KR101989511B1 - Aggregate exposed color precast concrete and manufacturing method thereof - Google Patents

Abstract

The present invention is, in concrete containing: cement; water; fine aggregate; coarse aggregate; pigments; and water reducing agent, precast concrete, which is aggregate exposed color precast concrete, characterized in that irregularities are formed on a concrete surface by using a surface retard sheet to a depth of 0.5 to 2.5 mm. According to the present invention, by using an aggregate exposure degree, it is possible to express an optimized texture, improve dispersibility of pigments to express a uniform color, and have excellent strength, thereby being suitable for use as a precast concrete exterior material.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an aggregate exposed color precast concrete,

The present invention relates to an aggregate-exposed color precast concrete and a method of manufacturing the same, and more particularly, to a method of manufacturing an aggregate-exposed color precast concrete by using a surface delay sheet to expose an aggregate on a concrete surface, The present invention relates to an aggregate exposed color precast concrete suitable for use as a precast concrete exterior material, and to a method for producing the same.

Generally, concrete is used for manufacturing various buildings and civil engineering structures by using cement, water, aggregate and the like. Concrete has been generally used as simple structural material due to gray monotony. In the past, the aesthetic effect of the structure was applied by applying paint on the exterior, or by expressing it as rock or steel panel or tile. Recently, however, Various methods have been proposed to produce aesthetic effects on the exterior of a structure without a finishing process. As one of the methods, a method of incorporating a pigment into the concrete composition itself has been proposed. In general, a method of adding various organic pigments or inorganic pigments to a concrete composition as a pigment to express various colors is mainly used.

However, when the general organic pigment or the inorganic pigment is applied to the concrete composition as described above, problems such as a decrease in the strength of concrete, a whitening phenomenon, and a discoloration due to inhomogeneity of pigment dispersion occur. Therefore, Is required to be developed and applied.

In addition, the aggregate is exposed to the concrete surface due to various building interior and exterior materials, and the demand for aesthetics and excellent texture is increasing, but the precast concrete suitable for this is insufficient.

Korean Patent Publication No. 2010-0072633

In order to solve the problems of the prior art as described above, the present invention uses a surface retardation sheet to expose an aggregate on a concrete surface to enable optimized texture expression, and to improve the dispersibility of the pigment, It is another object of the present invention to provide an aggregate exposed color precast concrete having excellent strength and suitable for use as a precast concrete exterior material, and a method for manufacturing the same.

These and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, water; Fine aggregate; Coarse aggregate; Pigments; And a water reducing agent, wherein the concrete is a precast concrete, and the surface delay sheet is used to form irregularities on the surface of the concrete at a depth of 0.5 to 2.5 mm, thereby providing an aggregate exposed color precast concrete .

The surface retardation sheet may be a monosaccharide; Polysaccharides; A compound having a carboxyl group; A compound having a hydroxyl group; Phosphoric acid or phosphate; And a hydrofluoric acid.

Wherein the concrete contains 30 to 60 parts by weight of water, 150 to 200 parts by weight of fine aggregate, 250 to 300 parts by weight of coarse aggregate, 1 to 10 parts by weight of pigment and 1 to 3 parts by weight of water reducing agent with respect to 100 parts by weight of the cement .

Also, the concrete may be coated with a surface strengthening agent containing alkoxysilanes, siloxane and ethanol on the surface of the concrete.

In addition, the present invention provides a concrete manufacturing method,

Attaching a surface delay sheet to the surface of the mold where the concrete is located; Placing the concrete in the mold and curing the concrete; Removing the cured concrete from the mold; And spraying the concrete surface, wherein the concrete is precast concrete, and irregularities are formed on the surface of the concrete to a depth of 0.5 to 2.5 mm, thereby providing an aggregate-exposed color precast concrete manufacturing method .

The step of curing the concrete is characterized by curing at atmospheric pressure vapor curing for 12 to 16 hours at a temperature of 20 to 55 占 폚.

The method of manufacturing the aggregate-exposed color precast concrete may further include applying a surface strengthening agent to the concrete surface.

According to the present invention, by controlling the degree of aggregate exposure using a surface retardation sheet, it is possible to form an uneven surface to provide an optimized texture expression, and the dispersibility of the pigment can be improved to exhibit uniform color, The present invention provides an aggregate exposed color precast concrete suitable for use as a precast concrete exterior material and a manufacturing method thereof.

