WO1994020704A1

WO1994020704A1 - Water-permeable concrete formwork

Info

Publication number: WO1994020704A1
Application number: PCT/JP1994/000316
Authority: WO
Inventors: Shohei Masui; Seiji Suzuki; Munehisa Togami; Takeo Kitayama
Original assignee: Sumitomo Chemical Company, Limited
Priority date: 1993-03-03
Filing date: 1994-02-28
Publication date: 1994-09-15
Also published as: JPH06254825A; EP0646684A4; EP0646684A1

Abstract

A water-permeable concrete formwork of thermo-plastic resin characterized in that a thermoplastic resin layer having water permeability is provided on at least one of the surfaces of a basic thermoplastic resin layer, whereby removal of moisture from placed concrete is promoted by absorption and/or permeation of moisture of said concrete by and/or through said water-permeable thermoplastic resin layer, thereby making it possible to significantly reduce the curing time of concrete.

Description

Fine Permeable concrete formwork technology field

TECHNICAL FIELD The present invention relates to a thermoplastic resin water-permeable concrete form having a surface layer having water permeability. Background technology

Conventionally, a large amount of formwork made of wood, such as southern seawood, has been used as concrete formwork. However, in view of global environmental problems in recent years, the development of concrete formwork that replaces wood is required, and a typical example is concrete made of thermoplastic resin. Formwork is proposed o

This thermoplastic resin concrete formwork is usually made of a fiber reinforced thermoplastic resin sheet whose panel surface is reinforced with a thermoplastic resin sheet or a fiber such as glass fiber. The sheet is manufactured by melting a thermoplastic resin or a mixture of the same with glass fiber and molding the sheet into a sheet shape. The surface of the sheet is completely covered with the resin. I'm wearing

The concrete formwork using such a thermoplastic resin as the panel surface does not cause global environmental problems due to the large amount of use of wood, and is made of wood-based concrete. It is lighter than a single formwork, and concrete is cast using the formwork. It has many advantages, such as excellent isolation from concrete later.

However, on the other hand, since the panel surface in contact with the concrete does not absorb or transmit moisture, there is a so-called curing period until the concrete is completely cured after casting. The disadvantage was that it would be longer. Disclosure of the invention

Thus, the present inventors have satisfied the characteristics required for a concrete formwork, and have been able to shorten the curing period of the concrete. As a result of studies to develop a concrete formwork, the present invention has been achieved.

That is, the present invention provides a thermoplastic resin permeable concrete formwork comprising a thermoplastic resin layer and a thermoplastic resin layer having water permeability provided on at least one surface thereof. It is provided. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a cross-sectional structure of a water-permeable concrete formwork of the present invention in which a base material thermoplastic resin layer is a flat plate and a water-permeable thermoplastic resin layer is provided on both sides thereof.

FIG. 2 shows the cross-sectional structure of the water-permeable concrete mold of the present invention in which the base thermoplastic resin layer is a flat plate and has a water-permeable thermoplastic resin layer on one surface.

Figure 3 shows that the base thermoplastic resin layer is a flat plate with ribs. The cross-sectional structure of the water-permeable concrete form of the present invention having a water-permeable thermoplastic resin layer on its flat plate side is as follows:

FIG. 4 shows a cross-sectional structure of the water-permeable concrete mold of the present invention in which the base thermoplastic resin layer is a flat plate with a rib and has a water-permeable thermoplastic resin layer on the rib side.

FIG. 5 shows a water-permeable concrete formwork of the present invention in which the base thermoplastic resin layer has a plastic step ball structure, and has water-permeable thermoplastic resin layers on both sides. Fig. 6 shows the cross-sectional structure of the water-permeable concrete of the present invention in which the base thermoplastic resin layer has a plastic corrugated cardboard structure with small holes, and has water-permeable thermoplastic resin layers on both surfaces. Fig. 7 shows a cross-sectional structure of the mold. Fig. 7 shows a flat plate in which the base material thermoplastic resin layer is provided with a water guide groove, and a water permeable component of the present invention having a water permeable thermoplastic resin layer on the water guide groove side flat plate. The cross-sectional structure of the lip form is shown below.

