JP7374805B2 - Formwork for concrete forming and concrete manufacturing method - Google Patents

Description

The present invention relates to a concrete forming form and a concrete manufacturing method used mainly in the fields of architecture and civil engineering, and more particularly to a concrete forming form suitable for forming concrete with protrusions and a concrete manufacturing method. It is something.

Conventionally, a formwork as shown in Patent Document 1, for example, is known as a formwork that can give a wood-like appearance to the surface of concrete. This formwork includes a wood-based formwork body and a porous layer made of hydrophobic oxide fine particles provided on the surface of the formwork body. According to this formwork, it is possible to suppress the seepage of components such as lignin from the formwork, and to reduce depressions such as air pockmarks that occur on the concrete surface.

FIG. 3 is an example of a wood-like finishing of concrete using a cedar board Honji form as described in Patent Document 1. When finishing concrete with a wood look, decorative joints are generally provided between the planks. Figure 4 shows an example of protruding joints provided on the concrete surface.

Patent No. 6461648

However, as shown in FIG. 5, the protruding joints provided on the concrete surface may be chipped during demolding. If the exposed joints are chipped, the aesthetic appearance of the concrete will be compromised, so there was a need for a forming technology that can prevent the chipping of the exposed joints.

The present invention has been made in view of the above, and an object of the present invention is to provide a formwork for concrete forming and a method for manufacturing concrete that can prevent loss of exposed joints.

In order to solve the above-mentioned problems and achieve the objects, a formwork for concrete forming according to the present invention is provided with a water-repellent layer having a contact angle with water of 130° or more on at least a part of the mold surface. The formwork further includes a recessed groove section provided on the surface of the formwork body for forming a protrusion on the concrete surface, and the recessed groove section is inclined so that the width of the groove increases as it approaches the surface in cross-sectional view. It has a tapered surface, and the inclination angle of the tapered surface with respect to the surface of the formwork body is set in the range of 45° to 60°.

Further, another formwork for forming concrete according to the present invention is characterized in that, in the above-mentioned invention, concrete having a strength after hardening is in the range of 15 to 30 N/mm ² is to be formed.

Further, another formwork for concrete forming according to the present invention is characterized in that, in the above-mentioned invention, the groove width of the groove portion on the surface of the formwork body is set in a range of 2 to 5 mm.

Further, another formwork for forming concrete according to the present invention is a formwork having a mold surface capable of imparting a wood-like appearance to the concrete surface, or a wood-based formwork made of a wood material in the above-mentioned invention. It is characterized by

Further, another formwork for concrete forming according to the present invention is characterized in that the water-repellent layer is a porous layer formed from hydrophobic oxide fine particles in the above-mentioned invention.

Moreover, the method for producing concrete according to the present invention is a method for producing concrete having protrusions on the surface using the above-described concrete forming form, in which fresh concrete is poured into the concrete forming form, and the concrete is It is characterized by being demolded after curing.

According to the formwork for concrete forming according to the present invention, the formwork for concrete forming is provided with a water-repellent layer having a contact angle with water of 130° or more on at least a part of the mold surface, and The groove further includes a concave groove section for forming a protrusion on the concrete surface, and the concave groove section has an inclined tapered surface so that the groove width increases as it approaches the surface in cross-sectional view, and the concave groove section Since the inclination angle of the tapered surface is set in the range of 45° to 60°, it is possible to prevent concrete from adhering to the form body during demolding. Therefore, it is possible to reduce defects at the exposed joints.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a concrete forming form according to the present invention. FIG. 2 is a diagram showing the results of verifying the effects of the present invention. FIG. 3 is a photographic diagram showing an example of a wood-like finish on concrete. FIG. 4 is a photographic diagram showing an example of exposed joints in wood-like finishing of concrete. FIG. 5 is a photographic diagram showing the appearance of chipping at the exposed joint.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a concrete forming form and a concrete manufacturing method according to the present invention will be described in detail below based on the drawings. Note that the present invention is not limited to this embodiment.

