JP3192770B2 - Forming sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet to be affixed to a surface of a formwork used for placing concrete, which is in contact with concrete. More specifically, the present invention relates to a formwork-attaching sheet that can efficiently discharge excess water and mixed air when concrete poured into the form is hardened, thereby forming suitable curing conditions. .

[0002]

BACKGROUND OF THE INVENTION When constructing a concrete building, the quality of concrete can be improved by reducing the amount of water used and reducing the water / cement ratio. However, as the water / concrete ratio decreases, the workability during concrete placement decreases, and in practice, a certain amount of excess water is used to ensure the workability. As a method of constructing a high-quality concrete building from concrete having a high water / cement ratio, a method of discharging excess water and curing after casting is adopted.

For example, a method in which concrete is poured into a mold having a porous material adhered to the inner surface of the mold and excess water and air bubbles are discharged from the porous material to the outside (Japanese Patent Application Laid-Open No. Sho 60/1985) JP-A-43,528), and a mold in which this porous material is made into a multilayer has already been proposed (see JP-A-61-274,046).

[0004] However, since the porous material as described above is often formed from a fiber aggregate such as a nonwoven fabric, after the concrete is hardened, the concrete becomes porous even if the mold is removed. There is a problem that it is difficult for the porous material to penetrate into the inside of the material and peel off from the concrete surface.

As a sheet for solving the above-mentioned problems, Japanese Patent Application Laid-Open No. 1-158,179 discloses a sheet in which a resin film having fine pores on the surface of a nonwoven fabric or the like is bonded.

Japanese Patent Application Laid-Open No. 3-17,351 discloses that a fiber whose surface is coated with a low-melting polymer compound is used to bond the low-melting polymer compound to one surface of a nonwoven fabric using the bonding agent as a bonding agent. There is disclosed a form-adhering sheet in which a film made of a low-melting polymer compound as an agent is formed, and fine holes are formed in the film.

[0007] In the form-adhering sheet in which the above-mentioned nonwoven fabric is directly covered with a film having fine pores, excess water and air penetrate into the nonwoven fabric through the fine pores, move through the nonwoven fabric, and are discharged. However, since the outlet of the micropore is in direct contact with the nonwoven fabric, the outlet of the micropore may be blocked by the fibers of the nonwoven fabric. When a resin film having fine holes is bonded with an adhesive, a part of the fine holes may be closed by the adhesive.

Further, as the nonwoven fabric used in such applications, it is necessary to use a nonwoven fabric which is woven to a certain degree and has a high stiffness in order to secure the strength of the sheet itself. There is a problem that the performance of discharging water or air is reduced.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a concrete form attaching sheet capable of efficiently discharging surplus water and air in concrete.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a synthetic resin film having a large number of micropores and a non-woven fabric are bonded by a number of filaments having an adhesive component on the surface thereof.
Provided is a sheet for applying a formwork, characterized in that a water-permeable layer is formed between the synthetic resin film and the nonwoven fabric by the filament.

In the sheet for attaching a formwork of the present invention, the synthetic resin film having a large number of fine holes and the nonwoven fabric are not directly adhered to each other, but are formed on the surface of the filament through the filament. It is bonded by an adhesive. This thread-like body functions as a kind of spacer for bonding the synthetic resin film and the nonwoven fabric, and for forming a gap between the synthetic resin film and the nonwoven fabric. The gap formed between the synthetic resin film and the non-woven fabric using the filament as a spacer acts as a water-permeable layer for discharging excess water and air in the concrete flowing out of the fine holes.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Next, the sheet for attaching a formwork of the present invention will be specifically described with reference to examples. FIGS. 1, 2 and 4 schematically show the structure of the sheet for applying a formwork of the present invention. FIG. 1 is a perspective view of a sheet for attaching a formwork having a notch according to the present invention, and FIG. 2 is a cross-sectional view of the sheet. FIG. 4 is a cross-sectional view of the sheet for attaching a formwork of the present invention having an adhesive layer.

The sheet for attaching a formwork of the present invention comprises a synthetic resin film 1, a filament 2, and a nonwoven fabric 3. Many fine holes 4 are formed in the synthetic resin film 1.
Since the synthetic resin film comes into contact with concrete, it is preferable that the synthetic resin film is formed of a synthetic resin having high alkali resistance and high water resistance so as not to be decomposed even by contact with concrete. Examples of such a synthetic resin include polyethylene, polypropylene, ethylene vinyl acetate, vinyl chloride, polyethylene terephthalate, polyamide and polyimide. Among these, particularly polyethylene, polypropylene and polyethylene terephthalate have good water resistance,
It has good processability and is inexpensive, and is particularly preferable as a material for the synthetic resin film used in the present invention. The thickness of the synthetic resin film 1 is usually 10 to 100 μm.