The numbers in the figure have the following meanings.

1 Substrate thermoplastic resin layer

2 Water-permeable thermoplastic resin layer

3 Live

4 small holes

5 BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

The permeable concrete formwork made of thermoplastic resin of the present invention, Thermoplastic resin layer as base material for concrete formwork

(Substrate thermoplastic resin layer) 1 and water-permeable thermoplastic resin layer (water-permeable thermoplastic resin layer) provided on its surface

And 2.

The structure of the base thermoplastic resin layer is not particularly limited, and may be a flat plate (FIGS. 1 and 2) or a large number of ribs whose cross sections are comb-shaped. (Figs. 3 and 4) or a plastic corrugated cardboard type with a ladder-shaped cross section (Fig. 5). In addition, as a result of these deformations, for example, grooves 5 for water introduction are provided on the surface of the base thermoplastic resin layer within a range that does not cause a significant decrease in strength (Fig. 7). A small hole 4 is formed in the resin layer (Fig. 6), and the moisture from the cast concrete is permeable through the thermoplastic resin layer through these grooves and small holes. Materials The backside of the thermoplastic resin layer or the gap between the ribs can be guided to the gaps between the ribs to facilitate the removal of water and shorten the curing period of the concrete.

The material constituting such a base thermoplastic resin layer is not particularly limited as long as the material satisfies the strength of the concrete formwork. Polyethylene, lip. Pyrene, ABS resin-. Thermoplastic resins such as vinyl chloride resin, PMMA, nylon, and polycarbonate resin are examples. Polypropylene is preferred in terms of heat resistance, strength, economy, etc. Pyrene is preferred.

Such a base thermoplastic resin layer is formed of such a thermoplastic resin. Although it is made of fat, various reinforcing fibers, for example, glass fibers, are added to the resin to improve the mechanical and physical strength of the concrete formwork. It is very effective to use a fiber reinforced thermoplastic resin blended at about 70% by weight.

Of course, regardless of the presence or absence of such reinforcing fibers, various compounding agents such as stabilizers, colorants, and fillers that are usually compounded in a thermoplastic resin may be compounded. Absent.

The water-permeable thermoplastic resin layer is provided on the surface of the base thermoplastic resin layer, and the surface of the base thermoplastic resin layer is in contact with the base thermoplastic resin layer when used as a mold. The surface on the side in contact with the concrete is generally smooth in many cases, but may be on the rib side as shown in Fig. The water-permeable thermoplastic resin layer may be provided not only on one side of the base thermoplastic resin layer but also on both sides thereof.

In the present invention, the water-permeable thermoplastic resin layer is in contact with the cast concrete surface, absorbs water in the cast concrete, and transmits water through the same layer. Any material having a function of accelerating the removal of water from the concrete by permeating it may be used as long as it has water permeability. An expanded fiber-filled thermoplastic resin sheet obtained by expanding a filled thermoplastic resin sheet (stub bubble sheet) in the thickness direction is preferably used. You.

In this stampable unit, glass fiber is usually used as a fiber to be filled, but other fibers such as carbon fiber and alumina fiber may be used, and there is no particular limitation. No.

The thermoplastic resin is not particularly limited as long as it is compatible with these fibers and has the strength and chemical resistance required for the formwork material. More specifically, for example, the same as the above-described base thermoplastic resin layer, for example, polypropylene, polyethylene, ABS resin, vinyl chloride resin, PMMA, nylon , Poly-force—A thermoplastic resin such as a bone resin is exemplified, and in particular, polypropylene is preferably used.

