JP2004156226A - Form - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To overcome the problems that a conventional form causes many voids to remain in a concrete surface because redundant water and air in concrete are hard to remove, imposes a heavy burden on a worker due to the possession of relatively great weight, and causes the peeling of a finishing paint, the slip-off of a tile and the like. <P>SOLUTION: A form 10 is constituted in such a manner that a plate-like sheet B13 is arranged between a first sheet A11 and a second sheet A12. More specifically, the form 10 has a structure wherein the sheets A11 and A12 each are constituted on the backside the front and back sides of the sheet B13 in the direction of its thickness. In this case, the sheets A11 and A12 are permeable sheets which are composed of a polypropylene spunbonded nonwoven fabric, and the sheet B13 has a structure wherein a plurality of harmonica-shaped structures are stacked. This can bring about a long-life concrete hardened material having a compact surface with few voids and pinholes, caused by air bubbles. Additionally, the peeling of the finishing paint and the like can be prevented by virtue of lightness and the prevention of remanence of a release agent. <P>COPYRIGHT: (C)2004,JPO

Description

図４は本発明になる型枠の第１の実施の形態の斜視図を示す。同図において、型枠３０は、前述したハーモニカ状構造体（Ｐ−コア）の板状シート（シートＢ）３３の上下両面を、透水性シート（シートＡ）３１、３２で被覆した構造である。ここで、透水性シート（シートＡ）３１及び３２は、ポリプロピレンスパンボンド不織布のシートであり、ここでは前述したデュポン株式会社の登録商標名「タイパー」、あるいは「ザバーン」が用いられる。面材の条件としては、透水性、通気性を持ちセメント粒子や骨材等はしっかりと洩らさなくて、離型性、剛直性や耐アルカリ性に優れる機能を有することが好ましく、上記の登録商標名「タイパー」、あるいは「ザバーン」は、この機能を十分満たすものである。
【００３１】
また、板状シート（シートＢ）３３は、ここではダンプレート（ポリプロピレン製中空プレート）を同一方向に４段重ね合わせた構造である。勿論、ダンプレートの積み重ね段数は４段に限定されるものではなく、必要強度、コスト、作業性、生産性などを総合的に勘案して所望の高さ（厚さ）が得られるような段数とする。
【００３２】
また、板状シート（シートＢ）３３への透水性シート３１、３２の被覆方法は、図５に示すように板状シート（シートＢ）３３であるＰ−コアのＸＹ面に、透水性シート３１（３２）をタッカー又は熱シーラー、あるいは両面テープなどで貼り付ける方法が採られる。
【００３３】
次に、本発明の試験評価方法及び試験評価結果について説明する。本実施の形態の試験評価のために、コンクリート打設時と同様に、図６に示すように、平行に配置したセパレータ４１、４２の各両端を型枠固定具４３ａ及び４４ａ、４３ｂ及び４４ｂの内部の雌ネジ部に螺合させると共に、セパレータ４１、４２とは反対側から軸足４５ａ及び４６ａの各先端部を型枠固定具４３ａ及び４４ａの内部の雌ネジ部に螺合させ、かつ、軸足４５ｂ及び４６ｂの各先端部を型枠固定具４３ｂ及び４４ｂの内部の雌ネジ部に螺合させる。
【００３４】
