JP4443909B2 - Lined board for concrete formwork and manufacturing method thereof - Google Patents

Description

The present invention relates to a concrete form lining board to be attached to a molding inner surface of a concrete form used when placing concrete, a method for manufacturing the same, a concrete form and a method for cleaning the concrete form.

Conventionally, a lot of technology has been proposed to efficiently discharge excess water and mixed air through the porous sheet when the concrete is hardened by using a concrete mold with a porous sheet attached to the inner surface of the molding. Has been.

  As such a porous sheet, a sheet in which a synthetic resin sheet (water-impermeable sheet) in which many fine holes are formed is bonded to the surface of a nonwoven fabric (water-permeable layer) is known (Patent Document 1, Patent Document 2). reference).

When the porous sheet is used, surplus water and mixed air can flow into the nonwoven fabric through the fine holes of the synthetic resin sheet and be discharged to the outside through the nonwoven fabric.
Thereby, surplus water is removed, the water-concrete ratio is improved, and avatar formation of the concrete surface generated by the mixed air is prevented, and high-quality concrete can be formed.

  In particular, since the surface in contact with the concrete is a synthetic resin sheet, the fibers of the nonwoven fabric are not peeled off and adhere to the concrete surface, so that it can be finished into a good concrete surface and the porous sheet is reused. There was an advantage of being able to.

  However, in the conventional porous sheet, since the nonwoven fabric is used as the water permeable layer, there is a problem that flexibility is generated as a whole, and the strength (rigidity) of the porous sheet cannot be secured.

Moreover, concrete large number of fine holes formed in the synthetic resin sheet (impermeable sheet) are formed at regular shape and regular arrangement by press working or the like, as a trace of these numerous fine holes avatar There was a problem that it was left on the surface and the appearance was damaged.

Conventionally, a polyester fiber board has been proposed in which a polyester nonwoven fabric is formed into a board shape by hot press molding a polyester nonwoven fabric and then cold pressing (see Patent Document 3).
This polyester fiber board is used as a core material for mattresses or as a building material. It is not used as a lining board for concrete formwork. There is no proposal of a lining board for a concrete formwork in which a synthetic resin film having holes formed thereon is bonded.
JP-A-1-158179 JP-A-6-81458 JP 2003-89959 A

The present invention has been made to solve the above-described problems, and ensures rigidity as a whole, and eliminates the bad appearance due to the traces of many fine holes remaining on the concrete surface as avatars. while, it is possible to finish a smooth concrete surface without roughness, and has an object to provide excessive water and lining board for concrete formwork aerated can the be efficiently discharged and a manufacturing how .

In order to solve the above-mentioned problems, a concrete form liner board according to the present invention (Claim 1) is a concrete form liner board attached to a molding inner surface of a mold body, and is composed of a main fiber and a low melting point fiber. The synthetic fiber cotton mat is formed by compressing and molding the synthetic fiber cotton mat by hot press molding with a synthetic resin film superimposed on one or both sides of the synthetic fiber cotton mat mixed with The fiber board is formed by bonding a synthetic resin film formed with a large number of fine holes that allow passage of water and bubbles while preventing the passage of concrete fine particles to the surface of the fiber board. by welding of the low melting fibers with the molding, the surface layer has a rigidity as a whole is hardened, the surface layer is formed with high density in comparison with the inner layer, the alloy Resin film by melt due to the hot press forming, characterized in that a large number of the fine holes are formed in an irregular shape and an irregular sequence.

In the concrete form liner, the hot press molding is performed at a temperature lower than the melting point of the main fiber and at which the low melting point fiber and the synthetic resin film are melted .

