JPH0791012A - Discoloring preventing method for colored concrete - Google Patents

Abstract

PURPOSE:To provide discoloring preventing method for colored concrete which is free from discoloring with the lapse of time and excellent in durability. CONSTITUTION:Using colored pigment 3' in which blast furnace slag particles 12, cement particles 6, and colored pigments 10 are attached to the outer periphery of a crashed stone particle 4, a decorative form on the surface of which the many colored pigments 3' are distributed is prepared. With its surface used as contact surface, concrete material is deposited and cured, and then the decorative form is separated to transfer the colored pigments 3' to the surface layer of a concrete product and apply color onto the surface of the concrete.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing discoloration of colored concrete products.

[0002]

2. Description of the Related Art Conventionally, when coloring the surface of a concrete product (for example, a concrete wall), a colored film is formed on the surface of the concrete product with a paint or the like. However, the paint contains an organic material as a main component and deteriorates with time, so that the pigment comes off. Therefore, there was a problem in durability. Therefore, recently, the following method proposed by the present inventor has been implemented.
First, as shown in FIG. 4, a hard urethane decorative frame 1 with color pigments 3 is prepared. The surface of the decorative form 1 is formed as an uneven pattern transfer surface, and a water-soluble adhesive is applied to the surface to form an adhesive layer 2. A large number of color pigments 3 are attached to the surface of the adhesive layer 2. FIG. 5 shows the coloring pigments 3 in an enlarged manner. As shown in the figure, the color pigments 3 are formed by using crushed stone particles 4 of natural stone as a core and arranging the color pigment 5 around the core. The color pigment 5 is used as a colorant for making the color colored by the natural crushed stone particles 4 more natural. The cement particles 6 act as an adhesive for adhering the colored pigment 5 to the natural crushed stone particles 4. Next, as shown in FIG. 6, the decorative formwork 1 is attached to the surface of the mold material 7 with the surface on which the color pigments are distributed facing inward. Then, a concrete material 8 is cast by using this mold material 7 and another mold material 7'as a support, and cured and hardened. Then, as shown in FIG. 7, the decorative formwork 1 and the mold material 7 are formed into a concrete wall 9
Peel from. In this case, the coloring pigments 3 have migrated into the surface layer of the concrete wall 9, and the adhesive layer 2 that fixed the coloring pigments 3 to the surface of the decorative form 1 when the decorative form 1 was removed is the concrete material. The makeup form 1 can be easily removed because it has dissolved and disappeared due to moisture in the interior.

[0003]

However, recently, the concrete surface colored by the above method is
In some cases, it has been found that there is a problem that the colored color fades with the lapse of time. Therefore, the present inventor has conducted a series of studies on the cause of fading of concrete walls and the like. As a result, it was found that the above-mentioned fading was mainly caused by the color pigment attached to the outer periphery of the natural crushed stone grains flowing out to the outside with time. That is, inside the hardened concrete, there are gaps formed between the cement particles, and the gaps are communication holes inside the concrete. The communication hole has a function of absorbing and draining water inside the concrete and water in the atmosphere, and has a function of discharging and transferring various components inside the concrete to the outside. This is also clear from the white sinter phenomenon of concrete (a phenomenon in which CaO component in concrete is exposed to the atmosphere on the concrete surface and adheres in a cloudy state). That is, as shown in FIG. 8 which is an enlarged view of the concrete wall surface, in the colored pigments 3 transferred to the surface layer of the concrete wall 9, the colored pigments 5 among them are the natural crushed stone particles 4 and the cement particles due to the water absorption and drainage action. It is released from 6, transferred to the surface of the concrete wall 9 and washed away by rain, wind, etc. As a result, it was found that the color of the surface of the concrete wall 9 faded. Therefore, this inventor
As a method for preventing the elution of the pigment due to the water absorption / drainage action of the concrete, an attempt was made to prevent the elution of the pigment by increasing the particle diameter of the pigment. However, in this method, there is a limit to the uniform coloring expression on the concrete surface due to the large diameter of the pigment (the pigment is dispersed in spots on the colored surface), and a countermeasure against it has been desired.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for preventing discoloration of colored concrete which does not discolor due to changes with time.

[0005]

In order to achieve the above object, a method for preventing discoloration of colored concrete according to the present invention is to prepare a decorative form having a large number of colorants distributed on its surface.
In the method for coloring a concrete surface, which comprises placing a concrete material with its surface as a contact surface, curing and curing, and then transferring the coloring material to the surface layer of the concrete product by peeling off the decorative formwork, the coloring material As the above, a configuration is used in which color pigments and blast furnace slag powder are used.