The fiber content in such a removable sheet is usually from 10 to 70% by weight, preferably from 20 to 50% by weight. A typical example of such a sheet is a dry stampable sheet made of a blend of glass fiber and continuous fiber in polypropylene resin. Wet process star that contains glass fibers of a few millimeters to about 30 millimeters long in a sheet, polypropylene resin or polyethylene phthalate resin. Sheets referred to as removable sheets are known, and these sheets are usually sold as melt-pressed sheets.

Any of these sheets can be used as a raw material for expanded fiber-filled thermoplastic resin sheets, but with a larger expansion ratio. The wet processable sheet, which can obtain a sheet having excellent permeability and excellent water permeability without extremely lowering the mechanical strength, is preferably used.

An expanded fiber-filled thermoplastic resin sheet suitable as a water-permeable thermoplastic resin layer is obtained by expanding the above-described stampable sheet in the thickness direction by expansion molding. Almost no water permeability.

Examples of the expansion molding method include a method of simply heating and expanding a stub bubble sheet and then cooling, and a method of heating and expanding in a predetermined space having a certain expansion ratio and then cooling. There are various methods, but the desired expansion ratio can be set accurately.Moreover, from the point of view of workability, the pre-heated and expandable sheet is pre-heated and expanded to a thickness that achieves the predetermined expansion ratio. Compressing and cooling in this state is most preferred.

Here, the expansion ratio is represented by the ratio of the thickness of the sheet after expansion to the thickness of the stub bubble sheet before expansion. For example, the sheet after expansion is the thickness of the sheet before expansion. When the thickness is twice, the expansion ratio becomes twice.

The expansion ratio is preferably as high as possible to improve water permeability, but if the expansion ratio is too high, the surface strength of the concrete form cannot be secured. Usually less than 3 times, preferably less than 2.5 times.

The lower limit is not particularly limited, since water permeability appears when the expansion ratio exceeds 1 times, but it is usually necessary to obtain good water permeability. It is 1.05 times, preferably 1.1 times.

A method of providing a water-permeable thermoplastic resin layer on the surface of the base thermoplastic resin layer and integrating them is as follows: the water-permeable thermoplastic resin layer and the base thermoplastic resin layer that have been manufactured in advance are bonded with an adhesive. A method of joining the two by ultrasonic bonding, a method of melting the adhesive interface of both resin layers and heat-sealing them, and a method of expanding the stub bubble sheet by heating and expanding. A method in which the thermoplastic resin layers are overlapped and pressed together to form an expanded fiber-filled thermoplastic resin sheet and heat-sealed at the same time. Both upper and lower prefabricated expanded fiber-filled thermoplastic resin sheets are used. A basic thermoplastic resin layer is formed by placing in a mold, supplying a molten thermoplastic resin between the sheet and the mold surface, closing the mold, and press-cooling. At the same time, the surface is filled with expanded woven fiber thermoplastic There are various methods such as a method of producing a thermoplastic resin water-permeable concrete form to which a resin sheet is heat-sealed.

When a thermoplastic resin filled with fibers such as glass fiber is used as a base material as a deformation, only the surface layer of the base material on the side in contact with the concrete is heated and expanded. Then, by compressing or cooling without compressing, changing the surface portion of the base thermoplastic resin layer to a water-permeable thermoplastic resin layer involves joining work. It is also possible to provide a water-permeable thermoplastic resin layer.

In the thermoplastic resin permeable concrete formwork of the present invention, the resin forming the water permeable thermoplastic resin layer is made of a heat-transferable base material. When the same resin is used to form the plastic resin layer, the joining between the two resin layers becomes stronger and the strength as a concrete form is improved. In addition, the workability is good, and the recycled concrete formwork can be recycled.

