JPH0610429A - Hydraulic inorganic permanent form - Google Patents

Abstract

PURPOSE:To firmly join the body and mortar layer of a concrete structure. CONSTITUTION:Concrete is casted using a hydraulic, inorganic permanent form having dovetail grooves 3 or dovetail mortises provided on its finished surface side or both its concrete casted surface side and finished surface side, and mortar is applied to the finished surface without stripping the concrete. Part of the mortar or concrete is poured into the dovetail grooves 3 and hardened so that a body 1 and the mortar layer 4 are firmly joined together.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork and a method for producing the formwork, and a concrete structure using the formwork, in a concrete structure for construction or civil engineering, which can maintain good joint between a skeleton and a finishing material. Regarding the construction method of the object.

[0002]

2. Description of the Related Art In general, the surface of a concrete structure for construction or civil engineering is constructed by pouring concrete using a formwork to construct a skeleton, and after demolding, to finish the surface of the skeleton,
Mortar is applied, and the surface is tiled and spray coated. In the concrete structure thus constructed, there has been a problem that the skeleton and the mortar layer, which is a finishing material, are peeled off and lifted up, and the finished surface is peeled off. Therefore, in order to solve this problem, Japanese Patent Laid-Open No. 58-101960 discloses a surface treatment method for a concrete skeleton in which a porous fiber sheet is interposed at the joint surface between the concrete skeleton surface and the mortar layer. JP-A-156857 discloses a method of applying a polymer cement-based adhesive to the surface of a concrete skeleton, attaching a porous fiber sheet, and applying a finishing surface,
Japanese Patent Laid-Open No. 4-52365 discloses, as a symptomatic treatment for preventing peeling of the finished surface, a mesh sheet made of a fiber material is covered on the finished surface and fixed with an anchor, and polymer cement is applied to the surface to prevent the outer wall from peeling off. A method has been proposed.

[0003]

However, these proposals have problems that the fiber material used and the mortar are not joined sufficiently, the construction is complicated, and the cost tends to increase. The present invention improves the joint between the concrete skeleton and the mortar layer to make it strong,
Formwork that can be rationalized and its manufacturing method,
It was completed with the object of providing a safe construction method for concrete structures using the formwork.

[0004]

As a means for solving the above problems, the present invention provides a permanent set of hydraulic inorganic material having a dovetail groove or a dovetail hole on the finished surface side, and
Provided are two types of permanent molds, a hydraulic inorganic permanent mold having a groove or a hole provided on the concrete pouring surface side and the finishing surface side. These hydraulic inorganic material-based permanent molds are preferably produced by extruding a mixture of a hydraulic inorganic material, a reinforcing material, an extrusion aid and water, and then curing the molded product. Furthermore, in the construction of concrete structures, concrete is placed using the above-mentioned permanent formwork to build a skeleton, and mortar construction is applied to the finished surface side of the permanent formwork without demolding, and the finished surface is applied. Characterized by
A method for constructing a concrete structure is provided.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described with reference to the drawings showing the embodiments. FIG. 1 is a cross-sectional view of a main part of a concrete structure constructed by using a hydraulic inorganic permanent mold having a groove or a hole on the concrete placing surface side and the finishing surface side of the present invention. .

The formwork 2 of the present invention is used for placing concrete as the skeleton 1, but it is a permanent formwork made of a hydraulic inorganic substance and is used after placing concrete. Even if it is not removed, it is firmly joined to the cast concrete (frame 1) and integrated to form the surface portion of the frame 1. Further, this formwork 2 has a finishing surface side,
Alternatively, it is characterized in that the dovetail groove 3 or the dovetail hole is provided on the concrete placing surface side and the finishing surface side.

The hydraulic inorganic material, which is the main constituent material of the mold 2, is usually a calcareous inorganic material and a silicic acid inorganic material as the main raw materials, to which a reinforcing material or the like is added according to the purpose. The additives are not limited to inorganic substances, and organic fibers and thickeners can be added. As the calcareous raw material, for example, plain cement such as Portland cement or alumina cement; mixed cement such as blast furnace cement; special cement such as expansion cement is used. on the other hand,
As the siliceous material, for example, crystalline silica such as silica sand and silica powder; and amorphous silica such as fly ash, silica fume, blast furnace slag, and diatomaceous earth are used. The proportion of calcareous and silicic acid in the hydraulic inorganic material is not particularly limited, but the weight of the former is often 0.5 to 1.2 relative to the weight of the latter.