[0006]

That is, the present inventor further advanced the research as a method of preventing the color pigment from falling off, focusing on avoiding the hollowing of concrete. As a result, water-soluble calcium hydroxide [Ca (OH) ₂ ] in concrete
Paying attention to the fact that elution to the concrete surface by the water absorption and drainage action further promotes cavitation inside the concrete, and as a method for preventing the elution of this calcium hydroxide, by reacting the blast furnace slag with calcium hydroxide, It has been found that a dense structure is formed by forming calcium silicate hydrate. Based on this knowledge, the present inventor has arrived at the present invention by conceiving that the dropping of the color pigment can be avoided by the above action by transferring the blast furnace slag powder to the concrete surface. As a result, fading of the surface of the concrete product can be prevented, and long-term durability and strength are significantly improved.

Next, the present invention will be described in detail.

As a method for preventing discoloration of colored concrete according to the present invention, first, coloring is applied to the concrete surface by transferring a decorative formwork in which a large number of color pigments are distributed via an adhesive layer or the like onto the concrete surface. In the method, as the color pigments, color pigments in which particles of blast furnace slag powder are attached to the outer circumference of crushed stone particles are used. Here, the color pigments to which the blast furnace slag particles are attached are as shown in FIG.
Not limited to the crushed stone particles 4 provided on the core and the colored pigments 5 on the outer periphery thereof as shown in (4), the whole colored pigments include crushed stone particles or colored pigments.

Colored pigments obtained by adhering blast furnace slag particles around the crushed stone particles (hereinafter referred to as "colored pigments")
As an example, the one shown in FIG. 1 is used.
This is constituted by adhering a color pigment 10 (for example, a particle size of 0.5 to 10 μm, preferably a particle size of 1 to 5 μm) and a blast furnace slag particle 12 to the surface of the crushed stone particles 4. 6
Is a cement particle, and the color pigment 10 and the blast furnace slag particle 12 are bonded to the crushed stone particle 4. Examples of the crushed stone particles 4 include crushed stone particles of natural stone, ceramic particles, glass particles, and the like, and it is preferable to use crushed stone particles of natural stone having various colors, and a particle diameter of 0.3 to 7 mm, and preferably Is 0.5
The thing of -2 mm is used. As the coloring pigment 10, it is preferable to use an inorganic pigment having excellent durability without fear of discoloration, fading, deterioration or the like. Moreover, you may use the special pigment which made the inorganic pigment adhere to the outer periphery of fine natural crushed stone, a ceramic particle, and a glass particle by baking process. The color pigment 10 preferably has a particle size of 1 to 5 μm.

The above-mentioned blast furnace slag powder is generally a melt formed by the reaction of impurities in iron ore with ash of coke and limestone, and its main components are CaO, SiO ₂ and Al ₂ O ₃ . Then, by using the blast furnace slag powder, water-soluble calcium hydroxide [Ca (O
H) ₂ ] to form a calcium silicate hydrate to form a high density layer on the concrete surface by the pozzolanic reaction, thereby suppressing cavitation inside the concrete. The blast furnace slag powder preferably has a maximum particle size of 10 μm or less.

The cement particles are not particularly limited, and various cement powders can be used. The cement powder may be mixed with other water-absorbing inorganic substance powder such as gypsum. Moreover, it does not matter that the other inorganic powders occupy most of them. Adhesion treatment of cement particles made of such cement powder is not particularly limited. For example, the color pigment, the crushed stone particles, the blast furnace slag particles, and the cement particles may be rotationally mixed, and the color pigment, the blast furnace slag particles, and the cement particles may be attached to the outer periphery of the crushed stone particles. In this case, it is preferable that the pigment be slightly moistened. Alternatively, the crushed stone particles, the color pigment, and the blast furnace slag particles may be mixed, the color pigment and the blast furnace slag particles may be attached to the outer periphery of the crushed stone particles, and then the cement particles may be sprayed from the nozzle. As such color pigments, those having a particle size of 0.5 to 10 μm, preferably 1 to 5 μm are used.

Further, as another example of the color pigments, as shown in FIG. 2, a color pigment 11 made of the same material as the color pigment 10 is used as a core, and the blast furnace slag particles 12 and cement particles are provided around the core. 6 is attached as described above.

When the color pigment and the blast furnace slag particles are firmly adhered to the crushed stone particles, it is not always necessary to use the cement particles.

