JPH04327652A - Form attaching sheet - Google Patents

Abstract

PURPOSE:To prevent the occurrence of pitting and to enable the reuse of sheets by making a sheet with a permeable layer for removing water and a surface layer consisting of fabric in which intersections of monofilaments with a flat cross section are fused. CONSTITUTION:A surface layer consisting of fabric in which intersections of monofilaments with a flat cross section are fused and a permeable layer which consists of nonwoven fabric, knitted braid, etc., and removes water are bonded, preferably via a bonding layer, to form a sheet for attaching forms. Air bubbles and excess amounts of water are sent to the permeable layer through a gap of surface layer and discharged to the outside through the permeable layer so as to secure water necessary to reinforce the concrete. This provides a smooth surface of surface layer and eliminates pores between the filaments. Therefore, the sheet has high mold drawing property and can be reused repeatedly without damaging the surface of fabric. Also, the occurrence of pitting can be prevented because the opening of fabric of the surface layer is less prone to change.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is capable of repeatedly improving the surface condition of poured concrete after hardening.
It relates to a sheet that is used by being attached to a formwork.

0002

[Prior Art] Conventionally, when constructing a structure by pouring concrete, in order to improve workability, an excessive amount of water is added to the concrete, and after the concrete is poured into the formwork. This excess water was removed by compaction.

However, if excess water is removed by simply compacting, the water collects on the surface of the form together with the air bubbles in the concrete, resulting in traces of air bubbles and so-called water pockmarks on the hardened concrete surface, which deteriorates the aesthetic appearance. Not only was this damaged, but it also contributed to a decrease in durability.

[0004] Therefore, as a method to solve such problems, by pasting a cloth sheet made of core-sheath type composite filament inside the formwork, air bubbles and water are eliminated, and a high-strength material with less pock formation is created. There is a method for obtaining concrete (Japanese Unexamined Patent Publication No. 1-203564).

[0005] However, since this fabric sheet is a single layer, it is difficult to smoothly separate, transport, and eliminate air bubbles and water, and it has not been sufficiently effective in preventing the occurrence of pockmarks. .

[0006] Furthermore, since multifilaments are used, fine powder of concrete milk adheres to the pores between the filaments, resulting in poor demoldability, and when cleaning to completely remove adhering concrete milk, Not only are the filaments cut, scratched, and fluffed, but the opening between the filaments also changes, resulting in noticeable pockmarking, making it difficult to use them repeatedly.

On the other hand, a formwork in which a water-permeable nonwoven fabric and a plain woven fabric with a filtering function are laminated has also been disclosed (Japanese Patent Application Laid-Open No. 63-22966), but this plain woven fabric also has a multifilament structure. , the same problem as above occurred and it was difficult to use it repeatedly.

[0008]

[Problems to be Solved by the Invention] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a formwork pasting sheet that is less likely to cause pockmarks and can be used repeatedly. shall be.

[0009]

[Means for Solving the Problems] The formwork pasting sheet of the present invention comprises at least a water-permeable layer that excludes water and a surface layer made of a fabric in which the intersections of monofilaments having flat cross sections are fused together.

0010

[Function] The fabric of the surface layer of the formwork pasting sheet of the present invention is
Since it is made of monofilament with a flat cross section, the surface layer is smooth, and there are no pores between the filaments like when using multifilament.
Fine powder from concrete milk is difficult to adhere to. Therefore,
The form pasting sheet of the present invention has excellent demoldability, does not require careful cleaning, and does not cause the monofilament to be cut or damaged. Therefore, the surface layer does not become fluffy and the mesh size does not easily change, so pockmarks are less likely to occur and it can be used repeatedly without problems.

Moreover, since the surface layer fabric is fused at the intersections of the monofilaments, the surface layer has excellent dimensional stability, and when demolding or washing, the surface layer fabric is fused. Since changes in opening are less likely to occur, it is possible to further suppress the occurrence of pockmarks.

[0012] Furthermore, the sheet for pasting formwork of the present invention separates air bubbles and water using the surface layer, and transports and removes air bubbles and water using the water-permeable layer, so that the formation of pockmarks can be efficiently prevented. Can be done.