1 is a photograph showing a precast concrete manufactured according to an embodiment of the present invention.
FIG. 2 is a photograph schematically showing a method of manufacturing aggregate-exposed precast concrete according to an embodiment of the present invention.
FIG. 3 is a flowchart briefly showing a method of manufacturing aggregate-exposed precast concrete according to an embodiment of the present invention.

Hereinafter, the aggregate-exposed color precast concrete of the present invention and a method of producing the same will be described in detail.

The aggregate exposed color precast concrete of the present invention is cement; water; Fine aggregate; Coarse aggregate; Pigments; And a water reducing agent, wherein the concrete is precast concrete, and a surface delay sheet is used to form irregularities at a depth of 0.5 to 2.5 mm on the concrete surface.

The surface retardation sheet may be a monosaccharide; Polysaccharides; A compound having a carboxyl group; A compound having a hydroxyl group; Phosphoric acid or phosphate; And a hydrofluoric acid.

The surface retardant may be present in an amount of from 30 to 40% by weight of the monosaccharide, from 0.1 to 10% by weight of the polysaccharide, from 8 to 12% by weight of the compound having a carboxyl group, from 35% To 40 wt%, phosphoric acid or phosphate 0.1 to 5.0 wt%, and hydrofluoric acid 0.1 to 5.0 wt%, and within this range, the texture of the aggregate and the uniform color tone can be expressed.

The monosaccharide may be selected from the group consisting of glucose, fructose, and galactose. In order to be suitable for precast concrete, glucose is preferably used.

The polysaccharide may be at least one selected from the group consisting of sucrose, loperol, dextrose, maltose, lactose, xylose, fructose, mannose, and glucose, In order to secure the exposure depth range, it is preferable to use sucrose.

Examples of the compound having a carboxyl group (-COOH) include at least one compound selected from the group consisting of carboxylic acid, malic acid, tartaric acid, citric acid, gluconic acid, heptagluconic acid and salts thereof (for example, sodium salt, potassium salt and calcium salt) Can be used.

The compound having a hydroxyl group (-OH) means a compound having a hydroxyl group (-OH) except for the above monosaccharide and polysaccharide. For example, it may be a compound having a hydroxyl group capable of retarding the curing of concrete used in the technical field of the present invention. Examples thereof include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2- Methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3- Diol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4- Aliphatic alcohols such as diol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, Diol; Alicyclic diols such as cyclohexane dimethanol, cyclohexanediol, hydrogenated bisphenol A and hydrogenated bisphenol F; Trimethylol ethane, trimethylol propane, hexitol, pentitol, glycerin, polyglycerin, pentaerythritol, dipentaerythritol, tetramethylol propane and the like.

The surface-retarding agent of the present invention may also be a surface-active agent such as calcium carbonate, silicon dioxide, sand, mica, talc, clay (such as kaolin), barium sulfate, sodium silicoaluminate, alumina, barium carbonate, dolomite Carbonates, CaMg (CO ₃ ) ₂ ), magnesium carbonate, magnesium oxide, and diatomaceous earth. In this case, 0 to 50% by weight and 0.1 to 50% by weight, based on the total weight of the surface retardant, can be included.

Preferably, the surface retardant is applied to the surface retardation sheet in an amount of 80 to 1,200 g / m < 2 > to penetrate the concrete at a penetration depth of 0.5 to 2.5 mm. This is because an application amount of less than 80 g / The amount of retardant applied and the depth of penetration are so small that the hardening of the mortar is excessively performed and the mortar separation and separation at the surface portion due to the high pressure water is not performed and the aggregate is not exposed.

On the other hand, when the application amount exceeds 1200 g / m < 2 > and the penetration depth exceeds 2.5 mm, the application amount of the retarder and the depth of penetration are excessively excessive and hardening of the mortar is weak, Resulting in defective product in the molding block.

The concrete of the present invention is cement; water; Fine aggregate; Coarse aggregate; Pigments; And a water reducing agent, wherein 30 to 60 parts by weight of water, 150 to 200 parts by weight of a fine aggregate, 250 to 300 parts by weight of a coarse aggregate, 1 to 10 parts by weight of a pigment and 1 to 3 parts by weight of a water reducing agent are added to 100 parts by weight of the cement .