ここで、一方の側の軸足４５ａ及び４５ｂが従来の型枠の一例としての合板ベニヤ４７の貫通孔に挿通されており、合板ベニヤ４７は単管パイプ４８ａ及び４８ｂと型枠固定具４３ａ及び４３ｂとにより狭持されて固定される。また、他方の側の軸足４６ａ及び４６ｂが、板状シート（シートＢ）５０の一面に透水性シート（シートＡ）５１が被覆された構造の本実施の形態の試験用型枠の貫通孔に挿通されており、この本実施の形態の試験用型枠は単管パイプ４９ａ及び４９ｂと型枠固定具４４ａ及び４４ｂとにより狭持されて固定される。
【００３５】
上記の板状シート５０及び透水性シート５１からなる試験用型枠は、ここでは透水性シート５１の目付け量が表２に示すように、１０５ｇ／ｍ^２であるもの（これを種類Ｓ−１とする）、１６５ｇ／ｍ^２であるもの（これを種類Ｓ−２とする）、１７５ｇ／ｍ^２であるもの（これを種類Ｓ−３とする）の計３種類であり、それぞれについて試験した。また、上記の合板ベニヤ４７と本実施の形態の試験用型枠のシートの取り付け方法と型枠サイズ（単位ｍｍ）は、表３に示すものを用いた。
【００３６】
【表２】

【表３】

次に、図６に示した合板ベニヤ４７と試験用型枠の透水性シート５１との間に、表４に示した強度及び組成のコンクリートを図６の紙面の上部から流し込み、バイブレーターで振動させながら均一に充填する。
【００３７】
【表４】

コンクリート打設後、２０時間養生した後に合板ベニヤ４７、板状シート５０及び透水性シート５１からなる試験用型枠、軸足４５ａ、４５ｂ、４６ａ及び４６ｂ、単管パイプ４８ａ、４８ｂ、４９ａ及び４９ｂを取り外した。このとき、合板ベニヤ４７は打設したコンクリート表面に張り付き取りにくかったが、本実施の形態の試験用型枠は打設したコンクリート表面から簡単に取り外れた。脱型後のコンクリート表面を観察すると、表５に示す結果が得られた。
【００３８】
【表５】

上記の試験結果から分るように、合板ベニヤを使用した側のコンクリート表面は、全体的にピンホールが多く、糖分もかなり付着していたが、種類Ｓ−２及びＳ−３の本実施の形態の試験用型枠を使用した場合は、コンクリート表面にピンホールは見られず、また色が均一であり、スムースでボイドの無い緻密な表面を持つコンクリート硬化物が得られた。
【００３９】
また、本発明の型枠は主構成要素である板状シートがハーモニカ構造であるため、コンクリート内の水分の十分な脱水量が得られると共に、型枠合板に比べて大幅な軽量化を実現でき、また、熱可塑性樹脂製の天板とクッション層が積層された構造の型枠に比べても軽量化を実現できる。
【００４０】
なお、透水性シート（シートＡ）３１、３２として、登録商標「タイパー」を使用した場合は、一般的には厚みは２５ｍｍ以下で、孔の大きさはセメントの粒子を外に流れ出さないために、０．０５ｍｍ以下であることが好ましい。また、板状シート（シートＢ）３３の重量は、１５〜２０ｍｍ厚みで約１〜２ｋｇ／ｍ^２であり、縦１８０ｃｍ×横６０ｃｍの通常サイズで重量約１３ｋｇ（約１２ｋｇ／ｍ^２）の従来の合板製型枠の十分の一という大幅な軽量化を実現できるため、本実施の形態の型枠は作業者の負担を軽減することに寄与する。
【００４１】
なお、本実施の形態では、板状シート（シートＢ）３３の両面に透水性シート（シートＡ）３１、３２を設けているため、実際のコンクリート打設毎に交互に、あるいは所定回数毎に透水性シート（シートＡ）３１側又は３２側がコンクリート表面に対向するように用い、透水性シート（シートＡ）３１、３２が古くなった時点で剥がして、新しい透水性シート（シートＡ）３１、３２を板状シート（シートＢ）３３に貼ることで、再び所期の効果を得ることができる。繰り返し使用の観点から、透水性シート（シートＡ）３１、３２は表面をポイント・ボンデイングしたシートがよい。
【００４２】
特に、透水性シート（シートＡ）３１、３２として登録商標「ザバ−ン」を使用した場合は、数回使用後新しい「ザバーン」に取り替えることにより、板状シート３３はさらに再使用でき、トータルの合理化が図れる。また、「ザバーン」と板状シート３３は同じポリプロピレン樹脂であるため、そのままリサイクルにまわすこともできる。
【００４３】
次に、本発明の第２の実施の形態について説明する。図７（Ａ）は本発明になる型枠の第２の実施の形態の斜視図、同図（Ｂ）は同図（Ａ）の部分拡大断面図を示す。同図中、図４と同一構成部分には同一符号を付してある。図７（Ａ）において、型枠６０は、前述したハーモニカ状構造体（Ｐ−コア）の板状シート（シートＢ）３３の上下両面だけでなく、前面と後面の計４面を、透水性シート（シートＡ）６１で覆った構造である。ここで、透水性シート（シートＡ）６１は、ポリプロピレンスパンボンド不織布のシートであり、ここでは前述したデュポン株式会社の登録商標名「タイパー」、あるいは「ザバーン」が用いられる。
【００４４】
ここで、板状シート（シートＢ）３３に対する透水性シート（シートＡ）６１の固定方法は、図７（Ａ）及び（Ｂ）に示すように、釘６２で固定する方法がとられる。釘６２としては、ナイロン釘、ポリプロピレン釘又は鉄釘が用いられる。なお、釘６２の替わりに、コ字状の留め材を用いることもできる。本実施の形態も第１の実施の形態と同様の効果を得ることができ、更に、透水性シート（シートＡ）６１をより強固に板状シート（シートＢ）３３に固定することができる。
【００４５】