The fabric of the surface layer of the present invention is made of monofilaments with a flat cross section, and air bubbles and excess water are sent to the water permeable layer through the gaps, and are exhausted and drained to the outside through the water permeable layer. Then, when the excess water is drained, the amount of water necessary for curing the concrete is secured. In addition, the surface layer has a smooth surface, monofilaments are used, and there are no pores between the filaments, so it has excellent demoldability and can be used repeatedly without damaging the fabric surface.

The fabric used for the surface layer of the present invention may be a monofilament with a flat cross section, or a monofilament with a circular cross section may be woven and then flattened by heat and/or pressure. It's fine if you did it.

[0015] The latter case is more preferable from the viewpoint of manufacturing, since not only can the cross-sectional shape of the monofilaments be flattened, but also the monofilaments can be fused at their intersections.

[0016] The flatness, which is the percentage of the short axis to the long axis of the cross section of the monofilament of the present invention, is preferably 25 to 80%. If the flatness ratio is greater than 80%, as in the case of using monofilament with a circular cross section, the aperture ratio will be large and the fine powder of concrete milk will easily come out.
The density of the surface is impaired. On the other hand, if the aspect ratio is less than 25%, demoldability and durability during repeated use will be poor.

The monofilament constituting the fabric may be composed of one component or two or more components. In the former case, synthetic fibers such as polyester fibers, polyamide fibers, acrylic fibers, polyethylene fibers, and polypropylene fibers can be used.

In the latter case, if a core-sheath type composite fiber is used, the cross section can be made flat by melting only the sheath component, and since the core component is not melted, there is no decrease in strength. , preferably used. This combination of core and sheath components is suitable as long as the melting point of the sheath component is lower, and the core/sheath components are 6 nylon/polyethylene, polypropylene/polyethylene, polypropylene/ethylene-vinyl acetate copolymer, polyester/polypropylene, polyester/polyethylene. , 6 nylon/66 nylon, high melting point polyester/low melting point polyester, high density polyethylene/low density polyethylene, and the like. Note that the core component may be concentric with the sheath component or eccentric in the cross section of the monofilament.

[0019] The fineness of this monofilament is 50 to 25.
Preferably, it has a denier of 0. If the fineness is less than 50 denier, the fiber is not strong enough to be easily cut or scratched, resulting in fluffing and a change in the opening. vice versa,
If it exceeds 250 denier, it becomes difficult to obtain a gap that adequately excludes air bubbles and excess water.

[0020] The woven fabric made of monofilaments may be of any weaving method, and examples include plain weave, twill weave, and satin weave. Among these, plain weave is preferably used because gaps can be formed uniformly throughout the fabric.

The fabric is fused at the intersections of the monofilaments by heat and/or pressure. This fusion imparts dimensional stability to the fabric, prevents opening of the fabric during demolding or washing, and can suppress the occurrence of pockmarks.

[0022] The porosity, which is the percentage of the area occupied by the gaps in the fabric relative to the area of the entire fabric, is preferably 5 to 20%, and if it is less than 5%, air bubbles and excess water can be smoothly removed. If it exceeds 20%, it will not be possible to secure the amount of water necessary for hardening the concrete.

[0023] Also, the number of gaps per cm2 is 500
It is preferable that the number is ~2,000, and if it is less than 500, bubbles and excess water cannot be removed smoothly, and if it is 2,000 or more, the amount of water necessary for hardening the concrete is secured. become unable.

The permeable layer of the present invention excludes air bubbles and excess water. Examples of this water-permeable layer include nonwoven fabrics, woven fabrics, and knitted fabrics, but there is no particular limitation.

The fibers used in this water-permeable layer are preferably hydrophobic polyester fibers, polyolefin fibers, etc., but hydrophilic fibers may also be used. Further, the fiber may be made of one component, or it may be a composite fiber made of two or more components.

[0026] Any of the fibers can be of the same composition as the monofilament used for the surface layer fabric, but in the case of one-component fiber, in addition to the synthetic fibers that can be used for the monofilament, cotton, linen, Natural fibers such as silk and wool, and recycled fibers such as rayon can also be used. On the other hand, in the case of fibers consisting of two or more components, there are not only core-sheath composite fibers, but also sea-island fibers in which core components are arranged in a multi-core manner, side-by-side fibers in which the fibers are joined in cross section, or chemically or mechanically processed fibers. Easily splittable fibers that can be split by physical treatment can also be used.

