cracks on the surface of poured concrete in areas with large temperature differences between day and night, and rain and shine, such as in mountainous areas. .

In addition, excess water and air bubbles in the poured concrete are removed through the open-cell synthetic resin board, which has water permeability and air permeability, so the hardening speed of the concrete in contact with the resin board becomes faster and the initial strength increases. This increases the number of times the mold is used, making it possible to remove the mold at an early stage.

[Brief explanation of drawings]

Figure 1 is a perspective view showing the structure of the formwork of the present invention, Figure 2 (
a) to (c) are front views showing the hollow shape of the inside of the formwork of the present invention. A... Formwork 1... Open-cell synthetic resin board 2.2a, 2b, 2cm hollow part 3... Crosspiece Za Zb lC

Claims (3)

[Claims] (1) A concrete casting form made of an open-cell synthetic resin board with water permeability and air permeability, the inside of which is hollow, and crosspieces installed at required intervals on one of the outside surfaces. (2) The formwork for concrete pouring according to claim (1), wherein the internal hollow part of the formwork made of an open-cell synthetic resin plate has a cross section of an arbitrary shape and is partitioned into a plurality of strips. (3) Claim (1) in which the crosspiece attached to one outside surface of the formwork made of open-cell synthetic resin board is integrally molded.
Formwork for concrete pouring as described.