JPH0853935A - Permeable concrete formwork and its manufacturing method - Google Patents

Abstract

(57) [Summary] [Structure] On the top plate of the concrete mold made of thermoplastic resin,
A water-permeable concrete formwork in which a water-permeable sheet is stretched over the entire surface of the top plate without adhering, and the end portions of the sheet are joined to the outer peripheral side wall surface of the concrete formwork. [Effect] Excessive water in the cast concrete can be easily removed, the curing period can be shortened, and concrete having high hardness can be obtained. Further, since the water-permeable sheet can be refilled, the concrete formwork as the base material can be reused.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a water-permeable concrete mold made of a thermoplastic resin.

[0002]

2. Description of the Related Art It is well known that concrete formwork is often used for concrete and mortar driving in construction and civil engineering. In such concrete and mortar (hereinafter referred to as concrete) casting, in order to remove excess water in the cast concrete, shorten the curing time of the placed concrete and improve the hardness of the concrete surface. , A concrete formwork in which a sheet having a water-permeable function (hereinafter referred to as a water-permeable sheet) is adhered to the surface of the top plate with an adhesive, or a water-permeable sheet is attached to a thermoplastic resin top plate (Japanese Patent Application No. Flat 5
No. 43013) was used.

However, in a concrete formwork in which a sheet having a water-permeable function is adhered to the surface of the top plate with an adhesive, the adhesive used for the adhering cannot enter the water-permeable sheet to exert a sufficient water-permeable function. In a concrete formwork in which a water-permeable sheet is pasted and integrated on the top plate part, molten resin enters the water-permeable sheet to reduce the water-permeable function in the manufacturing process of the frame, or depending on the type of the molten resin or the water-permeable sheet used. Has a problem that the water-permeable sheet may be melted by the heat of the molten resin during molding, and the water-permeable function may be deteriorated. Furthermore, in these concrete formwork, if once the slag penetrates into the permeable sheet and causes clogging, it is desirable to replace the permeable sheet and reuse it. There is a problem that the form itself cannot be used because it is difficult to peel it off.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The present inventors can efficiently remove excess water in the cast concrete to shorten the curing period without lowering the performance as a concrete formwork, and to obtain concrete having excellent surface hardness. As a result of studying a concrete formwork, the present invention has been completed.

[0005]

[Means for Solving the Problems] That is, the present invention provides a top plate portion of a concrete form made of a thermoplastic resin, which is a base material,
A water-permeable concrete formwork and thermoplastic material in which a water-permeable sheet is stretched over the entire surface of the top plate without adhering, and the ends of the sheet are joined at the outer peripheral side wall surface of the concrete formwork. A water-permeable sheet is stretched on the top plate portion of the resin concrete formwork via the cushion layer without being adhered to the entire surface of the cushion layer, and the end portion of the sheet is on the outer peripheral side of the concrete formwork. It is intended to provide a water-permeable concrete formwork joined by wall surfaces.

The present invention will be described in detail below. The water-permeable concrete mold made of a thermoplastic resin of the present invention basically comprises a top plate portion (1) formed of a thermoplastic resin as a base material and a sheet (2) having water permeability, and the sheet. Is stretched on the top plate surface without being adhered to the entire surface,
Further, the sheet has an end portion (3) joined to the outer peripheral side wall surface (4) of the concrete formwork. In addition to the above basic structure, the concrete formwork may have a cushion layer (5) having the same width and length as the top plate between the top plate surface and the water-permeable sheet. In this case, the cushion layer may be adhered to the entire surface of the top plate, but the water-permeable sheet on it is stretched without being adhered to the entire surface of the cushion layer, and the end portion of the water-permeable sheet is wrapped so as to wrap the cushion layer. Are joined at the outer peripheral side wall surface of the concrete formwork.

With such a structure, the water permeable sheet floats above the top plate in the top plate portion that is in direct contact with the poured concrete, and excess water in the placed concrete is permeable to the water permeable sheet and the water permeable sheet. It is easily removed from the gap between the sheet and the top plate portion, and particularly when the cushion layer is provided between the surface of the top plate portion and the water permeable sheet, the effect is more remarkable.

