KR100895214B1 - Color Cement Composition for Roadway Pavement and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to a method for producing color cement and a composition for producing colored concrete for driveway. The present invention, in the color cement composition for the production of driveway color concrete, 30 to 80% by weight of Portland cement, 5 to 60% by weight of blast furnace slag, 1 to 25% by weight of fly ash or silica fume, 1 to Ⅱ anhydrous gypsum 1 ~ It provides a driveway color cement composition comprising 7% by weight and 2-10% by weight of an inorganic pigment. According to the present invention, it is possible to produce a roadway colored concrete excellent in durability and strength and excellent visibility.

Bus lanes, colored, color, inorganic pigments, pigment, iron oxide, concrete, cement, slag powder, fly ash, silica fume, anhydrous gypsum, color cement

Description

Color Cement Composition for Roadway Pavement and Manufacturing Method Thereof}

The present invention relates to a method for producing color cement and a composition for producing colored concrete for driveway.

Driveway packaging materials such as bus lanes are conventionally colored asphalt and color semi-rigid packaging. Color asphalt is easily discolored and worn due to the low strength and durability of the colorless asphalt binder, and in the summer, it is necessary to frequent maintenance due to the rutting caused by the load of the vehicle, and when the surface is wet due to the slip resistance of the color coating material. The longer the braking distance, the greater the risk of accidents by sliding.

In addition, the color semi-rigid packaging has a disadvantage that the cement paste is dropped due to the low adhesion between the asphalt and the cement by injecting cement paste, which is a material different from the asphalt, to the porous asphalt pavement, and has a low slip resistance due to the smooth surface.

Concrete pavement is used for high-quality roads such as highways because of its excellent rigidity and durability. However, in some areas, alkali-aggregate reactions are caused by the use of reactive aggregates and snow removal agents such as sodium chloride, causing cracks and breakage. In addition, the alkali and chloride ions contained in the snow remover dissolve calcium hydroxide (Ca (OH) ₂ ) in the cement hydrate to form fine pores in the tissue so that water or harmful substances can easily penetrate the inside from freezing and thawing. Erosion is intensified, and reinforced concrete pavement causes reinforcing corrosion due to the penetration of chloride ions, causing cracks and breakage of concrete. In addition, alkali ions, alkali sulfates and calcium hydroxides in cement are easily dissolved in water and elute on the concrete surface with bleeding or evaporation of water, causing whitening and causing white stains or discoloration on the colored concrete surface.

On the other hand, some organic pigments used in asphalt or concrete have a problem in that visibility is degraded over the period of use due to decomposition by ultraviolet light causes discoloration.

In this patent application No. 1988-0006211, the color cement composition introduces a color cement manufacturing technology which is prepared by mixing water and general pigments containing sand, silica sand, and alum, but including sand and dolomite powder. The mixed cement will be difficult to manufacture and use, and its use is also unclear. Patent Application No. 1994-0017919 The method and composition for preparing far infrared ceramic color cement introduces a technique for producing cement by mixing far-infrared ceramic powder, gypsum powder and calcium carbonate powder, but the gypsum content is 30-70%, calcium carbonate Since 10% to 20% of the cement may be manufactured, it is difficult to use for producing concrete for structures due to problems of hydration, strength expression, and durability of cement, and its use and effects are unclear. Patent Application No. 1999-0044427 Color Waterproof Cement introduces color waterproof cement for surface finishing of structures, but it is not suitable for the manufacture of concrete for road paving.