次に、本発明の第３の実施の形態について説明する。図８は本発明になる型枠の第３の実施の形態の斜視図を示す。同図中、図７と同一構成部分には同一符号を付してある。この実施の形態の型枠７０は、図８に示すように、前述したハーモニカ状構造体（Ｐ−コア）の板状シート（シートＢ）３３の替わりに、多孔質樹脂板７１の上下面及び前後面の計４面を、透水性シート（シートＡ）６１で覆うと共に、釘６２で多孔質樹脂板７１に固定した構造である。
【００４６】
多孔質樹脂板７１は、ハーモニカ状構造体と同等の強度を有すると共に、透水性、通気性を持ちセメント粒子や骨材等は洩らさず、空気が抜ける穴が多数形成された構造であり、例えばプラスチックにより構成される。この実施の形態も、第１及び第２の実施の形態と同様の効果を有する。
【００４７】
なお、本発明は以上の実施の形態に限定されるものではなく、例えば図１及び図４では、板状シート（シートＢ）１３、３３の両面に透水性シート（シートＡ）１１、１２、３１、３２を設けていたが、どちらか一方のみであってもよい。また、所望の強度を得るために、シートＢ１３、３３にはリブを入れるなどしてもよい。
【００４８】
また、透水性シート（シートＡ）１１、１２、３１、３２を釘などで板状シート（シートＢ）１３、３３の両面に固定するようにしてもよく、更に、図１及び図４に示した板状シート（シートＢ）１３、３３の替わりに、図８の多孔質樹脂板を用いてもよい。また更に、板状シート（シートＢ）１３、３３あるいは多孔質樹脂板７１の全６面を透水性シート（シートＡ）で覆ってから釘等で固定してもよい。また、透水性シート（シートＡ）を用いず、図８の多孔質樹脂板のみを型枠として使用することも可能である。
【００４９】
【発明の効果】
以上説明したように、本発明によれば、コンクリート打設時に用いる型枠を、ハーモニカ構造の板状シートの上下両面の少なくとも一方の面に、ポリプロピレンスパンボンド不織布のシートを設けた構造としたため、従来の型枠に比べて以下の数々の特長を有するものである。
【００５０】
（１）気泡から引き起こされるボイドやピンホールが少なく、緻密な表面を持つ、長寿命のコンクリート硬化物が得られる。
【００５１】
（２）Ｗ／Ｃ（水とセメントとの比率）の適性比率から，セメント量が増加（約４０％程度）し、打設したコンクリートの表面から例えば約２５ｍｍまで緻密化ができる。
【００５２】
・海水などからの塩素化、炭酸ガスによるコンクリートの中和反応（２〜１０倍改良）
・凍結−融解からの崩壊（約１００倍）
・苔や海藻の付着やバクテリアの繁殖の防止
（３）コンクリート表面に離型剤が殆ど残らず、また、ベニヤ製型枠合板のような材木の油成分が全く存在しないため、仕上げ塗料の剥離やタイルの滑落を防止できる。
【００５３】
（４）主構成要素である板状シートがハーモニカ構造であるため、コンクリート内の水分の十分な脱水量が得られると共に、型枠合板に比べて大幅な軽量化を実現でき、また、熱可塑性樹脂製の天板とクッション層が積層された構造の型枠に比べても軽量化を実現でき、これにより作業者の重力に対する負担の軽減ができ、作業能率向上が図れる。
【００５４】
（５）表面の透水性シートがポリプロピレン樹脂で構成されているため、古くなった透水性シートを新しい透水性シートに貼り替えることで、型枠の長寿命化が図れると共に、古い透水性シートをリサイクルにまわすことができ、地球環境に優しい。
【００５５】
（６）木材及びその加工製品（紙など）を使用しないため、森林資源の枯渇と地球の温暖化の抑制ができる。
【００５６】
（７）透水性シートとして用いるポリプロピレンスパンボンド不織布の養生保護膜の機能で、コンクリート中の余剰水や空気の速やかな排出により、コンクリート硬化速度が、暑い気候や乾燥している気候に影響されない。
【図面の簡単な説明】
【図１】本発明の原理構成図である。
【図２】ハミカム構造の一例の説明図である。
【図３】本発明の要部のハーモニカ構造の説明図である。
【図４】本発明の第１の実施の形態の斜視図である。
【図５】本発明の第１の実施の形態における透水性シートの板状シートへの貼り付け説明図である。
【図６】本発明の試験評価方法に用いるコンクリート打設時の一例の構成図である。
【図７】本発明の第２の実施の形態の斜視図及び部分拡大断面図である。
【図８】本発明の第３の実施の形態の斜視図である。
【図９】従来のコンクリート打設方法の一例を示す図である。
【符号の説明】
１０、３０、６０、７０ 型枠
１１、１２ シートＡ
１３ シートＢ
３１、３２、５１、６１ 透水性シート（シートＡ）
３３、５０ 板状シート（シートＢ）
４１、４２ セパレータ
４３ａ、４３ｂ、４４ａ、４４ｂ 型枠固定具
４５ａ、４５ｂ、４６ａ、４６ｂ 軸足
４７ 合板ベニヤ
４８ａ、４８ｂ、４９ａ、４９ｂ 単管パイプ
６２ 釘
７１ 多孔質樹脂板[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a formwork, and more particularly, to a formwork used at the time of placing concrete.