The thermoplastic resin concrete formwork as the base material in the present invention may be formed only from a flat plate corresponding to the top plate portion (FIGS. 1 to 3), and its cross section is comb-like. The top plate may have a structure in which a plurality of reinforcing ribs (9) are provided on one surface (Fig. 5), and the shape thereof is not particularly limited as long as it is used as a concrete formwork, In terms of surface, workability, etc., it is practically preferable to have a shape in which a rib is provided on one side of a flat plate as shown in FIGS.

In the water-permeable concrete formwork of the present invention, the water-permeable sheet is not adhered to the entire surface of the top plate,
Depending on the type of water permeable sheet and the size of the concrete formwork, for example, the water permeable sheet and the top plate may be locally bonded at the central part of the top plate, etc. Can be prevented. However, even in such a case, it is necessary to avoid providing continuous adhesive parts, and to reduce the adhesive parts as much as possible so as not to impair the water permeability when using the concrete formwork. is necessary. In order to prevent such extra adhesion, it is preferable to stretch the water-permeable sheet on the top plate surface evenly and slightly so that the top plate surface does not become loose.

The end portions of the water-permeable sheet stretched on the surface of the top plate are joined to each other on the outer peripheral side wall surface of the concrete form. Here, the outer peripheral side wall surface means that the concrete formwork is a flat plate (top plate).
If it is, it is the mouth part (Figs. 1-3),
If the concrete formwork has a structure in which a plurality of reinforcing ribs are provided on one side of the top plate and the ribs are provided vertically along the outer circumference of the top plate, The outer peripheral surface (FIGS. 4 and 5), which is the top end of the top plate when the rib is provided inside the outer periphery of the top plate (not shown). The joining of the end of the permeable sheet to the outer peripheral side wall surface of the concrete formwork may be performed on the entire outer peripheral side wall surface or may be performed partially, but if the joint area is too small, the permeable sheet will be joined to the concrete formwork. Since the adhesive strength becomes small, generally, when the outer peripheral side wall surface is composed only of the top end of the top plate, the entire surface of the top end is joined (Fig. 1)
In the case of a structure in which the ribs are provided vertically along the outer circumference of the top plate (FIG. 5), the ribs are partially joined over the entire outermost peripheral surface or at least in a range beyond the portion corresponding to the mouth end. . If, for example, the outer peripheral side wall is composed of only the top of the top plate with a small thickness and the area (joint area) of the top end is small, fold the water-permeable sheet terminal on the back of the top plate and join the top part with the top end. You may join simultaneously also on the back surface of a board. (Fig. 2)

When a water-permeable sheet is stretched on the top plate of the concrete form via a cushion layer, the width of the cushion layer does not extend beyond the surface of the top plate and is not too small. And the length is preferably the same as the top plate, and the thickness of the cushion layer is arbitrary. The cushion layer may be adhered to the entire surface of the top plate, may be simply placed without being adhered, or may be partially adhered at an arbitrary position. In order to fix the to the top plate, it is preferable that the whole surface is adhered to the top plate at least at a part thereof. The water-permeable sheet is stretched from above the cushion layer and joined in the same manner as described above.

The thermoplastic resin as the base material of the thermoplastic resin water-permeable concrete formwork of the present invention is not particularly limited as long as it maintains the strength of the concrete formwork.
For example, polyethylene, polypropylene, ABS resin,
Examples thereof include vinyl chloride resin, PMMA, nylon, polycarbonate, etc., and polypropylene is particularly preferable from the viewpoint of heat resistance, strength, economy and the like. Such a thermoplastic resin may contain various reinforcing fibers such as glass fibers in an amount of about 10 to 70% by weight in order to improve the mechanical and physical strength of the concrete formwork. The resin may optionally contain stabilizers, colorants, fillers and the like which are usually blended with the resin.