Regarding the color concrete pavement, the method of spraying cement mixture and color polymer mixture on the porous asphalt pavement is introduced in the color road pavement method of Patent Registration No. 0520964-000, but this is an asphalt pavement method, This method is different from color cement concrete pavement such as rigidity, durability, and wear resistance. Patent Application No. 2004-0088108 Color cement mortar for the background finishing of concrete structures forms a color mortar layer on the concrete surface, which is applied to road pavement due to the problem of deterioration of slip resistance, discoloration and damage by wear and peeling. This is difficult. Patent registration No. 0135100-000 Color coating method of permeable concrete and color coating material used therein, Patent registration 0035315-0000 Color permeability concrete, Patent registration No. 0248478-0000 Fiber reinforced color permeable concrete, Patent registration 0132371-0000 Permeable Concrete, Patent Application No. 1998-0068367 Permeable Color Concrete Pavement Construction Method, Patent Registration No. 0510318-0000 Color Permeable Concrete Using Two Types of Recycled Aggregate and Its Manufacturing Method, Patent Application No. 1998-0082105 Patent registration 0240140-0000 Color-permeable concrete road paving method is a method for manufacturing and constructing color-permeable concrete without the provision of cement. Patent Registration No. 0471989-0000 The road paving method and road paving material with semi-rigidity and water retention have different technical fields from the color paving method of injecting cement paste into porous asphalt or concrete paving using color cement. There is no specific mention.

As a manufacturing method of the color concrete, Patent registration No. 686254 White color concrete composition comprising titanium dioxide-metakaline-based white pigment, Patent registration No. 588192 White color concrete composition, Patent registration No. 588191 Black color concrete composition, Patent registration No. 057970 Durable white color concrete composition, patent application 1993-7847 There is a method for producing color concrete, but this relates to a concrete manufacturing method, which is different from the technical idea of the present patent, the application is unclear. In addition, when the pigment is added in the concrete manufacturing step without using the mixed color cement, the dispersion or mixing of the pigment may not be a problem in the case of good fluidity, but when the slump is low, such as road paving concrete, the concrete There is a problem that the mixing time is greatly increased, or the dispersion of the pigment is not sufficient, resulting in uneven coloration and vividness.

Therefore, it is a colored paving material for roadways such as bus lanes, and has excellent strength, durability, and chemical resistance, and can be easily used in the production of color concrete on the site like concrete manufacturing method for general road pavement without whitening or discoloration by UV rays. Development of color cement is required.

 An object of the present invention is to provide a high-strength, high-durability color cement composition for a roadway and a method of manufacturing the same that improve the composition of the cement in order to solve the above problems.

In order to achieve the above object, the present invention uses inorganic powder iron oxide pigment of fine powder higher than cement particles in an appropriate range, so that the visibility required for roads such as bus-only vehicles can be avoided without problems of discoloration due to ultraviolet rays and chemicals. An attempt was made to produce excellent color cement for colored concrete.

In the case of bus lanes, high-strength concrete is required because the load by the vehicle is higher than that of general passenger cars. To this end, particles were used as fine inorganic pigments compared with cement, and high strength color cement having excellent strength expression and durability was selected by selecting and applying an appropriate amount of additive having excellent visibility and no problem in strength and durability.

In addition, high-durability concrete is added by adding slag powder, fly ash or pozzolanic material of fly ash or silica fume to prevent discoloration by whitening of concrete, erosion by snow melting and freeze-thawing, and damage by alkali-aggregate reaction, and to increase the clearness. To manufacture a highly durable cement that can be prepared. On the other hand, in the case of road pavement concrete, the thickness of the concrete and the area are wider than general structures, so it is difficult to cure curing. When a large amount of slag powder and fly ash, which are lower in hydration rate than cement, are mixed, the condensation and hardening are delayed. There is a problem to maintain and cure care, there is a problem that the dry shrinkage is increased when the fine powder inorganic pigment and slag fine powder is added.

As a result of researches to solve these problems, the use of anhydrous gypsum as a hydration reaction accelerator in accordance with the composition of cement and the mixture to accelerate the cement coagulation and hardening, to form a compact hydrate structure, to reduce the cracks caused by dry shrinkage I knew I could. By this effect, the penetration of harmful chlorine ions into the concrete is also significantly lowered, thereby reducing discoloration of the colored concrete by whitening by reducing the migration of the whitening product. By using these characteristics, it was intended to produce high strength, high durability color cement.

In order to achieve the above technical problem, the present invention, in the color cement composition for the production of color concrete for roadway, Portland cement 30 to 80% by weight, blast furnace slag 5 to 60% by weight, fly ash or silica fume 1 to 25 The present invention provides a color cement composition for driveway comprising 1% by weight to 7% by weight of Type II anhydrous gypsum and 2 to 10% by weight of an inorganic pigment.