Furthermore, by bonding the surface layer and the water-permeable layer and forming an adhesive layer between the surface layer and the water-permeable layer, the surface layer can be reinforced with the water-permeable layer. Changes in the mesh opening of the layered fabric become more difficult to occur,
More preferred.

This adhesive layer may be formed by the fusibility of the monofilaments constituting the surface layer fabric, or by the fusibility of the fibers constituting the water-permeable layer, or by interposing an adhesive resin. It may also be formed by combining these.

Adhesive resins that can be used in the present invention include polyvinyl butyral resins, vinyl chloride copolymer resins, vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, acrylate copolymer resins, and terephthalate resins. Acid-isophthalic acid copolymerized polyester resin, or polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-
Acrylic ester copolymer, aromatic copolyester,
Examples include hot melt adhesives such as co-condensed polyamide and polyurethane.

[0030] In order to bond the surface layer and the water-permeable layer, if adhesive fibers are used for the woven fabric and/or the non-woven fabric, woven fabric, knitted fabric, etc. constituting the water-permeable layer, after lamination, heat and A sheet for pasting a formwork can be obtained by applying pressure/or pressure. Furthermore, even if none of the nonwoven fabrics, textiles, knitted fabrics, etc. constituting the fabric and/or the water-permeable layer have adhesive properties, a sheet for attaching formwork can be obtained by interposing the adhesive resin as described above. . In addition, when obtaining a formwork sheet by applying heat and/or pressure as in the former case, the monofilaments constituting the fabric can be crushed at the same time as bonding, making the cross section flat, and the intersections of the monofilaments can be flattened. Since it can be fused, a sheet for pasting formwork can be easily obtained.

The formwork pasting sheet of the present invention is composed of the above-mentioned surface layer and a water-permeable layer, and the water-permeable layer is attached to the formwork side by adhesive or mechanical means on the inner surface of the formwork before it is installed. It is used by placing it so that the surface layer is in contact with the concrete.

[0032] Examples of the present invention will be described below, but the present invention is not limited to the following examples. Note that the flatness, porosity, and number of gaps per cm2 shown in Examples are values obtained based on electron micrographs.

[0033]

【Example】

(Example 1) The cross section is circular and the core component is polypropylene (
melting point 170℃), and the sheath component is polyethylene (melting point 130℃).
A core-sheath type composite monofilament with a fineness of 100 denier, in which the core component is arranged concentrically with respect to the sheath component, is used. A plain woven fabric with a diameter of 0.25 mm was obtained.

Next, this plain woven fabric was heat-treated at a temperature of 150° C. for 5 minutes to obtain a flat cross-sectional shape with a fabric weight of 75 g/m2 and a thickness of 0.16 mm, which was fused at the intersections of the monofilaments with polyethylene as a sheath component. A plain woven fabric was obtained. The flatness of this plain woven monofilament with a flat cross-sectional shape was 38%, the porosity was 10%, and the number of gaps per 1 cm2 was 1024.

On the other hand, polyester (fineness 3 denier) 6
After forming a fiber web using a carding method using 0% by weight and 40% by weight of rayon (3 denier), the fibers were bonded using an acrylic emulsion adhesive to obtain a fabric weight of 10%.
A nonwoven fabric having a weight of 0 g/m2 and a thickness of 0.5 mm was obtained.

[0036] The nonwoven fabric and plain fabric with a flat cross-sectional shape thus obtained were laminated in order on water-resistant plywood, placed so that the plain fabric was in contact with concrete, and then fixed with a stapler to obtain a formwork. Ta.

(Example 2) The core component is polypropylene,
Fabric weight 3 obtained by carding method using 80% by weight of composite fiber (3 denier fineness) whose sheath component is polyethylene and 20% by weight polyester fiber (3 denier fineness)
A fiber web of 0g/m2 (referred to as A fiber web), 80% by weight of polyester fiber (6 denier fineness), 20% by weight composite fiber (6 denier fineness) whose core component is polypropylene and whose sheath component is polyethylene is used. A fiber web (referred to as B fiber web) having a basis weight of 70 g/m 2 obtained by the card method was laminated.

[0038] After laminating the same plain fabric as in Example 1 on the A fiber web side, the temperature was 150°C and the pressure was 2kg/cm.
A heating and pressure treatment was performed in Step 2 to obtain a fused and integrated formwork attachment sheet.