The water-permeable sheet is not particularly limited as long as it is a sheet having a water-permeable function, but a fiber bundle obtained by converging hundreds to thousands of fibers made of a thermoplastic resin such as polyethylene or polypropylene is woven into a cloth shape, and Sheets made by introducing unidirectionally arranged resin fiber bundles during weaving are preferably used from the viewpoint of strength and water permeability, and other various fiber cloths such as polyethylene fiber cloth, polypropylene fiber cloth, and foamed sheets are used. it can. Further, as a special example, a water absorbent resin sheet can also be used for the same purpose.

The cushion layer is used as a cushioning material between the top plate portion of the thermoplastic resin concrete form which is the base material and the water permeable sheet, and for improving the water permeable function of the water permeable sheet. As the cushion layer,
For example, various inorganic fiber sheets (for example, glass fiber sheet, carbon fiber sheet), non-woven fabric, woven fabric, paper, etc. are used, but it is preferable that they do not lose their shape by absorbing water during use. Nonwoven fabrics and woven fabrics are preferably used. Such a cushion layer is usually used as it is, but when a fiber sheet, a non-woven fabric, a woven fabric or the like is used, a resin sheet may be attached to one side or both sides thereof. This resin sheet is effective for facilitating the adhesion of the cushion layer to the top plate portion of the thermoplastic resin concrete mold which is the base material, and for protecting the cushion layer.

As a method for producing the water-permeable concrete formwork of the present invention, a water-permeable sheet is stretched by placing a cushion layer on the surface of a top plate of a thermoplastic resin concrete formwork produced in advance or without placing it. An example is a method of joining the water permeable sheet end to the concrete formwork outer peripheral side wall surface with an adhesive, or a method of joining by ultrasonic bonding or heat fusion at the adhesive interface between the water permeable sheet end and the concrete formwork outer peripheral side wall surface. However, it is practically advantageous to use the integral molding method, in which the concrete form is manufactured by injection molding, injection press molding, press molding, etc., and at the same time, the water permeable sheet is attached. In the case of manufacturing a water-permeable concrete formwork having a cushion layer between and, an integral molding method by injection press molding or press molding is advantageous.

When manufacturing by injection press molding or press molding, a conventionally known method is applied as a basic molding method itself. For example, using the openable male and female molds (6, 7) designed to have a predetermined product shape, the cavity part is the same as the top plate part of the concrete form between both molds in the open state. A cushion layer (5) having a width and a length is placed, and a water permeable sheet (2) larger than the top plate and having a size that can be joined to the outer peripheral side wall surface of the concrete formwork is placed thereon (FIG. 6). Next, the molten thermoplastic resin (8) heated to the melting temperature or higher was supplied from the mold on the cushion layer side via the molten resin supply passage (10) provided in the male mold (FIG. 7). After that, the mold is clamped (FIG. 8), or the mold is clamped while being supplied, and then cooled. According to this method, it is necessary to select the type and thickness of the cushion layer so that the molten resin does not penetrate the cushion layer and pass through the cushion layer to reach the water permeable sheet. When the cushion layer and the water-permeable sheet are joined in a spot shape, it is sufficient to previously provide the cushion layer with small holes corresponding to the joining positions and through which molten resin can pass. Thus, according to this method, the top plate portion of the thermoplastic resin concrete formwork as the base material and the cushion layer are adhered to the entire surface by heat fusion, and at the same time, the water-permeable sheet covering the upper portion of the cushion layer is the cushion layer if desired. Although it may be spot-joined,
The water permeable sheet is wrapped around the cushion layer without being bonded to the entire surface of the cushion layer, and the sheet end is bonded to the outer peripheral side wall surface of the concrete formwork by heat fusion.

In the water-permeable concrete mold of the present invention, the thickness is not particularly limited as long as the strength required for the mold is obtained, and it is usually about 10 to 70 mm, but it is more frequently used than before. Due to the combination with the existing wood-based concrete formwork and the simple replacement, it is 10 to 15 mm if it consists only of flat plate parts.
When it has a rib structure, the total thickness including the rib height is preferably about 62 to 65 mm.