In addition, the present invention, the inorganic pigment is iron oxide (Fe ₂ O ₃ ), lead chromate (PbCrO ₄ ), lead molybdate (PbMoO ₄ ), cadmium red (Cd (S _x Se _1-x )), lead tetraoxide (Pb ₃ O ₄ ), yellow iron oxide (FeOOH), lead chromate (PbCrO ₄ ), chrome green, ultramarine blue (Na _8-10 Al ₆ Si ₆ O ₂₄ S _2-4 ), blue (Fe ₇ (CN) ₁₈ (H ₂ O ) _x , X = 14-16), at least one material selected from the group consisting of black iron oxide (Fe ₂ O ₃ ), carbon black (C) and titanium dioxide (TiO ₂ ).

In another aspect, the present invention provides a method for producing a color cement composition for a driveway, characterized in that the composition of claim 1 is added to a high-efficiency powder mixer and stirred for 2 to 10 minutes.

According to the present invention, it is possible to provide a high strength, high durability color cement composition for roadway. In addition, the present invention uses fine powder inorganic iron oxide pigment having a higher powder than cement particles in an appropriate range, thereby making it possible to manufacture colored concrete having excellent visibility required for driveway without the problem of discoloration caused by ultraviolet rays and chemicals. According to the present invention, slag fine powder, fly ash or pozzolanic material of silica fume is added to prevent discoloration due to whitening of concrete, erosion by snow melting and freeze-thawing, and damage due to alkali-aggregate reaction and increase in color. It is possible to produce high durability cement which can manufacture this high concrete.

Hereinafter, the present invention will be described in detail by describing the characteristics and embodiments of the present invention with reference to the accompanying drawings.

The driveway color cement composition of the present invention comprises portland cement, slag powder, fly ash or pozzolanic material of silica fume, and anhydrous gypsum.

In the present invention, the content of the portland cement in the color cement composition is preferably 30 to 80% by weight. The proportion of cement is determined by the minimum and maximum addition rates of inorganic pigments, slag powders and pozzolanic materials of fly ash or silica fume. Portland cement expresses strength by condensation and curing by its own hydration reaction, and controls the setting time, curing speed and strength of the cured product by supplying the stimulant necessary for the hydration reaction of slag powder and the alkali component necessary for the pozzolanic reaction of pozzolanic materials. do. When the amount of Portland cement is small, the condensation is delayed and the working time is delayed for the surface finishing and joint cutting when paving the concrete road, the strength is delayed and the long-term curing management is required, and the hydration of slag fine powder and pozzolan material is sufficiently There is a disadvantage that can not be achieved. In addition, when the amount of Portland cement is large, the heat of hydration increases, causing cracks due to heat of hydration and dry shrinkage, thereby degrading concrete performance.

In the case of color concrete pavement, the aesthetics and visibility of the surface are important factors, and when whitening occurs during the hydration of cement, the coloring effect is reduced. Whitening is divided into 1st and 2nd whitening, and it is a phenomenon that occurs immediately after concrete pouring and between early ages. Soluble component of cement dissolved in mixed water is transported along with the branding water to the plastering surface and precipitated on the surface of concrete casting. It is called primary whitening. Examples of the primary bleaching agent include potassium sulfate (K ₂ SO ₄ ) and sodium sulfate (Na ₂ SO ₄ ) formed by potassium and sodium ions contained in cement and sodium carbonate (Na ₂₎ Calcium hydroxide produced by formulas ① through ③ during the hydration of alkali metal compounds such as CO ₃ ), potassium carbonate (K ₂ CO ₃ ), and cement minerals Alite (3CaO · SiO ₂ ) and Belite (2CaO · SiO ₂ ) There is calcium carbonate (CaCO ₃ ) formed by (Ca (OH) ₂ ) reacting with carbon dioxide in the air.