The method for producing a concrete form liner according to the present invention (Claim 3) is a method for producing a concrete form liner to be attached to the inner surface of a mold body, comprising a main fiber, a low melting point fiber, by hot press forming in a state in which at one or both sides of the mixed synthetic fiber cotton mat overlaid synthetic resin film, causes melt the low melting fibers of said synthetic fiber cotton mat surface layer, the synthetic resin A hot press process in which a large number of fine holes allowing the passage of water and bubbles while allowing the passage of water and bubbles while preventing the passage of concrete particles by melting the film was formed in an irregular shape and an irregular arrangement, followed by hot press molding. and a cold press forming step of cold press-forming a synthetic resin film and the synthetic fiber cotton mat, thereby compressing molding the synthetic fiber cotton mat On the surface of the to form fiber board, characterized in that to produce a large number of the lining board for concrete formwork construction by bonding synthetic resin film fine holes were formed.

The lining board of the present invention (Claims 1 and 2) can efficiently discharge excess water and mixed air at the time of placing concrete while ensuring the rigidity of the lining board itself.

  In addition, the appearance of many fine holes formed in the synthetic resin film can be eliminated as an avatar on the concrete surface, and a smooth concrete surface without roughness can be finished.

Moreover, because it veneered surface on the synthetic resin film of a fiber board having rigidity as a whole, its useful life long as possible out to increase the number of repeated use.

  In the method for manufacturing a lining board of the present invention (Claim 3), a synthetic resin film can be easily bonded to the surface of a fiberboard having rigidity.

In particular, compression molding of fiberboard, bonding of synthetic resin film, and formation of fine holes in the synthetic resin film can be performed simultaneously by a simple process of hot press molding and cold press molding. The lining board can be formed in a simple process, such as the formation of fine holes in a synthetic resin film by hot press forming and cold press forming without using mechanical means such as a punching press. Can be manufactured .

  The lining board for concrete form of the present invention (hereinafter abbreviated as “lining board”) is used by being attached to the inner surface of the concrete form, and a synthetic resin film is provided on one side (or both sides) of the fiber board. It is formed by bonding.

The fiber board is formed by compression molding a synthetic fiber cotton mat.
This synthetic fiber cotton mat has a melting point of 260 ° C., 50 to 90% polyester fiber having a thickness of 2 to 40 denier, and 50 to 10% of a low melting point polyester fiber having a softening point of 75 ° C. called a binder. This is formed by passing through a loosening step and a plowing step to form a nonwoven fabric and laminating the nonwoven fabric into several layers. In addition, it is preferable in terms of recycling to use recycled fibers from waste PET bottles as the polyester fibers.

Examples of the synthetic resin film include a polyethylene film, a polypropylene film, an ethylene vinyl acetate film, a vinyl chloride film, a polyethylene terephthalate film, and a polyamide film .
Among these, a polyethylene film, a polypropylene film and a polyethylene terephthalate film are particularly preferable as a material for the synthetic resin film used in the present invention because they have good water resistance, good workability and are inexpensive. The thickness of this synthetic resin film is usually 10 to 100 μm.

Then, an adhesive such as hot melt is applied to the back surface of the synthetic resin film, and is laminated on one surface of the synthetic fiber cotton mat.
Thus, in a state where the synthetic resin film is overlapped on one side of the synthetic fiber cotton mat, this is hot press-molded at a temperature of 150 to 200 ° C. and a pressure of 3 to 30 MPa for 30 to 120 seconds.
After this hot press forming, cold press forming is continuously performed at a temperature of 20 to 35 ° C. and a pressure of 3 to 30 MPa for 30 to 120 seconds.

  A lining board in which a synthetic resin film having a large number of fine holes is bonded to the surface of a fiber board formed by compression-molding the synthetic fiber cotton mat by hot press molding and cold press molding. Can be molded.

At this time, since the surface portion of the synthetic fiber cotton mat is heated first by the heat from the hot plate at the time of hot press molding, the low melting point polyester fiber is melted only at the surface portion and the fibers are welded together. It is possible to compress the compressed state.
Thereby, while the surface layer is hardened and has rigidity as a whole, a fiber board in which the surface layer is formed at a higher density than the inner layer can be formed.
In addition, the thickness of the fiber board to be molded can be freely controlled by inserting a metal spacer having a desired thickness between the upper and lower pressure surfaces during hot press molding and cold press molding.
Although there is no restriction | limiting in particular in the thickness of this fiber board, Usually, it is 1-5 mm, preferably about 3 mm in consideration of discharge property of excess water and bubbles, rigidity, and the like.

