JPH0726713A - Concrete form - Google Patents

Abstract

PURPOSE:To increase the amount of drainage at the time of the placement of concrete, and also to increase the compressive strength of concrete by forming drain passages for passing drain from the inside being in contact with concrete to the outside, on the outer periphery of a form. CONSTITUTION:On the outer periphery of a concrete form 1, drain passages 2 for passing drain from the inside being in contact with concrete to the outside are formed. Further, the drain passage 2 is formed in a straight-line shape passing from the inside being in contact with concrete to the outside. As the material of the concrete form 1, plywood or an iron plate is used. When the concrete form 1 of an iron plate is used, the cross-sectional area of the drain passages 2 is increased. When the concrete form 1 is extremely large, drain passages 2 are provided to the places other than the outer peripheral part of the concrete form 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The concrete formwork of the present invention relates to a sheet-applying concrete formwork used for placing concrete.

[0002]

2. Description of the Related Art It is already known that a sheet-attached concrete formwork is effective for deaeration and dehydration when pouring concrete, improves concrete strength, and improves surface finish. As a sheet for concrete formwork,
An example thereof is described in Japanese Patent Laid-Open No. 5-1470.

An example of concrete formwork is described in, for example, Japanese Unexamined Patent Publication No. 5-39667.
Installing a drainage passage in the concrete formwork will improve the drainage capacity. However, the concrete formwork of this example has a disadvantage that the structure is complicated and the manufacturing cost is high.
In addition, when fine particles such as sand are clogged in the internal passage for drainage, it is very difficult to clean. Further, in order to maintain the strength of the concrete form, it is necessary to increase the thickness, which is inconvenient for carrying and storing. When using concrete formwork on curved surfaces, the production of concrete formwork is very complicated.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive concrete formwork which promotes drainage and deaeration of a sheet-attached concrete formwork.

[0005]

[Means for Solving the Problems] A sheet to be attached to a concrete formwork has a shape having both drainage and drainage.
In other words, the excess water of concrete uses the sheet as a drainage channel,
Drained at the edge of the formwork. The present inventors have paid attention to the edge of this concrete formwork and completed the present invention. The concrete formwork of the present invention is characterized in that it has a passage for drainage from the inner surface in contact with the concrete to the outer surface at the outer edge portion of the frame.

The drainage passage (hereinafter abbreviated as "drainage passage") from the inner surface in contact with the concrete to the outer surface of the frame at the outer edge portion thereof may be a groove or a hole. The size of this drainage channel is
Usually, the cross-sectional area is 1 mm ² or more and 100 mm ² or less.
If the cross-sectional area of the drainage channel is less than 1 mm ^{2, the} drainage channel is easily clogged and the drainage effect is insufficient. Moreover, the cross-sectional area of the drainage channel is 100 mm.
^If it exceeds ² , the sheet is likely to be torn, and it is necessary to increase the strength of the sheet, which is not preferable. There is also a problem with the strength of the concrete formwork itself. The size of the cross-sectional area of the drainage channel is preferably 5 to 20 mm ² . The cross-sectional shape of the drainage channel is preferably a circle, a square, or a shape close to this in terms of maintaining strength.

The outer edge portion of the concrete form used in the present invention means within 10 cm from the end of the concrete form, or within 10% of the length of the form. It is better to have the drainage channel at the end of the formwork in order not to impair the strength of the formwork. In addition, if there is a framework at the end of the concrete formwork and it becomes expensive to process it at the end, or if the opening of the inner surface that contacts the concrete is blocked by a combination of concrete formwork etc., the above outer edge part It can be processed into

The distance between the drainage channels depends on the cross-sectional area of the drainage channels, but is usually 1 cm or more and 20 cm or less. Even if the distance between the drainage channels is less than 1 cm, there is little improvement in the drainage effect,
The processing cost is high. If the distance between the drainage channels exceeds 20 cm, the amount of drainage will be insufficient even if the cross-sectional area of the drainage channels is 100 mm ² . The distance between the drainage channels is preferably 3 to 10 cm.

The drainage channel leads from the inner surface contacting the concrete to the outer surface, but may be straight. In processing the drainage channel,
It is better to have a straight line. However, the present invention is not limited to this.

The material of the concrete formwork is generally plywood or iron plate, but is not particularly limited. The sheet attached to the concrete formwork has a good drainage property, and may be of a type that uses the sheet as a drainage channel. There is no particular limitation. The sheet is used to cover the drainage channel of the concrete formwork.

When using an iron plate concrete formwork,
Since the sheets are bonded with an adhesive, the larger the cross-sectional area of the drainage channel, the less the clogging by the adhesive. When the concrete formwork is extremely large, a drainage channel may be provided in addition to the outer edge portion of the concrete formwork. 1m usually used
If it is about the width, the drainage channel at the outer edge is sufficient.

[0012]

When the concrete formwork of the present invention is used for placing, the amount of drainage at the time of placing is increased, the compressive strength of concrete is improved, and the finished surface is finely finished.

[0013]

EXAMPLES Further details will be described in Examples.

The amount of drainage of concrete formwork is 0.5: 1: 2: 3 of concrete: water: Portland cement: sand: gravel of a general composition, and per m ² until 2 hours have passed after placing. The amount of wastewater was compared. In addition, the densities of the concrete finishes were compared with the naked eye. For compressive strength of concrete, a test piece is cut out and JIS A110 is used.
According to 8, the test piece 21 days after the placing was measured.

Example 1 A plain weave was used as the first layer, which was prepared by squeezing 1000 denier 152 filaments of polyester multifilament into 20 filaments / inch and wefts 20 filaments / inch. The second layer is polyester semi-dal 2 denier 5
A non-woven fabric having a thickness of 5 mm and a basis weight of 150 gr / m ² produced by needle punching 1 mm and using a heat fusion binder was used. A hot melt type non-woven fabric, which is unlikely to cause clogging, was used for adhesion. This sheet for concrete formwork was attached to the concrete formwork with a stapler, and after placing concrete, the drainage amount and the compressive strength were measured. The finished state was visually observed.

In the concrete formwork used in the test, a drainage channel having a square cross section shown in Table 1 was provided at the end of the concrete formwork parallel to the thickness direction of the formwork. The measurement results are shown in Table 2.
As a comparative product, an ordinary concrete formwork without a drainage channel was used.

[0017]

[Table 1]

[0018]

[Table 2]

[Brief description of drawings]

FIG. 1 shows an example in which a drainage channel is installed at the end of a concrete formwork.

FIG. 2 shows an example in which a drainage channel is installed at the end of a concrete formwork.

FIG. 3 shows an example in which the drainage channels are installed alternately with the drainage channels on the opposite side. When constructing the mold, uniform drainage can be performed from the periphery of the mold by avoiding overlapping with a drainage channel provided in another adjacent mold.

FIG. 4 shows a usage state of FIG.

[Explanation of symbols]

 1, 11 Concrete formwork 2, 12 Drainage channel 3 Drainage channel interval

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoko Fukumoto 483 Edomari, Hofu City, Yamaguchi Prefecture (72) Inventor Yoichi Taniyama 1-5-8-807, Yubuchicho, Miyakojima-ku, Osaka (72) Inventor Masao Hashimoto Hiroshima 4-16-8 Nori, Nishi-ku, Nishi-shi Marui Industry Co., Ltd. (72) Inventor Shinya Miyagawa 4-16-8 Nori, Nishi-ku, Hiroshima-shi Marui Industry Co., Ltd.

Claims (1)

[Claims] 1. A concrete formwork, characterized in that it has a drainage passage from the inner surface in contact with concrete to the outer surface at the outer edge of the frame.