In this method, the coloring pigments as described above are distributed and attached to the surface of the frame of the decorative frame. As a makeup frame,
Those made of hard urethane resin or paper are used. For example, as the mold, a mold made of hard urethane foam and having one surface formed on a color pigment transfer surface for transferring color pigments to the concrete surface by contacting the concrete material is used.

The above color pigments are distributed and adhered to the surface of such a decorative form. Usually, the above color pigments are distributed via a pressure-sensitive adhesive or an adhesive. This kind of adhesive,
As the adhesive, it is preferable to use an adhesive whose adhesive strength and the like are reduced or eliminated by the water content, the alkaline component, etc. in the concrete material. For example, methyl cellulose adhesive,
Examples include polyvinyl alcohol adhesives and water glass. An example of the one that reduces or disappears the adhesive force and the like when it meets the alkaline component in the concrete material is, for example, a two-pack type acrylic adhesive. As a method for distributing the color pigments on the surface of the decorative form via the adhesive,
The above-mentioned coloring pigments are uniformly sprayed on the surface of the decorative form, and then the solution of the adhesive is sprayed and sprayed on the entire surface, or an adhesive layer is formed in advance on the surface of the decorative form. The above-mentioned coloring pigments are evenly dispersed on the above and fixed by utilizing the adhesive force of the adhesive. In addition, instead of the above-mentioned adhesive, paraffin, clay, rubber, resin, etc. are used,
After applying these, the color pigments may be evenly dispersed. In addition, when the surface itself of these decorative formwork has adhesiveness, the said adhesive etc. are not necessarily required.

In this method, the above-mentioned colored pigments are used to apply colored makeup to the surface of a concrete product as follows. That is, the concrete material is cast by setting the color pigment distribution surface of the decorative form as the contact surface with the surface of the concrete product, curing and curing, and then the decorative form is peeled from the surface of the produced concrete product. By this series of steps, the color pigments on the decorative form are transferred to the surface of the concrete product. In this case, as the coloring pigments to be transferred and adhered to the surface of the concrete product, crushed stone particles with blast furnace slag particles attached to the outer periphery are used, so that calcium hydroxide [Ca
(OH) ₂ ] reacts with the blast furnace slag to form calcium silicate hydrate. And since this calcium silicate hydrate adheres to the colored surface layer, the colored pigments are not discharged to the surface of the concrete product due to the water absorption and drainage action inside the concrete product. Therefore,
The coloring pigments on the concrete wall that are colored by rain, wind, etc. will not be washed away, and durability and strength will be greatly improved.

[0017]

As described above, according to the present invention, by transferring blast furnace slag particles to the colored surface of the concrete product, the blast furnace slag particles react with calcium hydroxide in the concrete material to form calcium silicate hydrate. To generate. As a result, in the concrete product surface layer, in order to form a high-density layer due to the fixation of the calcium silicate hydrate or the like, in combination with preventing the elution of calcium hydroxide due to the water absorption and drainage action inside the concrete product,
It is possible to prevent cavitation inside the concrete product. Therefore, it is possible to prevent the colored pigments from flowing out due to the water absorbing and draining action of water and the elution action of calcium hydroxide and being washed out by wind and rain, and to provide a durable concrete product that does not fade for a long period of time. Obtainable. Moreover, in addition to the effect of preventing discoloration by forming the above-mentioned high-density layer, the strength is improved, and the abrasion resistance, the frost damage resistance, and the
Improved chemical resistance, salt penetration resistance, etc.

[0018]

Example 1 First, prior to the examples, color pigments were prepared. FIG. 1 shows the color pigments. The color pigments 3 ′ are composed of natural crushed stone particles 4, color pigments 10, blast furnace slag particles 12 and cement particles 6. Color pigment 1
In No. 0, fine inorganic pigments were baked on the outer periphery of fine natural crushed stone, and the particle size was set to 10 to 50 μm.
As the blast furnace slag particles 12, powder having a particle size set to 10 μm or less was used. The color pigments are a mixture of natural crushed stone particles 4 having a particle diameter of 0.2 to 5 mm, color pigment 10, blast furnace slag particles 12 and cement particles 6. As the cement particles 6, those having a particle size of about 20 μm were used. That is, the color pigment 10, the natural crushed stone particles 4, the blast furnace slag particles 12, and the cement particles 6 are mixed by high speed rotation,
Due to the triboelectric charge generated, the colored pigment 10, the blast furnace slag particles 12 and the cement particles 6 were adsorbed and aggregated on the outer periphery of the natural crushed stone particles 4 and granulated to form colored pigments 3 '.