A number of fine holes 4 are formed in such a synthetic resin film 1. The fine holes 4 penetrate the synthetic resin film 1. The pore diameter of the fine pores 4 is such that moisture and air pass therethrough but components (excluding water) forming the concrete to be poured do not pass through,
Usually, it is smaller than the average particle size of the fine aggregate mixed in the concrete. The diameter of the fine holes 4 is specifically 1.0 mm.
It is preferably 0.1 mm or more in consideration of water and air permeability.

The synthetic resin film 1 is 1 cm ²
Per hit, usually 20 to 200, preferably 30 to 15
It has 0, more preferably 30 to 100 micropores 4. By having micropores at such a density, moisture and air in concrete can be efficiently discharged without reducing the strength of the synthetic resin film.

The fine holes 4 penetrate the synthetic resin film 1 and reach the water-permeable layer 5. The water-permeable layer 5 is a layer formed between the synthetic resin film 1 and the non-woven fabric 3, and is bonded to the synthetic resin film 1 and the non-woven fabric 3 by a large number of filaments 2 having an adhesive component on the surface. It is formed by doing. As shown in FIG. 3, the filament 2 has an adhesive component 7 on the surface of an aggregate of a large number of filaments 6. Here, the filament 6 may be any of a synthetic resin, an inorganic fiber and the like. Particularly, in the present invention, glass fibers are preferable. The filament may be formed of, for example, a single filament in addition to the multiple filaments as described above.

Although various adhesives can be used for the adhesive component 7, it is preferable to use an adhesive having heat adhesiveness. Examples of adhesives having such heat adhesion include polyester, ethylene-vinyl acetate copolymer,
Styrene / butadiene copolymer, styrene / isoprene copolymer, styrene / ethylene / butylene copolymer and (meth) acrylic acid (co) polymer can be mentioned. FIG. 3 shows a preferred embodiment of the filament.

The filament 2 may be in the form of an aggregate having any of a circular cross section, an elliptical shape, and a polygonal shape. For example, in the case of an elliptical shape, a short diameter is usually 0.1 to 2 mm, preferably It has a cross-sectional diameter of 0.2 to 1 mm and a major diameter of 0.2 to 4 mm, preferably 0.4 to 2 mm, and usually 0.1 to 2 mm, preferably 0.2 to 1 mm for a circular shape. It has a cross-sectional diameter. By using the thread 2 having such a cross-sectional diameter, an effective gap as the water-permeable layer 5 can be formed between the synthetic resin film 1 and the nonwoven fabric 3.

The thread 2 adheres the synthetic resin film 1 and the nonwoven fabric 3 and also functions as a spacer for forming the water-permeable layer 5. For this reason, the arranged filaments 2 are arranged so as to secure the necessary adhesive strength between the synthetic resin film 1 and the nonwoven fabric 3 and to form a gap necessary for efficiently discharging water and air. Need to be done. For this reason, the thread 2 is disposed between the synthetic resin film 1 and the nonwoven fabric 3 at an interval of usually 1 to 20 mm, preferably 2 to 10 mm. If the distance is too small, the drainage efficiency of the water-permeable layer 5 decreases, and the probability that the fine holes formed in the synthetic resin film 1 are closed by the filaments 2 increases. Also, if this interval is too wide,
It becomes difficult to secure the adhesive strength between the synthetic resin film 1 and the nonwoven fabric 3.

The filament 2 is stretched between the synthetic resin film 1 and the nonwoven fabric 3 only in the vertical direction when the sheet of the present invention is attached to the concrete formwork, and the synthetic resin film 1 and the nonwoven fabric 3 are joined together. Can be glued. In addition, the thread-shaped body 2 may be knitted in a net shape.

There is no particular limitation on the nonwoven fabric 3 bonded by the thread 2 as described above, and various nonwoven fabrics conventionally used can be used. That is, in the sheet for applying a form of the present invention, water and air are discharged through the water-permeable layer 5, but water and air are discharged not only from the water-permeable layer 5 but also from the nonwoven fabric. It is preferable to use a nonwoven fabric having drainage / exhaustability, since the drainage / exhaust efficiency is improved as a result. Short fibers forming such a nonwoven fabric include various short fibers such as polyester fiber, polypropylene fiber, regenerated cellulose fiber, polyvinyl alcohol fiber, vinylon fiber, rayon fiber, nylon fiber, and composite fiber. Non-woven fabrics using short fibers can also be used.