[0002]
[Prior art]
In the conventional concrete casting method, as shown in FIG. 9, both ends of the separator 1 are screwed into female threads inside the mold fixtures 2 and 3, and the connection is made through the through holes of the mold 5 from outside. A shaft foot 7, which is a bolt, is screwed into the female screw portion inside the mold fixture 2 from the side opposite to the separator 1, and a form tie 4 penetrating through the shaft foot 7 is connected to the mold 5 with the mold fixture 2. After being clamped in between, it is firmly fixed with a pipe 8 and the formwork 5 is firmly supported. Similarly, the formwork 6 is firmly fixed to the formwork fixture 3 side. Then, concrete 9 is poured between the formwork 5 and the formwork 6.
[0003]
Thereafter, after the concrete 9 has hardened, the foam tie 4, the pipe 8, the shaft feet 7, and the molds 5 and 6 are removed. Thereby, the concrete 9 is cast and formed. Conventionally, molds 5 and 6 have been used as molds used for placing concrete. The molds 5 and 6 are made of plywood veneer or steel.
[0004]
By the way, in order to extend the life of concrete, it is necessary to prevent corrosion due to rust of reinforcing bars in recent years in which a highly durable building structure is required. In this case, external factors from the outer surface of the concrete, such as salt, oxygen, water, carbon dioxide, etc., enter the inside of the concrete, so that the neutralization of the concrete progresses and eventually causes corrosion of the reinforcing steel. It is believed that. Therefore, it is possible to prevent the attack of external factors and prolong the life of the concrete by how to increase the density of the outer surface layer of the concrete.
[0005]
However, when looking at concrete structures constructed using concrete casting methods that are currently in common use, many voids are generated on the surface of cast concrete due to air bubbles, and the surface condition is not always sufficient. Not. For this reason, it can be said that it is very susceptible to external factors. This is because it is difficult for surplus water, air and the like in the concrete 9 to escape from the molds 5 and 6.
[0006]
Therefore, a concrete form having water permeability is conventionally known (see Patent Document 1). In this conventional formwork, a sheet having water permeability is stretched on the top plate part of the thermoplastic resin concrete formwork without being adhered to the entire surface of the top plate part, and the end of the sheet is It is a structure that is joined on the outer peripheral side wall surface of the concrete formwork, thereby trying to remove excess moisture in the cast concrete.
[0007]
[Patent Document 1]
JP-A-8-053935 (page 27, right column, line 27-page 4, left column, line 33, FIG. 1 to FIG. 5)
[0008]
[Problems to be solved by the invention]
Considering the reusability of formwork, the problem of depletion of timber resources and the burden on workers due to the weight at the time of construction, etc., it is unavoidable to reduce the formwork weight and change from timber to other materials It is a problem. Also, in order to enhance the releasability of the concrete from the mold and the reusability of the mold, it is common to apply a release agent to the surface of the mold. It may cause the tile to slide down. Further, when the molds 5 and 6 are made of plywood veneer, it is also known that oily components of wood (for example, rosin) remain on the concrete surface and cause a problem of peeling.
[0009]
On the other hand, in the conventional mold having water permeability described in Patent Document 1, a sheet having water permeability is adhered to the entire top surface of the cushion layer via the cushion layer on the top plate portion of the concrete frame made of thermoplastic resin. The extra-water is absorbed by the cushion layer, which is an inorganic fiber sheet such as a glass fiber sheet. Since the sheet is permeable, a laminated structure of the cushion layer and the top plate is required on the sheet having water permeability, and there is a problem that the weight is heavy. There is a problem that the amount of dehydration of excess water is insufficient.
[0010]
The present invention has been made in view of the above points, and an object of the present invention is to provide a mold that is more environmentally friendly, more durable, and can be used at the time of efficient concrete placement than a mold.
[0011]
It is another object of the present invention to provide a formwork capable of obtaining a sufficient amount of dehydration and reducing the load on an operator by reducing the weight.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a formwork used during concrete casting, a plate-like sheet having a structure in which a plurality of harmonica-like structures are stacked in the same direction, and a front surface and a back surface in the thickness direction of the plate-like sheet. And a water-permeable sheet including a surface in contact with the concrete to be poured.
[0013]
Further, in order to achieve the above object, the present invention provides, in a formwork used during concrete casting, a plate-like sheet having a structure in which a plurality of harmonica-like structures are stacked in the same direction, and a thickness direction of the plate-like sheet. The structure has a water-permeable sheet provided so as to cover the front surface, the back surface, the front surface, and the rear surface, respectively, and including a surface in contact with the concrete to be poured.