In addition, a synthetic resin film is firmly bonded to the surface of the fiber board by an adhesive such as hot melt, and at this time, as described above, the low melting point polyester fiber is melted in the surface portion of the synthetic fiber cotton mat. Along with the film resin is melted synthetic resin film, a large number of fine holes in the resin film is molded.
In addition, with the hot press molding, the synthetic resin film is welded to the low melting point polyester fiber melted at the surface portion of the synthetic fiber cotton mat, so even without applying an adhesive such as hot melt on the back surface of the synthetic resin film, Although there is a decrease in bonding force, a synthetic resin film can be bonded to the surface of the fiber board.
The fine hole is formed so as to open to a size that allows passage of water and bubbles while preventing the passage of fine concrete particles. Specifically, the hole has a size of about 0.1 mm to 0.6 mm. It is formed with an irregular shape and an irregular arrangement in diameter. In addition, the hole diameter of a fine hole can be adjusted with the temperature and time of hot press molding.
The fine holes are usually formed at a density of about 20 to 200, preferably 30 to 150, more preferably about 30 to 100 per 1 cm 2. By forming the fine holes at such a density, Water and air in the concrete can be efficiently discharged without reducing the strength of the synthetic resin film.

The lining board formed in this manner is attached to the inner surface of the concrete mold by an adhesive or mechanical means, and at this time, is attached so as to contact the concrete on which the synthetic resin film is placed.
A release agent may be applied to the surface of the synthetic resin film.

In the concrete placement work, a lining board forms a framework of a concrete form attached to the molding inner surface, and concrete is placed in the molding space.
The dead weight of the placed concrete acts as a side pressure on the concrete formwork, and excess water and mixed air bubbles in the concrete flow into the fiber board through the fine holes formed in the lining board. .
At this time, since the fine hole is formed in a size that allows passage of water and bubbles while preventing the passage of concrete fine particles, excess water and contamination are mixed while regulating the outflow of the concrete component (NORO). Only air can be discharged.

The surplus water and mixed air that has flowed into the fiber board through the fine holes penetrates from the surface layer of the fiber board to the inner layer. At this time, the surface layer has a higher density than the inner layer. Therefore, the resistance received when passing through the surface layer is reduced when passing through the inner layer.
Thereby, surplus water and mixed air that has passed through the surface layer are sufficiently diffused in the inner layer, and dehydration and deaeration can be promoted, and in this fiber board, water remains in a retained state, The concrete can be cured under suitable wet conditions.

In this way, after curing for a predetermined period, the concrete mold is demolded. At this time, since the synthetic resin film having a smooth surface is in contact with the concrete surface, the mold can be easily demolded.
Further, since the mixed air is deaerated, there is no generation of avatar due to bubbles, and the surface property corresponds to the smoothness of the surface of the synthetic resin film. Moreover, since the curing conditions are good, the strength of the resulting concrete structure is high.

In particular, when concrete molding, a large number of fine holes are transferred to the concrete surface, the trace is not entirely remain on the concrete surface as an avatar.
As a result, it is possible to eliminate the poor appearance due to the traces of the fine holes remaining on the concrete surface as avatars, and to finish the surface with a smooth concrete surface without roughness.

The demolded formwork is required to be washed and used repeatedly. However, in the lining board of the present invention, since the synthetic resin film is laminated on the surface, the concrete component is the synthetic resin film. It only adheres to the surface and does not enter the fiberboard.
Therefore, when washing, an organic acid (for example, manufactured by Toa Oil Kogyo Co., Ltd .: Samtec R-7: 6 times diluted and used on the surface of the lining board (synthetic resin film), manufactured by Nox Co., Ltd .: Norotol: 2 to 3 times diluted) is applied by hand brush, roller brush, spray application, etc., after sufficiently neutralizing the concrete components for a predetermined time, and then washed with a car wash brush etc. Without damaging the resin film, the adhering concrete component can be easily dropped, and the opening of the fine holes formed in the synthetic resin film can be restored.
Thus, since the synthetic resin film is bonded to the surface of the fiber board having rigidity as a whole, the lining board of the present invention has a long service life and can increase the number of repeated uses.