Next, a decorative mold using the above color pigments 3'was produced. That is, as the decorative form 1 as shown in FIG. 4, a frame made of a urethane foam resin having rigidity was used. This rigid foam urethane resin makeup frame 1
A foam layer was provided inside, and a dense integral skin layer was provided on the surface layer, and a 5 mm-thick adhesive layer 2 was formed on the surface by applying a water-soluble methyl cellulose adhesive. On the surface of the adhesive layer 2 of this decorative form 1, a large number of color pigments 3'prepared as described above were adhered by pressure spraying.

Next, the decorative formwork 1 was used to produce a concrete wall as an example product. That is, the mold material 7
6, a decorative mold 1 as shown in FIG. 6 is attached, and a concrete material 8 is placed between the mold 7 and another mold 7 ', and after curing and curing, the decorative mold 1 is fixed to the mold. It peeled with 7 (refer to FIG. 7). As a result, as shown in FIG. 3, in the concrete wall 9'on which the coloring pigments 3'are transferred and adhered, the coloring pigments 3'distributed in the surface layer are beautifully colored, and the surface thereof is In the layer, a high-density layer 14 made of calcium silicate hydrate or the like produced by the reaction of the blast furnace slag particles 12 and calcium hydroxide in the concrete material was formed, and the color durability was also very good.

[0021]

Example 2 In the same manner as in Example 1, color pigments were prepared prior to the examples. 2 shows the color pigments 3 ″. The color pigments 3 ″ are composed of the color pigment 11 made of the same material as the color pigment 10 of Example 1, blast furnace slag particles 12 and cement particles 6. And no crushed stone particles were used. The color pigments 3 ″ are obtained in Example 1
It was obtained by mixing the coloring pigment 11, the blast furnace slag particles 12 and the cement particles 6 at a high speed in the same manner as in.

Next, using the above-mentioned color pigments 3 ″, the above-mentioned color pigments 3 ″ were deposited and distributed in the same manner as in Example 1 on the same decorative form 1 (see FIG. 4) as that used in Example 1. Using this decorative formwork, a concrete wall was produced in the same manner as in Example 1. In the concrete wall 9'obtained in this way, the coloring pigments 3 "distributed in the surface layer are beautifully colored, and in the surface layer, Example 1
Similarly to the above, the high-density layer 14 made of calcium silicate hydrate or the like was formed, and the color durability was also very good.

The concrete walls 9'each of which was obtained in this manner were excellent not only in color durability but also in frost damage resistance, abrasion resistance, salt penetration resistance and chemical resistance. It had high strength.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of color pigments attached to blast furnace slag particles used in the present invention.

FIG. 2 is a schematic view showing another example of color pigments attached to blast furnace slag particles used in the present invention.

FIG. 3 is a schematic sectional view showing a concrete wall colored by the method of the present invention.

FIG. 4 is an explanatory view showing an embodiment of a makeup mold used in the present invention.

FIG. 5 is an explanatory diagram showing conventional color pigments.

FIG. 6 is an explanatory view showing a state in which a concrete material is filled in a mold provided with the decorative mold.

FIG. 7 is an explanatory view showing a state where the decorative formwork is peeled off from the concrete product.

FIG. 8 is an enlarged cross-sectional view of a surface layer of a conventional generated concrete wall.

[Explanation of symbols]

 3 ', 3 "Colored pigments 4 Crushed stone particles (natural crushed stone grains) 10,11 Colored pigments 12 Blast furnace slag particles

Claims (3)

[Claims] 1. A method of preparing a decorative formwork having a large number of colorants distributed on its surface, placing a concrete material with the surface as a contact surface, curing and curing, and then peeling off the decorative formwork. According to the method for coloring a concrete surface in which the coloring material is transferred to a surface layer of a concrete product, a coloring pigment and blast furnace slag powder are used as the coloring material, and a method for preventing discoloration of colored concrete. 2. The color pigments are obtained by adhering fine color pigment particles and fine cement particles to the outer periphery of crushed stone particles, and blast furnace slag particles are attached to the outer periphery of the crushed stone particles. Method for preventing discoloration of colored concrete. 3. The color pigments are obtained by adhering fine cement particles to the outer periphery of color pigment particles having a relatively large particle size, and the blast furnace slag particles are attached to the outer periphery of the color pigment particles. Item 1. A method for preventing discoloration of colored concrete according to Item 1.