[0018]

When concrete is placed using the water-permeable concrete formwork of the present invention, excess water in the concrete easily causes a water-permeable sheet or a space between the water-permeable sheet and the concrete form top plate portion. Since it is permeated and eliminated, the curing period of the concrete is shortened, and concrete having high hardness can be obtained. In addition, when the cushion layer is provided between the water permeable sheet and the concrete form top plate portion, the function of absorbing and transmitting water by the cushion layer is increased and the effect is further improved. Furthermore, since the water-permeable sheet is basically adhered only to the outer peripheral side wall surface of the concrete formwork, it can be easily peeled off from the top plate portion,
It is also possible to re-use the permeable sheet and reuse it.

[0019]

The present invention will be described in more detail with reference to the following examples, but it goes without saying that the present invention is not limited thereto. The concrete placing test and the evaluation test were carried out by the following methods. Concrete pouring method: width 600mm, length 1800mm
Concrete formwork is used on the front and back sides, and wood plywood with a width of 300 mm is used on both sides. Horizontal x height x width = 600
Assembling a concrete formwork of × 1800 × 300mm, in which cement / water / sand / pebbles = 3/2/8/1
Pour fresh concrete consisting of 0 (weight ratio) and leave for 1 week. Curing time: After pouring the concrete, the amount of water discharged from between the pouring concrete surface and the top plate surface of the concrete form in contact with the concrete surface was measured. (Measurement time is 150 minutes after placing concrete) Rebound hardness: One week after placing concrete, the concrete form was removed and the concrete surface was measured with a Schmidt hammer. (Unit: RO) In addition, the measurement is in the lateral center of the concrete surface (3 from both ends).
00 mm), 250 mm, 900 mm from the top
And 1550 mm, and made the upper part, the central part and the lower part, respectively.

Example 1 600 mm wide on the plane of the male mold between the opened male and female molds.
mm, length 1800 mm, papermaking glass fiber sheet (glass fiber sheet having an average glass fiber length of 13 mm and an average fiber diameter of 9 mm produced by a wet papermaking method and having a basis weight of 75 g / cm ² ) A water-permeable sheet (a sheet in which polypropylene fiber bundles are knitted in a cross shape and a polypropylene fiber bundle is sandwiched in one direction between the two cross-shaped sheets) which is 30 mm larger in length and width than the above sheet After overlapping so that each side was 15 mm larger than the glass fiber sheet (FIG. 6), the space between the male and female molds was adjusted so that the cavity clearance was 7 mm. Average fiber length 7 mm, average fiber diameter 13 m
Polypropylene containing 27% by weight of glass fiber of m (Sumitomo Chemical Co., Ltd .: Sumitomo Noblene AX568) was supplied to a plasticizer, and heated and melted at 230 ° C. to mix the glass fiber and polypropylene so as to be uniform. 10 kg of this molten glass fiber-containing polypropylene was supplied from a molten resin supply passage provided in a male mold (FIG. 7), and a pressing surface pressure was 8
After the mold is clamped at 8.8 kgf / cm ² (FIG. 8) and cooled, the outermost layer is a water-permeable sheet and the outermost layer is a glass fiber sheet as a cushion layer as shown in FIG. The top plate part provided and the top plate having a large number of intersecting linear ribs on its back surface has a thickness of 4.3 mm, and the total thickness including the ribs is 62.5 mm (however, the thickness of the water-permeable sheet and the glass fiber sheet is included. 60) width
A thermoplastic resin water-permeable concrete mold having a length of 0 mm and a length of 1800 mm was obtained. In this concrete formwork, the glass fiber sheet, which is the cushion layer, was integrally bonded on the entire surface of the top plate portion of the base material, but the water-permeable sheet above it was not adhered to the cushion layer at all, The edge of the sheet was adhered with a width of about 15 mm over the entire circumference of the outer peripheral side wall of the concrete formwork. Using the obtained concrete formwork, a concrete placing test was conducted, and the evaluation results shown in Table 1 were obtained.