The skeleton 1 has a mortar layer 4 applied to the finished surface side of the skeleton 2 via a mold 2. When applying the mortar layer 4, a part of the mortar is injected into the dovetail groove 3 or the dovetail hole provided in the formwork 2 and hardened, so that the formwork 2 and the mortar layer 4 are firmly joined. In the present invention, the dovetail groove 3
Means a groove having a dove-tail-shaped cross section and is provided mainly for the purpose of preventing peeling of the mortar layer 4. Therefore, the groove does not need to be continuous and may be continuous. Also, the dovetail hole is
A hole whose cross section expands toward the bottom. The width or the equivalent diameter of the dovetail groove or dovetail hole is usually 3 to 50 mm,
It is preferably 5 to 30 mm. Depth is typically 0.5
It is -10 mm, preferably 1-5 mm. As it deviates from this range, the above-mentioned effect of preventing peeling and the economical efficiency decrease. The pitch of the dovetail groove 3 or the dovetail hole is determined by the size of the mold 2 and the weight of the finishing material. The dovetail groove 3 may be provided in any direction, but it is preferable to provide the dovetail groove 3 in the height direction so that air can easily escape when pouring concrete.
The dovetail groove 3 and the dovetail hole may coexist.

Further, such dovetail groove 3 or dovetail hole is
It is provided at least on the concrete pouring side of the form 2, but it is preferable to provide it on both the concrete pouring surface side and the finishing surface side in order to more firmly bond the skeleton 1 and the mortar layer 4. When installing only on the concrete pouring side,
For example, the frame 1 and the form 2 can be joined securely with screws or the like.

Next, the permanent mold 2 of the present invention is known in which a hydraulic inorganic substance and a predetermined additive containing water are mixed with a mixer, and the mixture is poured into the mold to be cured and then demolded. It can be manufactured by adopting the above method. However, it is preferable to manufacture by extruding a mixture of a hydraulic inorganic substance, a reinforcing material, an extrusion aid and water, and then curing and curing the molded product. The preferred manufacturing method of the present invention will be described below. In the following description, the parts regarding the amounts of the components mean the parts by weight of each component with respect to 100 parts by weight of the hydraulic inorganic material.

As the hydraulic inorganic substance, those already described can be adopted. Reinforcing materials include inorganic fibers such as glass fiber, carbon fiber, rock wool, and asbestos; organic synthetic fibers such as polyacrylonitrile-based, polyolefin-based, polyvinyl alcohol-based; organic natural fibers such as hemp and pulp; wollastonite, titanium Examples thereof include fibrous powders such as potassium acid and edenite. Above all, a hydraulic substance to which wollastonite is added may be used in the present invention. In that case, wollastonite is added in an amount of about 1 to 30 parts, and depending on the purpose, 5 to 20 parts. In addition, organic synthetic fibers and pulp may be blended. When using an organic synthetic fiber, a polyacrylonitrile fiber excellent in adhesiveness with a hydraulic substance is preferable, and the fiber length is 0.5 to 10 m.
m, preferably 2 to 6 mm. This may be further fibrillated. The organic synthetic fiber and pulp are mixed in an amount of 0.5 to 5 parts, preferably 1 to 3 parts. These reinforcing materials may be mixed and used.

Examples of the extrusion aid include cellulose derivatives that impart water retention, thickening and fluidity during kneading and molding. Examples of the cellulose derivative include methyl cellulose, hydroxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxypropyl ethyl methyl cellulose and the like. You may mix and use these cellulose derivatives. The cellulose derivative is 0.3 to 3 parts, preferably 0.5 to
Add 1.5 parts. Further, in order to improve the fluidity at the time of molding, 1 to 30 parts, preferably 5 to 20 parts of at least one of talc, mica, chlorite, etc.
Parts may be added. In addition, sepiolite, bentonite, zeolite, superabsorbent resin, or the like may be added to improve water retention during molding. In addition to the extrusion aid, perlite, shirasu balloon, glass balloon, synthetic resin foam beads, etc. may be blended in order to reduce the weight of the molded product.

Powders containing the above-mentioned hydraulic inorganic substance, reinforcing material and extrusion aid are mixed, and water is added to this mixture and kneaded. It is preferable to inject the water in the form of a spray or a shower because the water is well dispersed and kneaded. The amount of injected water is about 18 to 35 parts, preferably about 20 to 30 parts.

When an aqueous solution containing an aliphatic polymer having a water-soluble sulfonate and / or carboxylate is used as water to be injected into the powder mixture, the affinity between the powder mixture and water is improved. However, it is preferable. As such an aliphatic polymer, for example, a polymer of acrylic acid, methacrylic acid, maleic acid or fumaric acid, and a salt of a polycarboxylic acid polymer which is a copolymer of these compounds and other vinyl compounds. A sulfonic acid salt of a conjugated diene compound polymer such as butadiene or isoprene; and a sulfonic acid salt of a polymer having a highly flexible aliphatic polymer such as a sulfonic acid salt of a copolymer of a conjugated diene compound and a carboxylic acid Salts and / or carboxylates are used. Examples of the sulfonate and / or carboxylate include alkali metal salts, alkaline earth metal salts, ammonium salts and amine salts. Among these, alkali metal salts are preferable, and sodium salt is particularly preferable. A conjugated diene polymer having a small influence on the hydration reaction of a hydraulic inorganic substance and having a large penetrating effect, particularly an isoprene polymer, is preferable. The sulfonate and / or carboxylate of the above aliphatic polymer is added in an amount of 0.05 to 2 parts, preferably 0.1 to 0.5 parts.