The form-fixing sheet of the present invention comprises a synthetic resin film 1 and a nonwoven fabric 3 with an adhesive 7 on the surface of the filament 2.
Are bonded, and the synthetic resin film 1 and the nonwoven fabric 3 are not directly bonded, so that the water-permeable layer 5 is formed. Accordingly, the sheet of the present invention is used as the nonwoven fabric so that an effective water-permeable layer is formed between the nonwoven fabric 3 and the synthetic resin film 1 by bonding the synthetic resin film 1 and the nonwoven fabric 3 with the filament 2. It is desirable to use a material that does not contain a component that causes the nonwoven fabric 3 and the synthetic resin film 1 to directly adhere to each other by an adhesion operation at the time of formation.

The thickness of the nonwoven fabric is not particularly limited, but is usually 0.1 to 3 mm, preferably 0.3 to 1.5 mm.
The sheet for attaching a formwork of the present invention is a sheet in which the synthetic resin film 1 and the nonwoven fabric 3 are bonded by the thread 2 as described above, and the water-permeable layer 5 is formed by the thread 3. However, as shown in FIG. 4, the adhesive layer 8 can be further provided on the surface of the sheet where the nonwoven fabric 3 is in contact with a mold (not shown).

Here, the adhesive components forming the adhesive layer 8 include an acrylic adhesive and a rubber adhesive, but contain as little as possible an unsaturated monomer having a polar group and a vinyl monomer. A (meth) acrylic adhesive composed of a copolymer containing an acrylic ester as a main component is preferable. These adhesives have good water resistance and excellent alkali resistance.

The adhesive layer made of the above adhesive usually has a thickness of 5 to 100 μm. Moreover, the sheet | seat for formwork affixing of this invention may have the release agent layer 9 in the surface which the synthetic resin film 1 contacts concrete, as shown in FIG. By forming the release agent layer in this way,
After curing, the concrete and the sheet for applying a formwork of the present invention can be easily peeled off, and the number of times of repeated use of the sheet for applying a formwork of the present invention dramatically increases.

Here, the components forming the release agent layer include:
Examples include silicone oils, silicone resins, and metal soaps of higher fatty acids. In the release agent layer 9 as described above, similarly to the fine holes 4 formed in the synthetic resin film 1, the water-permeable layer 5 in which excess water or the like in the concrete is formed by the filaments 2 and the nonwoven fabric Needless to say, the fine holes 4 are formed so as to be discharged through the inside 3.

The release agent layer usually has a thickness of 0.05 to 5.0 μm.
m. The sheet for formwork attachment of the present invention,
Laminating the synthetic resin sheet 1, the filament 2, and the non-woven fabric 3, and bonding the adhesive to the adhesive on the surface of the filament by heating to a temperature at which the synthetic resin sheet does not undergo thermal deformation. Can be manufactured. At this time, it can be manufactured by forming the fine holes 4 in the synthetic resin film 1 and the release layer 9 provided as required, and then arranging the filaments and the nonwoven fabric 3 and thermocompression bonding.

The adhesive layer 8 is formed by bonding the synthetic resin film 1 and the nonwoven fabric 3 with the thread 2 as described above, and then coating the nonwoven fabric 3 on the surface in contact with the mold. As a method of applying the adhesive, a conventionally known method can be adopted.

As shown in FIG. 5, the sheet 11 for attaching a formwork of the present invention is attached to a surface of a concrete formwork 10 on which concrete is cast. When the sheet 11 for attaching a formwork has the adhesive layer 8, the form 1
Affixed to the surface of No. 0, and when there is no adhesive layer, as shown in FIG. 6, apply an adhesive on a non-woven fabric, or apply an adhesive to the sheet bonding surface of the mold, An adhesive is applied to the sheet 13 for applying a formwork.

The concrete 12 is cast in the space formed by the formwork to which the formwork attaching sheet is attached as described above. The weight of the concrete 12 cast in this way acts as a lateral pressure on the sheet of the present invention affixed to the formwork, and the excess water in the concrete is provided on the release agent layer 9 and the synthetic resin film 1 by the lateral pressure. The water flows into the water-permeable layer 5 through the fine holes 4. The water-permeable layer 5 is a gap between the synthetic resin film 1 and the nonwoven fabric 3 secured by the filament 2, and most of surplus water is discharged through the water-permeable tank 5, Is discharged through the nonwoven fabric. Air contained in the concrete 12 as air bubbles is also discharged in the same manner as the surplus water.