[Formwork for concrete molding]
First, a concrete forming form according to the present embodiment will be explained.
As shown in FIG. 1, a concrete forming form 10 according to the present embodiment is a form for forming concrete C, and includes a form body 12 and a surface 14 (mold surface) of the form body 12. ), and a water-repellent layer 18 provided on the surface 14 of the form body 12 including the groove 16. In the illustrated example, the formwork main body 12 is bonded to the surface of the base material 20 and arranged. Furthermore, although the concave groove portion 16 is formed by butting and arranging the ends of two formwork bodies 12 whose ends are cut diagonally, they may be formed by other methods.

The materials of the form body 12 and the base material 20 are not limited as long as they are commonly used, and can be selected from wood, metal, synthetic resin, natural resin, composite materials thereof, and the like. Generally, it is preferable to use wood or painted plywood in terms of cost and versatility. When constructing a high-grade exposed concrete structure with a wood-like surface, it is more preferable to use a wood-based formwork made of a wood material such as real cedar board or larch plywood. Moreover, the shape, size, etc. of the form body 12 and the base material 20 can be appropriately designed depending on the intended concrete molded body. The surface 14 of the formwork main body 12 is capable of imparting a wood-like appearance to the surface of the concrete C, and has, for example, a wood-like uneven pattern formed on this surface.

The groove portion 16 is a V-shaped groove for forming a protrusion on the concrete surface. When concrete enters this groove 16, a protrusion is formed on the concrete surface. The groove portion 16 has a tapered surface 22 that is inclined so that the groove width B increases toward the surface 14 in a cross-sectional view. The inclination angle θ of the tapered surface 22 with respect to the surface 14 of the form body 12 is preferably 45° or more, and preferably set in the range of 45° to 60°. Further, the groove width B of the concave groove portion 16 on the surface 14 of the form body 12 is preferably 2 mm or more, and preferably set in the range of 2 to 5 mm.

The cross-sectional shape of the groove portion 16 is not limited to a V-shape, but may be any shape as long as it has a tapered surface 22 that is inclined so that the groove width B increases toward the surface 14. For example, it may be approximately U-shaped, with the top of the V-shape being flat. In the case of a substantially U-shape, the inclined tapered surface 22 and the inner ends of the tapered surfaces 22 may be connected by a groove inner surface parallel to the surface 14. In this case, the inclination angle θ of the tapered surface 22 is also preferably 45° or more, and preferably in the range of 45° to 60°. Furthermore, the groove width B of the concave groove portion 16 on the surface 14 of the form body 12 is preferably 2 mm or more, and preferably set in the range of 2 to 5 mm.

In order to prevent damage to the exposed joints during demolding, the strength of the concrete C to be formed after hardening is preferably 15 N/mm ² or more, and more preferably 20 N/mm ^{2 or} more. In order to reduce adhesion of concrete to the formwork 10 during demolding, the strength after curing is preferably in the range of 15 to 30 N/mm ² .

The water-repellent layer 18 is a layer having a water-repellent surface having a contact angle with water of 130° or more, more preferably a super-hydrophobic surface having a contact angle of 150° or more. Here, water repellency refers to a property that indicates difficulty in getting wet by water, and the contact angle of a water droplet placed on a solid surface (in the present invention, the surface of the water repellent layer 18) is an index of water repellency. . In general, a contact angle of 90° or more is considered water repellent, a contact angle of 110° to 150° is considered highly water repellent, and a contact angle of 150° or more is considered super water repellent. Even if the surface free energy of the material is lowered, the contact angle is said to be limited to 120°, and in order to achieve a contact angle higher than that, it is necessary to process the surface shape into a special shape as described below.

The water-repellent layer 18 includes, for example, a base layer provided on the formwork body 12, a filled particle-containing layer provided on this base layer, and a super water-repellent porous layer provided on this filled particle-containing layer. It can be composed of layers. The porous layer is formed of, for example, hydrophobic oxide fine particles, and is arranged on the outermost surface of the surface 14 on the side that comes into contact with the concrete C.