Comparative Example 1 A water-permeable concrete mold made of a thermoplastic resin was obtained in the same manner as in Example 1 except that a glass fiber sheet for papermaking was not used and only a water-permeable sheet having a width of 600 mm and a length of 1800 mm was used. In this concrete formwork, the water-permeable sheet was integrally joined to the entire top plate portion of the base material. Using the obtained concrete formwork, conduct a concrete placing test,
The evaluation results shown in Table 1 were obtained.

Comparative Example 2 A water-permeable concrete form made of a thermoplastic resin according to Example 1 using only polypropylene containing molten glass fiber without using both a papermaking glass fiber sheet and a water permeable sheet. Got Using the obtained concrete formwork, a concrete placing test was conducted, and the evaluation results shown in Table 1 were obtained.

[0023]

[Brief description of drawings]

FIG. 1 shows a partial cross section of a water-permeable concrete formwork comprising a top plate portion and a water-permeable sheet according to the present invention.

FIG. 2 shows a partial cross section of a water-permeable concrete formwork of the present invention comprising a top plate portion and a water-permeable sheet.

FIG. 3 shows a partial cross section of a water-permeable concrete formwork of the present invention comprising a top plate portion, a cushion layer and a water-permeable sheet.

FIG. 4 is an external view of the water-permeable concrete formwork of the present invention in which a rib is provided on one surface of a top plate portion and a water-permeable sheet is stretched on the other surface via a cushion layer, as viewed from the rib side.

5 is a partial cross-sectional view of the water-permeable concrete formwork shown in FIG.

FIG. 6 shows an outline of a manufacturing process of a water-permeable concrete formwork of the present invention.

FIG. 7 shows an outline of a manufacturing process of a water-permeable concrete formwork of the present invention.

FIG. 8 shows an outline of a manufacturing process of a water-permeable concrete formwork of the present invention.

[Explanation of symbols]

1: Flat plate (top plate part) 2: Water-permeable sheet 3: Water-permeable sheet end part 4: Concrete mold outer peripheral side surface 5: Cushion layer 6: Female mold 7: Male mold 8: Molten thermoplastic resin 9: Rib 10: molten resin supply path

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takehito Tezuka 1-3-2 Shibaura, Minato-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Katsuhiko Tsujino 500-1 Zensho-cho, Izumi-shi, Osaka Tsujino Stock Association In-house

Claims (5)

[Claims] 1. A water-permeable sheet is stretched on a top plate portion of a thermoplastic resin concrete form without being adhered to the entire surface of the top plate portion, and an end portion of the sheet is a concrete mold. A water-permeable concrete formwork characterized by being joined at the outer peripheral side wall surface of the frame. 2. A water-permeable sheet is stretched on a top plate portion of a thermoplastic resin concrete frame without being adhered to the entire surface of the cushion layer via a cushion layer, and an end portion of the sheet. A water-permeable concrete formwork, characterized in that is joined at the outer peripheral side wall surface of the concrete formwork. 3. A sheet having water permeability is a sheet obtained by sandwiching a sheet in which thermoplastic resin fibers are arranged in one direction while weaving a cloth woven cloth made of a thermoplastic resin fiber bundle. The water-permeable concrete formwork according to claim 1 or 2, which is characterized. 4. The water-permeable concrete formwork according to claim 2, wherein the cushion layer is a non-woven fabric or a fiber sheet. 5. A cushion layer having the same width and length as the surface of a concrete mold made of a thermoplastic resin resin is placed between the male and female molds in the opened and closed state, and the cushion layer is further provided on one side surface of the cushion layer. A water-permeable sheet is placed so as to cover the entire surface of the layer so that its end portion can overlap the outer peripheral side wall surface of the mold, and the thermoplastic resin serving as the base material is supplied in a molten state from the cushion layer side,
The method for producing a water-permeable concrete mold according to claim 2, wherein the mold is clamped and cooled.