[0039] The thus obtained formwork pasting sheet was laminated so that the B fiber web side was in contact with the water-resistant plywood, and then fixed with a stapler to obtain a formwork.

(Example 3) The cross section is circular, the core component is made of high melting point polyester (melting point 255°C), and the sheath component is made of low melting point polyester (melting point 200°C), and the core component is concentric with the sheath component. A core-sheath type composite monofilament with a fineness of 150 denier is used, and the weave density is 80 fibers/inch in both the length and width, the fabric weight is 110 g/m2, and the thickness is 0.3.
A plain woven fabric of mm was obtained.

Next, this plain woven fabric was subjected to heat and pressure treatment at a temperature of 200° C. and a pressure of 3 kg/cm2 to obtain a fabric with a fabric weight of 110 g/m2 and a thickness of 0, in which the low melting point polyester as a sheath component was fused at the intersections of the monofilaments. A plain woven fabric with a flat cross-sectional shape of .15 mm was obtained. This plain woven monofilament with a flat cross-sectional shape had an oblateness of 35%, a porosity of 10%, and the number of gaps per 1 cm2 was 1024.

[0042] Then, the same nonwoven fabric as in Example 1, a flat woven fabric with a flat cross-sectional shape, was laminated in order on water-resistant plywood, and after placing it so that the plain woven fabric was in contact with the concrete, it was fixed with a stapler to obtain a formwork. Ta.

(Comparative Example) A multifilament consisting of 30 polyester filaments (5 denier) was used, the weaving density was 80 filaments/inch in both length and width, and the fabric weight was 10.
A plain woven fabric having a weight of 5 g/m2 and a thickness of 0.3 mm was obtained. The porosity of this plain fabric is 15%, and the number of gaps per 1 cm2 is 1.
There were 024 pieces.

[0044] Then, the same nonwoven fabric and plain woven fabric as in Example 1 were laminated in order on water-resistant plywood, the plain woven fabric was placed in contact with concrete, and then fixed with a stapler to obtain a formwork.

(Repetitive Usability Test) The formwork obtained in Examples 1 to 3 and Comparative Example was
After assembling to a height of 1,800 mm, concrete was poured and cast, and after 4 days, the formwork was removed and the demoldability and pock rate were measured.

After that, the surface layer of the demolded formwork was washed with water and scrubbed with a brush, the formwork was assembled, concrete was poured, and the mold was demolded after 4 days, which were repeated to improve demoldability and pockmarking. The change in rate was measured. The results are shown in Table 1
Shown below.

[Table 1]

[0047] The demolding property was judged based on the following criteria. Excellent: When demolding, there is no concrete milk attached and there are no cuts or scratches on the monofilament surface. Good: When demolding, there is some concrete milk adhesion, and there are some cuts or scratches on the monofilament surface. Not acceptable: When demolding, there is a lot of concrete milk adhering, and the monofilament surface is cut or scratched.

The pock rate is determined by observing the concrete surface using an image processing device and using the following formula.

As can be seen from Table 1, the molds of Examples 1 to 3 are excellent in demoldability and pock rate even after repeated use, and can be used repeatedly without problems.

On the other hand, it can be seen that the mold of the comparative example had poor demoldability and poor pock rate, making it difficult to use repeatedly. In addition, it was observed that the formwork of the comparative example became fluffed when removed from the mold, and that the opening of the weave structure changed with each repeated use.

[0051]

Effects of the Invention: The fabric of the surface layer of the sheet for pasting formwork of the present invention is made of monofilaments with a flat cross section, so it has excellent demoldability and does not require careful cleaning. It will not be cut or scratched, the surface layer will not become fluffy, and the opening of the mesh will not change easily.
It does not cause pockmarks and can be used repeatedly without any problems.

Moreover, since the surface layer fabric is fused at the intersections of the monofilaments, the surface layer has excellent dimensional stability, and the mesh opening of the surface layer fabric is less likely to change, making it more pockable. The occurrence of can be suppressed.

[0053] In addition, the formwork pasting sheet of the present invention separates air bubbles and water using the surface layer, and transports and removes air bubbles and water using the water-permeable layer, so that the formation of pockmarks can be efficiently prevented. Can be done.

Claims (1)

[Claims] Claim 1: At least a permeable layer that excludes water;
1. A formwork pasting sheet comprising a surface layer made of a woven fabric in which intersections of monofilaments having flat cross sections are fused.