FIG. 1 is a cross-sectional view of a state in which the concrete formwork of the present invention is framed, FIG. 2 is an enlarged view showing part A of FIG. 1, and FIG. 3 is an enlarged view showing part B of FIG.
This concrete formwork 1 is for constructing a concrete groove having a substantially U-shaped cross section at the site construction. The outer vertical formwork 10, 10, the outer bottom formwork 11, the inner vertical formwork 12, 12, the inner ceiling It is framed by the formwork 13.
Of these molds, the lining board 2 is attached to the respective molding inner surfaces of the outer vertical mold 10, the inner vertical mold 12, and the inner ceiling mold 13 excluding the outer bottom mold 11 with an adhesive.

The lining board 2 is formed by bonding a synthetic resin film 21 to one side of a fiber board 20.
The fiber board 20 is manufactured by blending 30% low-melting polyester fiber having a thickness of 4 denier with 70% polyester fiber having a thickness of 17 denier, mixing, mixing, and then performing a lamination process. By doing so, a synthetic fiber cotton mat (primary mat) having a thickness of 30 mm is formed.
Then, a polypropylene film is used as the synthetic resin film 21, and the synthetic resin film 21 coated with hot melt on the back surface is laminated on one side of the synthetic fiber cotton mat, and in that state, at a temperature of 180 ° C. and a pressure of 10 MPa for 1 minute. After hot press molding, a lining board 2 having a width of 900 × width of 900 × thickness of 3 mm was formed by cold press forming at a temperature of 35 ° C. and a pressure of 10 MPa for the same time as the hot press. .
In addition, as the material of the fiber board 20, polyester fiber, which is a recycled fiber of waste plastic bottles, is used.

  The lining board 2 formed in this way allows a large number of water and bubbles to pass through the surface of the fiber board 20 formed by compression molding the synthetic fiber cotton mat while preventing the passage of concrete fine particles. The synthetic resin film 21 in which the fine holes 22 (shown in FIG. 6) are formed is bonded together.

  4 shows a microstructure photograph of the surface layer of the fiber board 20 in the lining board 2 when observed with a scanning electron microscope (150 times), and FIG. 5 scans the inner layer of the fiber board 20 in the lining board 2. FIG. 6 is a microstructure photograph when the surface of the synthetic resin film 21 is observed with a scanning electron microscope (150 times).

As shown in FIG. 4, in the surface layer of the fiber board 20, the polyester fibers are fused at the contact portion.
On the other hand, as shown in FIG. 5, in the inner layer of the fiber board 20, the fusion phenomenon at the contact portion of the polyester fiber is not recognized.

That is, since the surface portion of the synthetic fiber cotton mat is heated first by the heat from the hot plate during hot press molding, the melting of the low-melting polyester fiber on the surface portion becomes strong and the fibers are welded together. Then, by cooling and fixing this in the cold pressing step, it is possible to compress the both surface surfaces into a cured state.
Thereby, while the surface layer hardens | cures and it has rigidity as a whole, the fiber board 20 by which the surface layer was formed in high density compared with the internal layer can be formed.

  Further, the synthetic resin film 21 is firmly bonded to the surface of the fiber board 20, and at this time, the low melting point polyester fiber melts in the surface portion of the synthetic fiber cotton mat. The film resin is melted, and a large number of fine holes 22 are formed in the synthetic resin film 21 as shown in FIG.