Specifically, the concrete may be contained in an amount of 35 to 45 parts by weight of water, 170 to 190 parts by weight of fine aggregate, 250 to 270 parts by weight of coarse aggregate, 3 to 7 parts by weight of pigment, and 1 to 3 parts by weight of water reducing agent based on 100 parts by weight of the cement And has an effect of exhibiting a compressive strength suitable as a concrete sheathing material within this range.

The concrete may comprise a binder, for example cement and optionally an admixture. On the other hand, as the admixture, fly ash, blast furnace slag fine powder or a mixture thereof can be used.

The cement of the present invention may be cement which is generally used in the field to which the present invention belongs. For example, the powder cement used for cement mortar includes white cement, Portland cement, blast furnace slag cement, , And a mixture thereof.

Specifically, the cement powder is also not more than 4,500 and 5,500㎠ / g, 0.6% total alkali amount (Na2Oeq), having a diameter of less than 45㎛, SO ₃ content of 3.0 to 3.6wt% of the used cement Is preferable in terms of the compressive strength of the precast concrete.

Particularly, it is preferable that the cement has a powderity of 4,500-5,500 cm2 / g. Within this range, it is possible to secure a performance suitable for expressing early strength for premature demolding of formwork required in the field. In the case where the powdery degree is higher than the above range, a high early strength can be obtained, but a separate facility for obtaining such a powdery degree and an additional step are required, which is not economical, It is difficult to secure the early strength of the level.

The concrete composition has a water-binding material ratio (W / B) of 30 to 50 wt%, a fine aggregate material ratio of 30 to 45 vol%, and an appropriate physical property as a concrete exterior material can be exhibited within this range.

The water-binding material ratio (W / B) is a numerical value that determines the strength and durability of concrete such as design standard strength and compounding strength. In the present invention, the water-binding material ratio of 35 to 45 wt% .

(S / a) is a volume ratio of the fine aggregate S to the total aggregate (fine aggregate + coarse aggregate: a) volume, and is a value that determines the fluidity of the concrete. In the present invention, the aggregate percentage is 37 to 42 vol% The present invention is preferable to achieve the desired effect.

In the present invention, the aggregate is divided into a fine aggregate and a coarse aggregate. The aggregate having a particle size of 5 mm or less is referred to as a fine aggregate, and the aggregate having a particle size larger than 5 mm is classified as a coarse aggregate.

The pigments in the present invention are used to develop color in the colored concrete composition. Such pigments may be iron oxide as the reddish brown pigment, iron hydroxide as the yellow pigment, chromium oxide as the green pigment, sodium aluminosilicate as the blue pigment, and titanium oxide as the white pigment.

In addition, the concrete of the present invention can improve the durability, weatherability and abrasion resistance of concrete by applying a surface strengthening agent to the surface of the concrete.

Specifically, when the surface of the concrete is sprayed with water and the state of moisture on the surface is ascertained, a coating layer is formed on the surface of the concrete by spraying or applying a surface strengthening agent to improve the durability, weatherability and abrasion resistance of the concrete It is.

The surface strengthening agent of the present invention may include alkoxysilanes, siloxane, ethanol and water.

The surface strengthening agent is present in an amount of from 10 to 30% by weight of Alkoxysilanes, from 10 to 30% by weight of Siloxane, from 3 to 10% by weight of Ethanol and from 30 to 30% 70% by weight, and the durability, weatherability, and abrasion resistance of the concrete are improved within this range.

The surface strengthening agent may be selected from the group consisting of methylacrylate, ethylacrylate, butylacrylate, 2- (2-hydroxyethyl) butyrate, and the like, based on 100 parts by weight of the alkoxysilane, siloxane, 180 to 220 parts by weight of an acrylic monomer containing at least one of ethylhexyl acrylate (2-ethylhexylacrylate), cyclohexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and octyl methacrylate, 180 to 220 parts by weight of a functional monomer containing at least one of glycidylmethacrylate, glycidyl methallyl ether and 3,4-epoxycyclohexylmethacrylate; Ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, indaconic acid and crotonic acid; Olefinic monomers such as ethylene; And 30 to 50 parts by weight of a copolymerizable monomer containing at least one of styrene-based monomers such as styrene, -methylstyrene, and vinyltoluene.