According to the above configuration, the surface tension of the surface 14 of the form body 12 is significantly increased by the water-repellent layer 18, so that when air bubbles in the concrete entrained during pouring come into contact with the surface of the water-repellent layer 18, , it becomes easier to spread along this surface, and the air bubbles on the concrete surface become thinner and flatter along the surface than before. Furthermore, the air bubbles rise due to small vibrations applied from outside the form body 12 by a hammer or the like, and easily escape from the surface of the concrete. Therefore, air bubbles that cause air pockmarks on the concrete surface can be more reliably reduced.

In addition, the water-repellent layer 18 can suppress components from the formwork body 12 (for example, components such as lignin when the formwork body 12 is a wood-based formwork) from seeping into the concrete C side. Furthermore, due to the super water-repellent effect of the water-repellent layer 18, the occurrence of depressions such as air pockmarks on the surface of the concrete C after molding can be significantly reduced, and the design of the concrete surface can be improved. In addition, the super water-repellent effect of the water-repellent layer 18 prevents adhesion between the concrete C and the formwork 10, making it possible to remove the form cleanly, making it easier to reuse the formwork 10, and reducing the environmental burden. lead to reduction.

Furthermore, the groove portions 16 and the water-repellent layer 18 can prevent concrete at the exposed joints from adhering to the form body 12 during demolding. Therefore, it is possible to reduce defects at the exposed joints.

FIGS. 2(1) and 2(2) show the appearance of a concrete surface formed using the concrete forming form 10 of this embodiment. As shown in this figure, it can be seen that the exposed joints are formed on the concrete surface without any defects. Therefore, according to the present embodiment, it is possible to significantly reduce loss of exposed joints compared to the conventional formwork (see FIG. 5).

Next, the specific structure and function of the base layer, porous layer, and filler particle-containing layer for forming the water-repellent layer 18 will be explained.

[Base layer]
The base layer is composed of a coating film applied to the surface 14 of the form body 12, such as an undercoat coating, a filler coating, a primer coating, or a colored coating. By interposing the base layer between the surface 14 and the porous layer, it is possible to correct the unevenness of the surface 14, improve the adhesion of the porous layer and the layer containing filler particles, and improve the durability of the form body 12. can. Note that the base layer and the filler particle-containing layer may be interposed as necessary, and a plurality of base layers or any layer other than the base layer may be interposed. The formation of the base layer can be performed using a known coating method using a known undercoat, filler, primer, and coloring agent, and therefore will not be described in detail here.

[Porous layer]
The porous layer is formed on at least a portion of the mold surface (the outermost surface in contact with concrete). The hydrophobic oxide fine particles that are the raw material for forming the porous layer are not particularly limited as long as they have hydrophobicity, and may be made hydrophobic by surface treatment. For example, it is also possible to use hydrophilic oxide fine particles whose surface is made hydrophobic by subjecting them to surface treatment with a silane coupling agent or the like. The type of oxide is also not particularly limited as long as it has hydrophobicity. For example, at least one of silica (silicon dioxide), alumina, titania, etc. can be used. These may be publicly known or commercially available ones.

For example, as for silica, the product names are "AEROSIL R972", "AEROSIL R972V", "AEROSIL R972CF", "AEROSIL R974", "AEROSIL RX200", "AEROSIL RX300", "AEROSIL NX90G", " AEROSIL RY200” (the above, Nippon Aerosil Co., Ltd.), "AEROSIL R202", "AEROSIL R805", "AEROSIL R812", "AEROSIL R812S" (manufactured by Evonik Degussa), "Silohovik-100", "Silohovik-200" , "Silohobic-603" (manufactured by Fuji Silysia Chemical Co., Ltd.), and the like. Note that AEROSIL and Cylohobic are registered trademarks.

Examples of titania include the product name "AEROXIDE TiO2 T805" (manufactured by Evonik Degussa). Examples of alumina include fine particles such as product name "AEROXIDE Alu C" (manufactured by Evonik Degussa), which are treated with a silane coupling agent to make the particle surface hydrophobic. Note that AEROXIDE is a registered trademark.