[0014]
Here, the plate-like sheet is a harmonica-like structure, has water permeability (air permeability) and lightness, like the honeycomb-like structure, and is more versatile than the honeycomb-like structure in each direction. And high strength. The water-permeable sheet has at least water permeability, but retains cement particles, aggregates, and the like, and is characterized by having high rigidity with respect to a certain pressure.
[0015]
Here, the above-mentioned water-permeable sheet is detachably attached to a plate-like sheet before or after placing concrete with a tacking material such as a tucker, a heat sealer, a double-sided tape, or a nail. And According to the present invention, the water permeable sheet can be replaced with a new one before placing concrete.
[0016]
In the present invention, the water-permeable sheet has a structure made of a polypropylene spunbonded nonwoven fabric. In the present invention, the water-permeable sheet is (1) permeable to water, but retains cement particles and aggregates, (2) is hardly hydrolyzed by alkalinity, and (3) is subjected to pressure during construction. High rigidity so that it does not deform, and (4) dimensional stability and easy release from the cement surface, (5) light weight, workability (cutting, etc.), cost, disposability / It can be configured to have recyclability. Further, in the present invention, instead of the plate-like sheet, a porous resin plate which does not leak cement particles and allows air to escape can be used.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a principle configuration diagram of a mold according to the present invention. As shown in the drawing, the mold 10 has a configuration in which a plate-like sheet B13 is disposed between a first sheet A11 and a second sheet A12. That is, the mold 10 has a structure in which the sheets A11 and A12 are respectively formed on the front surface and the back surface of the plate-shaped sheet B13 in the thickness direction. Here, the sheets A11 and A12 are water-permeable sheets, and the sheet B13 has a structure in which a plurality of harmonica-like structures are stacked. At the time of concrete placement, one of the sheets A11 and A12 comes into contact with the poured concrete.
[0018]
Next, the sheets A and B will be described in more detail. In order to make the concrete surface dense, it is necessary to allow excess water and air to escape smoothly when pouring concrete, and to hold cement particles and aggregates firmly. As such a material, a sheet such as a spunbonded nonwoven fabric made of polypropylene (for example, a registered trademark “Typer” or “Zaburn” of DuPont Co., Ltd.) that is strong in alkalinity and easily leaks water or air is used as a sheet. Desirable as A.
[0019]
As an alternative to the currently used formwork, various companies have proposed plastics reinforced with glass fiber. Although this type of formwork is effective to some extent in terms of weight reduction, its finish is far from a satisfactory fine finish due to the structure in which an escape route such as water or air is not secured. In order to solve this, it is desirable that the sheet B has the same strength as the plywood and can secure a passage for water or air from the surface. By combining the sheets A and B having the above characteristics, it is possible to realize a formwork capable of producing a high-performance concrete structure.
[0020]
To summarize the above, as the sheet A (11 and 12), various sheets including a woven fabric and a nonwoven fabric can be considered, but the following conditions must be satisfied.
[0021]
(1) Although it has water permeability, it retains cement particles and aggregates.
[0022]
{Circle around (2)} Hardly hydrolyzed by alkalinity.
[0023]
(3) It has high rigidity so that it is not deformed by pressure during construction.
[0024]
(4) It has dimensional stability and easy release from the cement surface.
[0025]
(5) Light weight, workability (cutting, etc.), cost, disposal / recyclability, etc.
[0026]
In consideration of the above points, the sheet A (11 and 12) is most preferably a sheet of polypropylene spunbond nonwoven fabric, which is called DuPont Co., Ltd. registered trade name "Typer" or registered trade name "Zaburn". However, as long as the above conditions are satisfied, it is needless to say that the present invention is not limited to this.
[0027]
Next, the structure of the plate-like sheet B (13) will be described in more detail. Structures having a honeycomb structure shown in FIG. 2 and a harmonica structure shown in FIG. 3A are known. In the honeycomb structure of FIG. 2, the honeycomb surface 15 has high pressure resistance, but the surface 16 in the width direction (W direction) orthogonal to the honeycomb surface 15 and the surface in the length direction (L direction) have low pressure resistance. Also, paper is cheap as a material, but cannot be used as a formwork for concrete casting, so that a material other than paper must be used, which is expensive.
[0028]
On the other hand, the harmonica structure shown in FIG. 3A has a higher pressure resistance on each surface than the honeycomb structure, and thus is preferable as the plate-like sheet B (13). As the harmonica structure, for example, there is a P-core made of a polypropylene dam plate manufactured by Ube Nitto Kasei Co., Ltd. The combination of the dam plates and the thickness are determined in consideration of the required strength, cost, workability and productivity.