As shown in FIG. 1, the lining board 2 manufactured as described above is formed on the inner surfaces of the outer vertical frame 10, the inner vertical frame 12, and the inner ceiling frame 13 with the synthetic resin film 21. It is placed so as to face the molding space S and to be in contact with the concrete.
Since the inner ceiling mold 13 is disposed so as to cover the upper surface of the molding space S, surplus water and bubbles that try to escape upward from the cast concrete are received by the inner ceiling mold 13. As a result, the avatar due to bubbles is generated on the molding surface formed by the inner ceiling mold 13.
Therefore, as shown in FIG. 3, a large number of molds arranged so as to cover the upper surface of the molding space S such as the inner ceiling mold 13 penetrate the mold body 13a from the molding inner surface to the outer surface. Through-holes 13b are formed, and excess water and bubbles are discharged through the through-holes 13b. Thereby, retention of excess water and bubbles can be prevented.

  In addition, although said Example is an example of the concrete formwork which constructs a concrete groove by field construction, when constructing the concrete retaining wall 3, as shown in FIG. Use the formwork 1, use it in the haunch, construct concrete structures such as civil engineering walls and architectural walls, etc., and form pipes, box culverts, and other concrete secondary products It goes without saying that the configuration of the present invention can be applied to a concrete formwork for this purpose.

It is sectional drawing of the state which framed the concrete formwork of this invention. It is an enlarged view which shows the A section of FIG. It is an enlarged view which shows the B section of FIG. It is a microstructure photograph when the surface layer of the fiber board in a lining board is observed with a scanning electron microscope. It is a microstructure photograph when the inner layer of the fiber board in a lining board is observed with a scanning electron microscope. It is a micro structure photograph when the surface of a synthetic resin film is observed with a scanning electron microscope. It is sectional drawing which shows the example which applied the formwork of this invention to the inclined wall surface of a concrete retaining wall.

DESCRIPTION OF SYMBOLS 1 Concrete formwork 10 Outer vertical formwork 11 Outer bottom formwork 12 Inner vertical formwork 13 Inner ceiling formwork 13b Through hole 13a Formwork body 2 Lined board 20 Fiber board 21 Synthetic resin film 22 Fine hole 3 Concrete retaining wall S Molding space

Claims (3)

A concrete formwork lining board to be attached to the molding inner surface of the formwork body,
The synthetic fiber cotton mat is compression-molded by hot press molding with a synthetic resin film overlaid on one or both sides of a synthetic fiber cotton mat in which main fibers and low-melting fibers are mixed, and then cold press molding. A synthetic resin film formed with a number of fine holes allowing the passage of water and bubbles while preventing the passage of concrete particles is formed on the surface of the fiber board formed by being bonded,
The fiber board is formed by welding the low melting point fiber accompanying the hot press molding, the surface layer is cured and has rigidity as a whole, and the surface layer is formed at a higher density than the inner layer,
The synthetic resin film is a concrete form lining board characterized in that a large number of the fine holes are formed in an irregular shape and an irregular arrangement by melting due to the hot press molding . The lining board for concrete form according to claim 1, wherein the hot press molding is performed at a temperature lower than the melting point of the main fiber and the low melting point fiber and the synthetic resin film melt . A method of manufacturing a concrete formwork lining board to be attached to a molding inner surface of a formwork body,
By hot press forming in a state in which at one or both sides overlaid synthetic resin film of synthetic fiber cotton mat of a mixture of main fibers and low melting point fibers, the low melting fibers of said synthetic fiber cotton mat surface layer A hot pressing step of melting and forming a large number of fine holes with an irregular shape and an irregular arrangement allowing the passage of water and bubbles while melting the synthetic resin film and preventing the passage of concrete fine particles;
Subsequently, a cold press molding step of cold press molding the synthetic fiber cotton mat and the synthetic resin film that have been hot press molded,
With
Producing a lining board for a concrete form having a structure in which a synthetic resin film formed with a large number of fine holes is bonded to the surface of a fiber board formed by compression molding the synthetic fiber cotton mat. A method for producing a lining board for a concrete formwork.

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