Among these, hydrophobic silica fine particles can be preferably used. In particular, hydrophobic silica fine particles having trimethylsilyl groups on the surface are preferred in that they provide better water repellency. Commercial products corresponding to this include, for example, the above-mentioned "AEROSIL RX200", "AEROSIL RX300", "AEROSIL NX90G" (manufactured by Nippon Aerosil Co., Ltd.), "AEROSIL R812", "AEROSIL R812S", "AEROSIL R8200" ( (manufactured by Evonik Degussa), etc.

Although the particle size of the hydrophobic oxide fine particles is not limited, it is preferable that the average primary particle diameter is 3 nm to 10 μm, more preferably 3 to 100 nm, and most preferably 5 to 50 nm. By setting the average diameter of the primary particles within the above range, gas such as air can be retained in the voids in the aggregate, resulting in a porous structure and excellent mold releasability. This agglomerated state is maintained even after adhering to at least a portion of the mold surface (the outermost surface in contact with concrete), so excellent mold releasability can be exhibited. In particular, by using hydrophobic oxide fine particles having an average primary particle diameter of 3 to 100 nm, it is possible to obtain a concrete forming form 10 having a surface with a three-dimensional network porous structure.

The porous layer of hydrophobic oxide fine particles formed on the outermost surface of the mold surface is preferably porous with a three-dimensional network structure, and its thickness is preferably about 0.1 to 500 μm, with a thickness of about 0.1 to 500 μm. More preferably, the thickness is about 5 to 20 μm. By forming the layer in such a porous state, the layer can contain a large amount of air and exhibit better mold release properties.

In the present invention, the primary particle average diameter can be measured using a scanning electron microscope (FE-SEM), and if the resolution of the scanning electron microscope is low, other electron microscopes such as a transmission electron microscope may be used. A microscope may also be used in combination. Specifically, if the particle shape is spherical, the diameter is considered to be the diameter, and if the particle shape is non-spherical, the average value of the longest diameter and the shortest diameter is regarded as the diameter, and 50 particles are arbitrarily selected by observation using a scanning electron microscope etc. Let the average diameter of the particles be the primary particle average diameter.

The specific surface area (BET method) of the hydrophobic oxide fine particles is not particularly limited, but is usually preferably 50 to 300 m ² /g, more preferably 100 to 300 m ² /g.

When applying to at least a part of the mold surface (the outermost surface in contact with concrete), the hydrophobic oxide particles may be applied as is (dry method), or the hydrophobic oxide particles may be dispersed in a solvent. It may also be applied by coating a dispersion liquid (wet method). In the present invention, the latter wet method is preferred from the viewpoint that it is easy to obtain an industrially uniform coating film (hydrophobic oxide fine particle layer) and also to easily obtain a three-dimensional network structure.

When using the above dispersion liquid, the solvent used in the dispersion liquid is, for example, alcohol (ethanol), cyclohexane, toluene, acetone, IPA, propylene glycol, hexylene glycol, butyl diglycol, pentamethylene glycol, normal pentane, normal hexane, Organic solvents such as hexyl alcohol can be selected as appropriate. At this time, trace amounts of dispersants, colorants, antisettling agents, viscosity modifiers, etc. can also be used in combination. The amount of hydrophobic oxide fine particles dispersed in the solvent is usually about 10 to 300 g/L (liter), preferably about 30 to 100 g/L.

Furthermore, the method of applying the dispersion liquid is not limited, and in addition to application methods such as spraying, brushing, roller, and dipping, printing methods (inkjet printing, screen printing, gravure printing), dripping methods, etc. can also be adopted. can. After coating, it may be dried appropriately at room temperature to about 150°C.

The amount of hydrophobic oxide fine particles applied to the mold surface can usually be set as appropriate depending on the desired mold release property, etc., but it is, for example, about 0.1 to 100 g/m ² on a solid content basis. , preferably about 0.5 to 20.0 g/m ² . By setting it within the above range, it is possible to obtain better mold releasability over a long period of time, and it is also more advantageous in terms of suppressing drop-off of hydrophobic oxide fine particles and reducing costs.