After the excess water and air are discharged in this way, the concrete gradually hardens, and the lateral pressure acting on the side wall of the formwork decreases, so that no water is discharged, and the concrete is hardened into the concrete. Since a certain amount of water remains, the concrete can be cured under appropriate wet conditions.

After curing for a predetermined period in this way, the mold with the sheet attached to the surface is removed. Not only when the sheet for attaching a formwork of the present invention has a release agent layer on the surface, but also when it does not have a release agent layer, the surface of the synthetic resin film is smooth, so that the mold can be easily removed. With little damage to the sheet on the surface.

Further, the concrete cured by sticking this sheet has no avatar due to air bubbles and has a surface property corresponding to the smoothness of the surface of the synthetic resin film. In addition, since the curing conditions are good, the strength of the obtained concrete structure is high.

After curing the concrete as described above, the removed formwork can be used repeatedly without replacing the surface sheet.

[0035]

In the sheet for attaching a formwork of the present invention, a water-permeable layer is formed between a synthetic resin film having a large number of micropores and a non-woven fabric by interposing a thread-like material, so Surplus water and air flow out through the micropores into the aquifer and are discharged through the aquifer and the nonwoven fabric. Therefore, surplus water and air can be discharged more efficiently than a conventional form-sticking sheet in which a film having micropores is directly attached to a nonwoven fabric. By efficiently discharging surplus water, concrete can be cured under very good conditions. Further, since air can be efficiently discharged, generation of avatars on the surface of the concrete structure can be prevented.

Furthermore, since the sheet for attaching a formwork of the present invention is formed of a synthetic resin film having a smooth surface, the surface property of the concrete structure is good. Furthermore, the removal of the formwork from the concrete structure is facilitated. When the release agent layer is formed on the surface, the mold can be removed very efficiently, and breakage of the sheet for applying the mold can be effectively prevented. Therefore, the formwork to which the sheet of the present invention is attached can be used repeatedly without replacing the sheet.

Further, since the thread forming the sheet for attaching a form of the present invention is made of, for example, glass fiber, the thread also serves as a reinforcing material for the sheet for attaching a form. The sticking sheet is also excellent in strength.

Further, by providing the adhesive layer, the sheet for attaching a form can be easily attached to a concrete form. By using the formwork with the formwork sticking sheet having such a configuration, for example, by sticking it to a wooden concrete formwork, it is possible to use the wooden formwork for a long period of time, Effective utilization can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic view schematically showing a sheet for applying a formwork of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a cross section of the sheet for applying a formwork of the present invention.

FIG. 3 is a cross-sectional view schematically showing a cross section of a sheet for pasting a form of another embodiment.

FIG. 4 is a cross-sectional view illustrating an example of a cross-section of a filamentous body.

FIG. 5 is a cross-sectional view showing a state where concrete is cast on a formwork to which a formwork attaching sheet of the present invention having an adhesive layer is attached.

FIG. 6 is a cross-sectional view showing a state where concrete is poured into a formwork to which the formwork attaching sheet of the present invention having no adhesive layer is attached.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Synthetic resin film 2 ... Filament 3 ... Nonwoven fabric 4 ... Micropore 5 ... Water-permeable layer 6 ... Filament 7 ... Adhesive component 8 ... Adhesive layer Reference Signs List 9 release agent layer 10 formwork 11 formwork sticking sheet having adhesive layer (having adhesive layer) 12 concrete 13 formwork paste sheet (adhesive Not having)

Claims (4)

(57) [Claims] A non-woven fabric and a synthetic resin film having a large number of fine holes are bonded to each other by a number of filaments having an adhesive component on the surface thereof. A sheet for applying a formwork, wherein a water-permeable layer is formed between the sheet and a nonwoven fabric. 2. Between the synthetic resin film and the nonwoven fabric, 1
2. The sheet according to claim 1, wherein a large number of filaments are arranged at intervals of about 20 mm. 3. The sheet according to claim 1, wherein a release agent layer is provided on a surface of the synthetic resin film which comes into contact with concrete. 4. The sheet for applying a formwork according to claim 1, wherein an adhesive layer is provided on a surface of the nonwoven fabric which comes into contact with the formwork.