In the thermoplastic resin permeable concrete formwork of the present invention, the overall thickness of the formwork is such that the required strength as the formwork is obtained. There is no particular limitation, usually about 10 to 70 bandits.However, the workability during use, especially in relation to the wood-based concrete formwork that has been used more frequently than before. From the above, it is 10 to 15 mm in the case of only the flat plate as shown in FIGS. 1, 2 and 7, and the base thermoplastic resin as shown in FIGS. 3 to 6. When the layer has a rib structure, it is desirable that the thickness be in the range of 62 to 65 mm.

Also, the thickness of the water-permeable thermoplastic resin layer cannot be expected to have a corresponding effect even if it is too thick, and the thickness of the entire mold is too thick. It is usually 15 thighs or less, preferably 10 mm or less, and the lower limit is not particularly limited as long as it has water permeability, but is usually 0.5 thighs, preferably 1 bandit.

When the concrete is cast using the thermoplastic resin permeable concrete formwork of the present invention, the moisture in the concrete is removed by the water permeable thermoplastic resin layer. As a result, the moisture in the concrete is removed and the curing period of the cast concrete is greatly shortened. It has the effect of being reduced.

Example

Hereinafter, the present invention will be described in more detail with reference to examples, but it is to be understood that the present invention is not limited to these examples.

The test method in each case is as follows.

Bending test: Performed by a three-point support method in accordance with JIS K7203.

Appearance evaluation: Evaluated based on the number of pinholes (diameter 3 mm or more) per 0.25 square meter of concrete surface after mold release. The relationship between the number of pinholes and the evaluation is as follows.

Less than 150 binholes ◎ (good)

150 to 300 〇 (average of wooden formwork)

301 to 500 X (inferior Ri by wooden formwork) Curing Time: co down click time it takes for the compression strength of the co-down click rie bets rie preparative droplet after casting is ing to 6 0 kg / cm ² (Moisture elimination time) was measured.

Compressive strength: 100 mm in diameter from the cast concrete wall, 200 mm in height, 200 cm of columnar sample is withdrawn, and load is applied when the column is broken by applying pressure from the upper surface. Was measured.

Rebound strength: The concrete surface was measured with a Schmidt hammer (unit: R〇)

Example 1 A stampable sheet containing 30% by weight of glass fiber with an average fiber length of 12 mm and an average glass fiber diameter of 10, and the matrix resin is polypropylene. (Capra Sheet Co., Ltd .: Cape La Sheet, weight per unit area: 1750 g Zm ² , thickness 5 mm) is heated in a heating furnace until the surface of the sheet reaches 210 ° C. did. The thermal expansion sheet inflated up to 3 times in the thickness direction, set so in the mold of the plate, and a cooling press in earthenware pots by a thickness of 3 hide pressure 1 0 kg / cm ² As a result, an expandable molded sheet of a stampable sheet having an expansion ratio of 2 was obtained.

The expanded molded sheet obtained above has a plastic cardboard-like structure with a top plate thickness of 0.5 thigh, rib thickness of 0.5 mm, rib spacing of 5 mm, and a total thickness of 5 mm. A concrete type with a cross-sectional structure as shown in Fig. 5 with a width of 60 Omm, a height of 90 Omm, and a thickness of 11 mm, bonded to both sides of the article with an adhesive I got the frame.

Table 1 shows the physical properties of the obtained concrete formwork.

This concrete formwork is used for the front and back, and the sides are made of wood timber plywood with a width of 300 thighs. After assembling the concrete formwork, the concrete consisting of cement Z water Z sand Z pebble 3 Z 2/8 no 10 (weight ratio) is poured into the concrete form An experiment was conducted on the installation of the tank.

Table 2 shows the results.

Example 2 Stanno, containing 30% by weight of glass fiber with an average fiber length of 12 thighs and an average glass fiber diameter of 10, and a matrix resin of polypropylene. ,. A bull sheet (Cape La Sheet Co., Ltd .: Cape La Sheet, weight per unit area: 400 g / m ² , thickness: 3.4 mm) is heated, and the obtained heat-expanded sheet is cooled. By lapping, an expanded molded sheet having a width of 600 mm, a length of 900 mm and a thickness of 4 mm was obtained. The expansion ratio of this sheet is 1.2 times.