[Filled particle containing layer]
Preferably, the filled particle-containing layer is interposed between the surface 14 and the porous layer. The filled particle-containing layer is a layer in which filled particles are dispersed in a matrix. By interposing this layer containing filled particles, the releasability of the concrete molding form 10 can be maintained for a longer period of time. As the filled particles, filled particles containing at least one of an organic component and an inorganic component can be employed. When the filled particle-containing layer is interposed between the surface 14 and the porous layer, the amount applied is, for example, about 0.1 to 100 g/m ² based on solid content, preferably 1.0 to 20.0 g/m ² It is sufficient to set the degree. By setting within the above range, it is possible to obtain better adhesion of the hydrophobic oxide fine particles over a long period of time, and also to prevent the hydrophobic oxide fine particles coated on the filled particle-containing layer from falling off, improve durability, etc. It is also advantageous in terms of The method for applying the filled particle-containing layer is not particularly limited, and for example, coating methods such as spraying, brushing, roller, dipping, etc., as well as printing methods, dropping methods, etc. can be employed. At the time of application (coating), the following matrix can be diluted with an appropriate solvent, and after application, it may be appropriately dried at room temperature to about 150°C.

Examples of inorganic components include 1) metals such as aluminum, copper, iron, titanium, silver, and calcium, or alloys or intermetallic compounds containing these; 2) silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, iron oxide, etc. Oxides, 3) inorganic or organic acid salts such as calcium phosphate and calcium stearate, 4) glass, and 5) ceramics such as aluminum nitride, boron nitride, silicon carbide, and silicon nitride, etc. can be suitably used.

Examples of organic components include acrylic resins, urethane resins, melamine resins, amino resins, epoxy resins, polyethylene resins, polystyrene resins, polypropylene resins, polyester resins, cellulose resins, vinyl chloride resins, and polyvinyl. Organic polymer components (or resin components) such as alcohol, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, polyacrylonitrile, polyamide, etc. can be suitably used.

As the filled particles, in addition to particles made of an inorganic component or particles made of an organic component, particles containing both an inorganic component and an organic component can be used. Among these, it is particularly preferable to use at least one of acrylic resin particles, polyethylene resin particles, hydrophilic silica particles, calcium phosphate particles, charcoal powder, calcined calcium particles, uncalcined calcium particles, calcium stearate particles, and the like.

The average particle diameter of the filled particles (as measured by a laser diffraction particle size distribution analyzer) is preferably about 0.3 to 100 μm, more preferably 1 to 50 μm, even more preferably 5 to 30 μm, and most preferably 20 to 30 μm. If it is less than 0.3 μm, it is unsuitable in terms of handling, unevenness formation, etc. On the other hand, if it exceeds 100 μm, it is unsuitable in terms of shedding of the filled particles, dispersibility, etc. The shape of the filled particles is not limited, and may be, for example, spherical, spheroidal, irregular, teardrop, flat, hollow, porous, or the like.

A thermoplastic resin, thermosetting resin, rubber, elastomer, wax, or the like can be used as the matrix that constitutes the filled particle-containing layer and connects the filled particles. The content of the filled particles in the matrix can be changed as appropriate depending on the material of the matrix, the type of the filled particles, desired physical properties, etc., but in general, it is preferably 1 to 80% by weight based on solid content, and 3 to 80% by weight. More preferably 50% by weight.

The method for incorporating the filled particles (the method for dispersing the filled particles in the matrix) is not particularly limited, but generally, the method for incorporating the filled particles is to add the filled particles to a raw material for forming the matrix (for example, a composition containing a thermoplastic resin). Examples include a method of blending. The mixing method may be dry mixing or wet mixing.