[0029]
Here, the P-core is a harmonica-shaped structure obtained by stacking a number of dam plates (hollow plates made of polypropylene) shown in FIG. 3B in the same direction and cutting them while heat-sealing them with a hot nichrome wire. It is. The porosity and weight of the P-core can be changed depending on the type of the dam plate used, and the pressure resistance of the XY surface 20 in FIG. 3 can also be adjusted. However, as shown in Table 1, the pressure resistance of the YZ plane 21 and the ZX plane 22 is lower than the XY plane 20. Since a concrete form requires a pressure resistance of about 20 kg / m ^{2, it} is necessary to reinforce some of these surfaces.
[0030]
[Table 1]

FIG. 4 shows a perspective view of the first embodiment of the mold according to the present invention. In the figure, a mold 30 has a structure in which the upper and lower surfaces of a plate-like sheet (sheet B) 33 of the above-described harmonica-like structure (P-core) are covered with water-permeable sheets (sheets A) 31 and 32. . Here, the water-permeable sheets (sheets A) 31 and 32 are sheets of polypropylene spunbonded nonwoven fabric, and the registered trade name "Typer" or "Zaburn" of DuPont is used here. As the condition of the face material, it is preferable that the material has water permeability, air permeability, does not leak cement particles and aggregates firmly, and has a function of excellent releasability, rigidity and alkali resistance. The brand name "Typer" or "Zaburn" satisfies this function sufficiently.
[0031]
In addition, the plate-like sheet (sheet B) 33 has a structure in which dam plates (hollow plates made of polypropylene) are stacked in four steps in the same direction. Of course, the number of stacking stages of the dam plate is not limited to four, and the number of stages that can obtain a desired height (thickness) in consideration of necessary strength, cost, workability, productivity, and the like comprehensively. And
[0032]
In addition, as shown in FIG. 5, a method of coating the sheet-like sheet (sheet B) 33 with the water-permeable sheets 31 and 32 is as follows. A method of attaching 31 (32) with a tucker, a heat sealer, or a double-sided tape is used.
[0033]
Next, the test evaluation method and test evaluation results of the present invention will be described. For the test evaluation of the present embodiment, as in the case of concrete casting, as shown in FIG. 6, both ends of the separators 41 and 42 arranged in parallel are connected to the form fixtures 43a and 44a, 43b and 44b. While being screwed into the internal female screw portion, the distal ends of the shaft feet 45a and 46a are screwed into the female screw portions inside the formwork fixing tools 43a and 44a from the side opposite to the separators 41 and 42, and The distal ends of the shaft feet 45b and 46b are screwed into female screw portions inside the form fixing tools 43b and 44b.
[0034]
Here, the shaft feet 45a and 45b on one side are inserted into through holes of a plywood veneer 47 as an example of a conventional formwork, and the plywood veneer 47 is connected to the single pipes 48a and 48b and the formwork fixtures 43a and 43b. 43b. In addition, the shaft feet 46a and 46b on the other side have through-holes in the test form of this embodiment having a structure in which a plate-like sheet (sheet B) 50 is covered with a water-permeable sheet (sheet A) 51 on one surface. The test formwork of the present embodiment is clamped and fixed by the single pipes 49a and 49b and the formwork fixtures 44a and 44b.
[0035]
As shown in Table 2, the test mold composed of the plate-like sheet 50 and the water-permeable sheet 51 has a basis weight of 105 g / m ^{2 as} shown in Table 2 (this is a type S-1). 165 g / m ² (this is referred to as type S-2), and 175 g / m ² (this is referred to as type S-3), and each was tested. . Table 3 shows the method of attaching the plywood veneer 47 and the sheet of the test formwork of the present embodiment and the formwork size (unit: mm).
[0036]
[Table 2]

[Table 3]

Next, between the plywood veneer 47 shown in FIG. 6 and the water-permeable sheet 51 of the test form, concrete having the strength and composition shown in Table 4 was poured from the top of the paper of FIG. 6 and vibrated by a vibrator. While filling.
[0037]
[Table 4]

After the concrete is cast and cured for 20 hours, a plywood veneer 47, a test formwork composed of a plate-like sheet 50 and a water-permeable sheet 51, shaft feet 45a, 45b, 46a and 46b, single pipes 48a, 48b, 49a and 49b. Was removed. At this time, the plywood veneer 47 was difficult to stick to the cast concrete surface, but the test form of the present embodiment was easily removed from the cast concrete surface. Observation of the concrete surface after demolding gave the results shown in Table 5.
[0038]
[Table 5]

As can be seen from the above test results, the concrete surface on the side using the plywood veneer had many pinholes and a large amount of sugars on the whole, but the types S-2 and S-3 of the present embodiment were used. When the test form of the embodiment was used, no pinholes were observed on the concrete surface, and a cured concrete product having a uniform color, a smooth surface and a dense surface without voids was obtained.