The kneaded product thus obtained is extruded using a vacuum extruder. A known vacuum extruder may be used. Among the extruders, it is convenient to use a two-stage vacuum extruder having a vacuum degassing chamber in the middle. To form the dovetail grooves in the extruded body, a die having an appropriate shape may be used. Further, the dovetail groove and the dovetail hole can be formed by using an embossing roller or a press which is expanded by a gas or a liquid or which utilizes viscoelasticity of a fluid and which has a protrusion made of rubber or plastic. Then, the extruded body is cured and hydrated and hardened. As the curing method, natural curing, steam curing, autoclave curing, or the like can be performed alone or in combination depending on the molded body.

At the time of construction of a concrete structure, the permanent formwork of the present invention manufactured as described above is used to construct concrete by pouring concrete, and the finished surface side of the formwork is directly removed without demolding. Apply mortar to. A tile 5 can be attached to the surface or spray coating can be applied to form a strong finished surface without peeling.

[0017]

Example: Portland cement 65 parts and silica powder 35
And 100 parts of a hydraulic inorganic material consisting of 10 parts of polyacrylonitrile fiber (Atlan (registered trademark): fiber length 2 m)
m: Toray Co., Ltd.) 2 parts, pulp 1 part and hydroxypropylmethylcellulose powder (Metroses (registered trademark): 90SH30000: Shin-Etsu Chemical Co., Ltd.) 1
Parts were added and powder mixed. Then, sodium polyisoprene sulfonate (Dynaflow (registered trademark) Z10
5: Japan Synthetic Rubber Co., Ltd.) 21 parts of an aqueous solution in which 0.25 parts was dissolved was added by spraying to form a slurry. This slurry is fed to a two-stage extruder and has a width of 1 on one side.
It was extruded into a plate shape having a thickness of 0 mm and a dovetail groove having a depth of 2 mm and a thickness of 20 mm. The extruded product was naturally cured for a whole day and night, and then cured in steam at 60 ° C. for 12 hours to produce a molded plate. The molded plate had a specific gravity of 1.7 and a bending strength of 320 kg / cm ² . Next, concrete is placed using this forming plate as a formwork, and then Portland cement, sand, and sand are provided on the finishing surface side of the formwork having the dovetail groove.
Mortar consisting of SBR latex and methyl cellulose was applied so as to have a thickness of 5 mm to form a mortar layer, which was brought into close contact with the back surface of the tile. After construction, it was hardened sufficiently and then the mortar layer was forcibly destroyed, but it did not peel off at the interface between the mold and the mortar layer.

[0018]

EFFECT OF THE INVENTION The formwork of the present invention is a hydraulic inorganic material type formwork and is used for placing concrete as a skeleton. However, it can be removed as it is even after placing concrete. Without joining, it is firmly joined to the cast concrete and integrated to form the surface part of the skeleton. Since at least the finishing surface side of this formwork is provided with pre-existing grooves or dovetail holes, when applying the mortar layer, part of the mortar is injected into the dovetail grooves or dowel holes provided in the formwork. After hardening, the mold, that is, the skeleton and the mortar layer are firmly bonded. Therefore, peeling and floating of the mortar layer are suppressed, and there is an effect of preventing an accident such as peeling of the finishing material. When the dovetail groove or dovetail hole is provided on both the concrete placing surface side and the finishing surface side, the concrete portion of the skeleton and the formwork should also be joined more firmly to ensure completeness. You can

If this mold is manufactured by extrusion molding using a mixture of a reinforcing material, an extrusion aid and water as a raw material, the mold becomes strong due to the addition of the reinforcing material and the extrusion molding. The formation of the dovetail groove and the like becomes easy, and the mold having high dimensional accuracy can be efficiently manufactured. If a concrete structure is constructed using this formwork, there is no need for demolding work or special work for the foundation of the mortar layer, which promotes construction and is economical. In addition, the structure is safe because the mortar layer is not peeled or lifted, and management and repair costs are saved.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of a concrete structure constructed using the formwork of the present invention.

[Explanation of symbols]

1: frame 2: formwork 3: dovetail groove 4: mortar layer 5: tile 6: joint

Claims (4)

[Claims] 1. A permanent mold of hydraulic inorganic material, which is provided with a groove or a hole on the finished surface side. 2. A permanent set of hydraulic inorganic material form having grooves or holes on the concrete pouring surface side and the finishing surface side. 3. The method according to claim 1, wherein a mixture of a hydraulic inorganic substance, a reinforcing material, an extrusion aid and water is extrusion-molded, and then the molded product is cured to form a permanent mold. Manufacturing method of permanent formwork. 4. In the construction of a concrete structure, concrete is cast using the permanent formwork according to claim 1 to construct a skeleton, and the finished surface of the permanent formwork without demolding. A method for constructing a concrete structure, characterized in that a mortar is applied to the side and a finishing surface is applied.