The concrete of the present invention has a unit cement amount of 350 to 450 kg / m 3; Slump flow value 450 ± 50 mm; And an air amount of 3 to 6 vol%; Under compressive strength of 40 MPa or more and 40 to 45 MPa within 3 days of curing at room temperature.

In another example, the concrete has a unit cement amount of 350 to 450 kg / m 3; Slump flow value 450 ± 50 mm; And an air amount of 3 to 6 vol%; Under compressive strength of 48 MPa or more and 48 ~ 55 MPa within 7 days of age at room temperature curing.

As another example, the concrete has a unit cement amount of 350 to 450 kg / m 3; Slump flow value 450 ± 50 mm; And an air amount of 3 to 6 vol%; , The compressive strength is 44 MPa or more and 44 ~ 47 MPa within 1 day of aging and the compressive strength is more than 50 MPa and 52 ~ 57 MPa within 7 days of age.

The aggregate is exposed on the surface of the precast concrete of the present invention at a size of 0.5 to 2 mm.

Specifically, the precast concrete has an exposed depth of aggregate of 0.5 to 1.7 mm to form irregularities on the surface of the concrete, thereby providing an excellent texture expression.

The method of producing aggregate exposed precast concrete of the present invention comprises the steps of: attaching a surface delay sheet to the surface of a mold where concrete is to be placed; Placing the concrete in the mold and curing the concrete; Removing the cured concrete from the mold; And spraying the concrete surface, wherein the concrete is precast concrete, and the concave and convex portions are formed on the surface of the concrete to a depth of 0.5 to 2.5 mm.

The step of curing the concrete can be cured by atmospheric vapor curing at a temperature of 40 to 60 DEG C for 12 to 16 hours.

In the present invention, the atmospheric pressure steam curing method is used to increase the production efficiency of the concrete product, and the curing method can be appropriately changed and applied according to the working environment or the manufacturing efficiency.

Specifically, when the temperature falls below 40 ° C, the curing process through the steam may not be smooth. If the temperature exceeds 60 ° C, the hydration of the cement is promoted and the hydrate on the surface of the cement particles is dense. It is most preferable that the strength is maintained at a temperature not exceeding 60 DEG C because the progress is disturbed to increase the strength in a short time but the strength elongation rate decreases with time.

Accordingly, the surface layer portion of the concrete in which the surface retardant sheet inner surface retardant penetrates is not cured by the surface retardant impregnated for a certain period of time during which the curing is performed, whereas the base layer portion in which the surface retardant is not cured is cured The surface layer forming the surface layer of the base layer is relatively low in strength as compared with the base layer so that the aggregate can be exposed by the impact energy due to the injection of high pressure water.

The step of spraying the surface of the concrete according to the present invention comprises spraying high-pressure water of a certain strength onto the surface portion of the upper surface of the cured concrete after curing to form a surface layer of uncured cement mortar Pressure water, and exposing only the aggregate adhered to the cement mortar of the base layer, which is cured so that the surface retarder is not penetrated and the strength is developed, to the outside.

The spraying is preferably carried out using a high pressure washer at a pressure ranging from 120 to 170 kgf / cm 2 of high pressure water sprayed through a high pressure washer. This is because when the injection pressure is less than 120 kgf / cm 2, the uncured surface layer cement mortar If the pressure is higher than 170 kgf / cm 2, the surface layer aggregate may fall off.

The step of removing the hardened concrete of the present invention from the mold means a step of demolding the concrete in the mold.

Since color concrete is a supply product compared to general concrete, it is advantageous to make the demolding strength higher than general precast concrete because it is necessary to minimize the damage of the member during demoulding. In order to maintain the strength of the product in such a state, the curing condition may be satisfied. The appropriate deformation strength of the member should be maintained at a minimum of 15 to 18 MPa.

The method for producing precast concrete for aggregate exposure of the present invention may further comprise the step of applying a surface strengthening agent to the surface of the concrete.

Also, the present invention provides a concrete exterior material comprising the aggregate exposed precast concrete produced by the method of manufacturing the aggregate exposed precast concrete.