[0039]
In addition, since the form sheet of the present invention has a harmonica structure in the plate-like sheet as a main component, a sufficient amount of dehydration of water in concrete can be obtained, and the weight can be significantly reduced as compared with the formwork plywood. Further, the weight can be reduced as compared with a mold having a structure in which a top plate made of a thermoplastic resin and a cushion layer are laminated.
[0040]
In addition, when the registered trademark "Tiper" is used as the water permeable sheets (sheets A) 31 and 32, the thickness is generally 25 mm or less, and the size of the holes does not allow the cement particles to flow out. Preferably, it is 0.05 mm or less. Further, the weight of the plate-shaped sheet (sheet B) 33 is about 1-2 kg / m ² at a thickness of 15 to 20 mm, and about 13 kg (about 12 kg / m ² ) in a normal size of 180 cm × 60 cm. Therefore, the formwork of the present embodiment contributes to reducing the burden on the worker.
[0041]
In the present embodiment, since the water-permeable sheets (sheets A) 31 and 32 are provided on both sides of the plate-like sheet (sheet B) 33, the sheets are alternately formed every time concrete is cast or every predetermined number of times. The water-permeable sheet (sheet A) 31 or 32 is used such that the side of the water-permeable sheet (sheet A) 31 or 32 faces the concrete surface. The desired effect can be obtained again by sticking 32 on the plate-like sheet (sheet B) 33. From the viewpoint of repeated use, the water-permeable sheets (sheets A) 31 and 32 are preferably sheets whose surfaces are point-bonded.
[0042]
In particular, when the registered trademark "Zabern" is used as the water permeable sheets (sheets A) 31 and 32, the plate-shaped sheet 33 can be reused further by replacing it with a new "Zabarn" after several uses, and Can be streamlined. Further, since "Zabarn" and the plate-like sheet 33 are made of the same polypropylene resin, they can be recycled as they are.
[0043]
Next, a second embodiment of the present invention will be described. FIG. 7A is a perspective view of a second embodiment of a mold according to the present invention, and FIG. 7B is a partially enlarged sectional view of FIG. 7A. 4, the same components as those in FIG. 4 are denoted by the same reference numerals. In FIG. 7 (A), the mold 60 is made of not only the upper and lower surfaces of the above-mentioned plate-like sheet (sheet B) 33 of the harmonica-like structure (P-core) but also a front surface and a rear surface of a total of four surfaces. This is a structure covered with a sheet (sheet A) 61. Here, the water-permeable sheet (sheet A) 61 is a sheet of polypropylene spun-bonded nonwoven fabric, and here, the above-mentioned registered trademark "Typer" or "Zaburn" of DuPont is used.
[0044]
Here, as a method of fixing the water-permeable sheet (sheet A) 61 to the plate-like sheet (sheet B) 33, a method of fixing with a nail 62 as shown in FIGS. As the nail 62, a nylon nail, a polypropylene nail, or an iron nail is used. Instead of the nail 62, a U-shaped fastening member can be used. In this embodiment, the same effect as in the first embodiment can be obtained, and the water-permeable sheet (sheet A) 61 can be more firmly fixed to the plate-like sheet (sheet B) 33.
[0045]
Next, a third embodiment of the present invention will be described. FIG. 8 shows a perspective view of a third embodiment of the formwork according to the present invention. 7, the same components as those in FIG. 7 are denoted by the same reference numerals. As shown in FIG. 8, the mold 70 of this embodiment includes upper and lower surfaces of a porous resin plate 71 instead of the above-described plate-like sheet (sheet B) 33 of the harmonica-like structure (P-core). In this structure, a total of four front and rear surfaces are covered with a water-permeable sheet (sheet A) 61 and fixed to a porous resin plate 71 with nails 62.
[0046]
The porous resin plate 71 has the same strength as the harmonica-like structure, has water permeability, air permeability, does not leak cement particles and aggregates, and has a structure in which many holes through which air escapes are formed. , For example, made of plastic. This embodiment also has the same effect as the first and second embodiments.
[0047]
The present invention is not limited to the above embodiment. For example, in FIGS. 1 and 4, water-permeable sheets (sheets A) 11 and 12 are provided on both sides of plate-like sheets (sheets B) 13 and 33. Although 31 and 32 are provided, only one of them may be provided. In order to obtain a desired strength, the sheets B13 and 33 may be provided with ribs.
[0048]
Further, the water-permeable sheets (sheets A) 11, 12, 31, 32 may be fixed to both sides of the plate-like sheets (sheets B) 13, 33 with nails or the like, and further shown in FIGS. Instead of the plate-shaped sheets (sheets B) 13 and 33, a porous resin plate shown in FIG. 8 may be used. Further, all six surfaces of the plate-like sheets (sheets B) 13 and 33 or the porous resin plate 71 may be covered with a water-permeable sheet (sheet A) and then fixed with nails or the like. Further, it is also possible to use only the porous resin plate of FIG. 8 as a mold without using the water-permeable sheet (sheet A).