When the matrix is a thermoplastic resin, the main components of the thermoplastic resin layer generally include 1) a thermoplastic resin or a monomer or oligomer constituting it, 2) a solvent, and 3) a crosslinking agent, etc. as necessary. Filler particles may be added and mixed into the mixture. As the thermoplastic resin, a known thermoplastic resin can be used. For example, in addition to acrylic resin, polystyrene, ABS resin, vinyl chloride resin, polyethylene resin, polypropylene resin, polyamide resin, polycarbonate, polyacetal, fluorine resin, silicone resin, polyester resin, etc., blend resins of these resins, A copolymer, a modified resin, etc. containing a combination of monomers can be used.

When the matrix is a thermosetting resin, for example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, silicone resin, etc. can be employed. When the matrix is an elastomer, for example, a PVC-NBR blend elastomer, a urethane elastomer, etc. can be employed.

[Concrete manufacturing method]
Next, a method for manufacturing concrete according to the present embodiment will be explained.
The concrete manufacturing method according to the present embodiment is a method for manufacturing concrete having protruding joints on the surface using the above-described concrete forming form 10, in which fresh concrete is poured into the concrete forming form 10, It is removed from the mold after the concrete has hardened. Therefore, constructing concrete having protruding joints as shown in FIG. 2 using the concrete forming form 10 corresponds to the implementation of the present invention.

According to this embodiment, the concave grooves 16 and the water-repellent layer 18 provided in the concrete molding form 10 can prevent concrete at the exposed joints from adhering to the form body 12 during demolding. . Therefore, the protruding joints on the concrete surface can be formed without chipping.

FIGS. 2(1) and 2(2) show the appearance of the concrete surface formed by the concrete forming form 10. As shown in this figure, according to this embodiment, defects at exposed joints can be significantly reduced compared to the conventional formwork (see FIG. 5).

As explained above, according to the concrete forming form according to the present invention, the concrete forming form is provided with a water-repellent layer having a contact angle with water of 130° or more on at least a part of the mold surface, The formwork body further includes a concave groove portion provided on the surface of the formwork body for forming a protrusion on the concrete surface, and the concave groove portion has an inclined tapered surface such that the groove width increases as it approaches the surface in cross-sectional view. Since the angle of inclination of the tapered surface with respect to the surface of the formwork body is set in the range of 45° to 60°, it is possible to suppress adhesion of concrete to the formwork body during demolding. Therefore, it is possible to reduce defects at the exposed joints.

As described above, the concrete forming form and concrete manufacturing method according to the present invention are useful for constructing high-grade fair-faced concrete with a wood-like surface, and particularly reduce defects at protruding joints provided on the concrete surface. suitable for.

10 Formwork for concrete forming 12 Formwork body 14 Surface (mold surface)
16 Concave groove 18 Water repellent layer 20 Base material 22 Tapered surface C Concrete

Claims (4)

A concrete molding form having a mold surface capable of imparting a wood-like appearance to the concrete surface, and comprising a water-repellent layer having a contact angle with water of 130° or more on at least a part of the mold surface,
The method further includes a concave groove provided on the surface of the form body to form a protrusion on the concrete surface, and the concave groove is inclined so that the width of the groove increases as it approaches the surface of the form body in cross-sectional view. It has a pair of tapered surfaces, and the inclination angle (θ) of the tapered surfaces with respect to the surface of the form body is set in the range of 45° to 60° , respectively ,
A formwork for concrete forming, characterized in that a groove width of the groove portion on the surface of the formwork body is set in a range of 2 to 5 mm . In order to mold concrete having a compressive strength in the range of 15 to 30 N/mm ² after hardening, the form body is made of wood, metal, synthetic resin, natural resin, or a composite material thereof. The formwork for concrete forming according to claim 1. The concrete molding form according to claim 1 or 2, wherein the water-repellent layer is a porous layer formed from hydrophobic oxide fine particles. A method for producing concrete having protrusions on the surface using the concrete forming form according to any one of claims 1 to 3 , comprising:
A concrete manufacturing method characterized by pouring fresh concrete into a concrete molding form and removing the mold after the concrete has hardened.

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