Consists of upper and lower molds, the lower mold is a 100-ton mold that is designed to be able to mold ribs with a thickness of 5 mm and a height of 10 mm at intervals of 504 Using a vertical press forming machine with a clamp, a concrete formwork with ribs was manufactured by the following method. The above-mentioned expansion molding sheet is placed between the upper and lower molds, and between the sheet and the lower mold surface, 20 weight of glass fiber is fed from a molten resin passage provided in the lower mold. % Of polypropylene resin (Sumitomo Chemical Co., Ltd .: Sumitomo Novel), and then the mold is closed, pressed, cooled, and cooled. With a thickness of 7 mm (the upper layer is an expanded molded sheet layer with a thickness of 4 mm), which is integrally joined with a rib of 5 thighs and a height of 10 mm with a rib force of 54 mm. A concrete formwork with ribs having a cross-sectional structure as shown in Fig. 3 was obtained.

Table 1 shows the physical properties of the obtained concrete formwork.

Using this concrete formwork, an experiment of placing concrete was performed in the same manner as in Example 1.

Table 2 shows the results. Example 3

Stanno, which has 30% by weight of glass fiber having an average fiber length of 12 mm and an average glass fiber diameter of 10, and has a matrix resin of polypropylene. A bull sheet (Cape La Sheet Co., Ltd .: Cape La Sheet, weight per unit area: 2000 g / m ² , thickness: 1.7 mm) is heated, and the obtained heat-expanded sheet is cooled. As a result, an expanded molded sheet having a width of 60 mm, a length of 900 mm, and a thickness of 3 mm was obtained. The expansion rate of this sheet is 1.8 times.

This expanded molded sheet was bonded to one side of a polymethylmethacrylate plate (Sumitomo Chemical Co., Ltd .: Sumipex sheet) with a thickness of 8 thighs with an adhesive, as shown in Fig. 2. A concrete formwork having the cross-sectional structure as shown was obtained.

Table 1 shows the physical properties of the obtained concrete formwork.

Using this concrete formwork, a concrete placing test was conducted in the same manner as in Example 1.

Table 2 shows the results.

Comparative Example 1

The same raw material stampable sheet as used in Example 1 was adhered to both sides of the 5-thigh bra staircase with the same adhesive as used in Example 1 with an adhesive to a thickness of 11 mm. A concrete formwork having the structure shown in Fig. 5 was obtained.

Table 1 shows the physical properties of the obtained concrete formwork.

Using this concrete formwork, a concrete placing test was performed in the same manner as in Example 1. The results are shown in Table 2.

table 1

Table 2 Appearance Curing pressure during curing ^ degree Rebound altitude

(14 days after casting) (R0) Number of binholes (hrs) (kg / cm ² ) Example 1 125 ◎ 18 207 21 Example 2 110 ◎ 21 216 24 Example 3 118 ◎ 16 195 23 Comparative example 1 425 X 65 205 18 Industrial applicability

By providing the water-permeable thermoplastic resin layer on the base thermoplastic resin layer, the advantage of the plastic concrete formwork can be maintained without deteriorating the advantages of the conventional concrete formwork. It has the advantage that the curing period can be greatly reduced compared to plastic concrete formwork.

Claims

The scope of the claims

1. A thermoplastic resin permeable concrete form comprising a base thermoplastic resin layer and a thermoplastic resin layer having water permeability provided on at least one of its surfaces.

2. The water-permeable concrete formwork according to claim 1, wherein the water-permeable thermoplastic resin layer is an expansion molded sheet of a fiber-filled thermoplastic resin sheet.

3. The permeable concrete formwork according to claim 2, wherein the expansion ratio is 1.05 to 3 times.

4. The permeable concrete formwork according to claim 2, wherein the fibers are glass fibers.