The concrete exterior material of the present invention is characterized in that the exposed depth of the aggregate is 0.5 to 2 mm. Specifically, the concrete exterior material preferably has an exposure depth of 0.5 to 1.7 mm in terms of texture.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

[Example]

Example 1

After attaching the surface retardant paper to the interior of the formwork to be exposed to the aggregate, colored concrete blended according to Table 1 below was placed in the formwork. Thereafter, the colored concrete was vapor-cured, the next day the form was dismantled, the surface delay paper was removed, and the surface was sprayed on the surface using a high-pressure washer.

After the surface of the colored concrete was sufficiently dried, the surface reinforcing agent was applied to produce an aggregate exposed precast colored concrete.

Example 2

Except for the fact that the curing at room temperature was carried out in place of the steam curing in Example 1, aggregate exposed precast colored concrete was prepared in the same manner as in Example 1.

W / B
(%) S / a
(%) Unit Weight (kg / ㎥) AD
(B *%) W C Pigment CS G ₁₉ 40.0 41.0 160 400 20 750 1,060 2.4

W / B: water-binding ratio S / a: fine aggregate ratio

W: Unit quantity

C: Three kinds of cement

CS: Fine aggregate

G ₁₉ : Coarse aggregate

AD: water reducing agent

[Test Example]

The compressive strength development characteristics of the precast colored concrete prepared in the above Examples were measured by the following methods, and the results are shown in Table 2 below.

How to measure

Concrete specimens were prepared in accordance with KS F 2403 "Method of specimen preparation for concrete strength test" and compressive strength was measured by KS F 2405 "Concrete compressive strength test method".

Slump
Flow
(mm) Air
(%) Example 1
Steam curing
Compressive strength (MPa) Example 2
(Room temperature curing
Compressive strength MPa) 1 day 7 days 3 days 7 days 450 4.2 45.4 54.8 42.3 49.5

As shown in Table 2, in the case of Example 1 in which steam curing was performed, it was confirmed that the compression strength was 54.8 MPa after 7 days, which is the most excellent.

[Reference Example]

Various colored concrete were prepared in the same manner as in Example 1, except that the content of the pigment was changed to 1 wt%, 3 wt%, 5 wt% and 10 wt%, respectively, as shown in FIG.

As a result, it has been confirmed that the precast colored concrete according to the present invention can form a uniform color while forming the uneven surface.

Claims (7)

cement; water; Fine aggregate; Coarse aggregate; Pigments; And a water reducing agent,
The concrete is precast concrete, which is formed by using a surface retardation sheet to form irregularities at a depth of 0.5 to 2.5 mm on the concrete surface.
Wherein the surface retardation sheet comprises 30 to 40% by weight of a monosaccharide, 0.1 to 10% by weight of a polysaccharide, 8 to 12% by weight of a carboxyl group-containing compound, 35 to 40% by weight of a compound having a hydroxyl group, And 0.1 to 5.0% by weight of hydrofluoric acid is a surface retardation sheet applied in an amount of 80 to 1,200 g / m < 2 >. delete The method according to claim 1,
The concrete is contained in an amount of 30 to 60 parts by weight of water, 150 to 200 parts by weight of water, 250 to 300 parts by weight of coarse aggregate, 1 to 10 parts by weight of pigment and 1 to 3 parts by weight of water reducing agent based on 100 parts by weight of the cement Features pre-painted concrete precast concrete with aggregate. The method according to claim 1,
Wherein the concrete is coated on the surface of the concrete with a surface strengthening agent containing alkoxysilanes, siloxane and ethanol. In a concrete manufacturing method,
Attaching a surface delay sheet to the surface of the mold where the concrete is located;
Placing the concrete in the mold and curing the concrete;
Removing the cured concrete from the mold; And
Spraying the concrete surface,
The concrete is precast concrete, and the concrete surface is formed with irregularities at a depth of 0.5 to 2.5 mm,
Wherein the surface delay sheet comprises 30 to 40% by weight of monosaccharide, 0.1 to 10% by weight of polysaccharide, 8 to 12% by weight of a compound having a carboxyl group, 35 to 40% by weight of a compound having a hydroxyl group, And 0.1 to 5.0% by weight of the hydrofluoric acid is a surface retardation sheet applied in an amount of 80 to 1,200 g / m < 2 >
Wherein the step of curing the concrete is cured by atmospheric vapor curing at a temperature of 40 to 60 DEG C for 12 to 16 hours. delete 6. The method of claim 5,
The method of claim 1, wherein the method further comprises applying a surface strengthening agent to the surface of the concrete.

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