[0049]
【The invention's effect】
As described above, according to the present invention, the form used during concrete casting has a structure in which a sheet of polypropylene spunbonded nonwoven fabric is provided on at least one of the upper and lower surfaces of the harmonica-structured plate-like sheet. It has the following many features as compared to the conventional mold.
[0050]
(1) A long-life hardened concrete having a dense surface with few voids and pinholes caused by air bubbles can be obtained.
[0051]
(2) From the appropriate ratio of W / C (the ratio of water to cement), the amount of cement is increased (about 40%), and the concrete can be densified from the surface of the poured concrete to, for example, about 25 mm.
[0052]
・ Chlorination from seawater, neutralization reaction of concrete with carbon dioxide (2-10 times improvement)
・ Disintegration from freeze-thaw (about 100 times)
・ Prevention of adhesion of moss and seaweed and propagation of bacteria (3) Since there is almost no mold release agent on the concrete surface and no oil component of timber such as veneer formwork plywood, peeling of finish paint And sliding of tiles can be prevented.
[0053]
(4) Since the plate-like sheet, which is a main component, has a harmonica structure, a sufficient amount of water in the concrete can be obtained, and the weight can be significantly reduced as compared with the formwork plywood. The weight can be reduced as compared with a mold having a structure in which a resin-made top plate and a cushion layer are laminated, whereby the burden on an operator can be reduced, and work efficiency can be improved.
[0054]
(5) Since the water-permeable sheet on the surface is made of polypropylene resin, by replacing the old water-permeable sheet with a new water-permeable sheet, the life of the mold can be extended and the old water-permeable sheet can be used. It can be recycled and is environmentally friendly.
[0055]
(6) Since wood and processed products (such as paper) are not used, depletion of forest resources and suppression of global warming can be achieved.
[0056]
(7) The function of the protective film of the polypropylene spunbond nonwoven fabric used as the water-permeable sheet, and the rapid discharge of surplus water and air in the concrete allows the concrete hardening rate to be unaffected by hot or dry climates.
[Brief description of the drawings]
FIG. 1 is a principle configuration diagram of the present invention.
FIG. 2 is an explanatory diagram of an example of a honeycomb structure.
FIG. 3 is an explanatory diagram of a harmonica structure of a main part of the present invention.
FIG. 4 is a perspective view of the first embodiment of the present invention.
FIG. 5 is an explanatory diagram of attaching a water-permeable sheet to a plate-like sheet according to the first embodiment of the present invention.
FIG. 6 is a configuration diagram of an example at the time of placing concrete used in the test evaluation method of the present invention.
FIG. 7 is a perspective view and a partially enlarged cross-sectional view of a second embodiment of the present invention.
FIG. 8 is a perspective view of a third embodiment of the present invention.
FIG. 9 is a diagram showing an example of a conventional concrete placing method.
[Explanation of symbols]
10, 30, 60, 70 Formwork 11, 12 Sheet A
13 Sheet B
31, 32, 51, 61 Water-permeable sheet (sheet A)
33, 50 Plate sheet (sheet B)
41, 42 Separator 43a, 43b, 44a, 44b Formwork fixing device 45a, 45b, 46a, 46b Shaft leg 47 Plywood veneer 48a, 48b, 49a, 49b Single tube pipe 62 Nail 71 Porous resin plate

Claims (5)

In the formwork used when casting concrete,
A plate-like sheet having a structure in which a plurality of harmonica-like structures are stacked in the same direction,
A formwork comprising: a water-permeable sheet provided on at least one of the front surface and the back surface in the thickness direction of the plate-shaped sheet, and including a surface in contact with concrete to be cast. In the formwork used when casting concrete,
A plate-like sheet having a structure in which a plurality of harmonica-like structures are stacked in the same direction,
A formwork comprising: a water-permeable sheet that is provided so as to cover the front surface, the back surface, the front surface, and the rear surface in the thickness direction of the plate-shaped sheet, respectively, and includes a surface in contact with concrete to be cast. The water-permeable sheet is detachably attached to the plate-like sheet before or after concrete casting with a fastening member such as a tucker, a heat sealer, a double-sided tape, or a nail. Item 3. The mold according to Item 1 or 2. The mold according to any one of claims 1 to 3, wherein the water-permeable sheet is made of a polypropylene spunbonded nonwoven fabric. The mold according to any one of claims 1 to 4, wherein a porous resin plate that does not leak cement particles and allows air to escape is used in place of the plate-like sheet.

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