① CaO + H ₂ O → Ca (OH) ₂

_{② 2 (3CaO · SiO 2)} + 6H 2 O → CaO · SiO 2 · H 2 O + 3Ca (OH) 2

③ 2 (2CaO · SiO ₂ ) + 4H ₂ O → CaO · SiO ₂ · H ₂ O + 3Ca (OH) ₂

④ Ca (OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O

⑤ 2NaOH (or 2KOH) + CO ₂ → Na ₂ CO ₃ (K ₂ CO ₃ ) + H ₂ O

Secondary bleaching is a phenomenon that occurs in old concrete structures, in which rainwater and groundwater invade into the dried hardened body, whereby soluble components in concrete or reaction products of soluble components and infiltration components are transported to the surface and precipitated. In this case, not only damage the aesthetics of the structure but also mean that the durability of the structure is weakened, so it must be handled with care.

As the material showing the secondary bleaching phenomenon, in addition to the material showing the first bleaching phenomenon, the following chemical reaction is caused by the penetration of acidic water produced by dissolving acidic components in the air, such as SO ₂ and CO ₂ in rainwater. Accordingly, calcium carbonate or calcium sulfate may be formed, or calcium chloride used as a snow melting material, sodium chloride, and a soluble component of cement react to form a whitening material.

⑥ H ₂ O + SO ₂ + 1 / 2O ₂ → H ₂ SO ₄

_{⑦ Ca (OH) 2 + H} 2 SO 4 → CaSO 4 · H 2 O

⑧ H ₂ O + CO ₂ → H ₂ CO ₃

⑨ CaCO ₃ + H ₂ CO ₃ → Ca (HCO ₃ ) ₂

⑩ Ca (HCO ₃ ) ₂ + Ca (OH) ₂ → ₂ CaCO ₃ + 2H ₂ O

The amount of Portland cement should be determined in consideration of the above matters.When the amount of Portland cement is higher than 80% by weight, the effect of reducing heat of hydration, improvement of durability and reduction of whitening by slag powder and pozzolanic material is less. If it is lower than%, the amount of calcium hydroxide (Ca (OH) ₂ ) required for the reaction of the slag fine powder and the pozzolanic material is small, resulting in low strength expression and durability, and excessive condensation delay occurs, thereby delaying the entire work process. . Therefore, the amount of Portland cement should be 40 to 80% by weight in consideration of the reaction characteristics according to the amount and mixing ratio of other materials.

In the present invention, the amount of the inorganic iron oxide pigment used in the color cement production should be determined in a range that does not adversely affect the strength and durability of the concrete while ensuring the clarity of the bus lane, the color cement composition described above to 100 parts by weight When doing, it is preferable to use 2-10 weight part.

Pigments can be broadly divided into inorganic and organic pigments according to the ingredients of the raw materials. Organic pigments have better color clarity than inorganic pigments, but discoloration and decomposition due to ultraviolet rays, heat, and organic solvents occur, and they are exposed to various weather reactions, chemicals, and oils. Not suitable for use as a pigment. In contrast, inorganic pigments are excellent in durability and can maintain color for a long time, and fine inorganic pigment particles fill the pores in concrete to increase the strength, thereby extending the life of road paving.

Inorganic pigments are metal-based pigments, depending on their chemical composition: Oxide, Hydroxide, Sulfate, Chromate, Carbonate, Sulfide, Silicate Etc.

In the production of concrete cement for concrete pavement for bus lanes, various colors of pigments such as white, black, yellow, red, blue and green can be used depending on the desired color.In consideration of visibility, economical efficiency and durability, pigments of appropriate color and composition Should be selected.

The production of color cement for paving red concrete pavement includes iron oxide (Fe2O3), lead chromate (PbCrO4), lead molybdate (PbMoO4), cadmium red (Cd (S _x Se _1-x )), podium (trioxide tetraoxide, Pb ₃ O). ₄ ) and the like, and it is preferable to use an iron oxide (Fe ₂ O ₃ ) pigment which is excellent in colorability, hiding power, weather resistance and low cost, and has excellent economic efficiency.

In the production of yellow concrete pavement color cement, a pigment containing yellow iron oxide (FeOOH) or lead chromate (PbCrO ₄ ) as a main component may be used. However, it is preferable to use yellow iron oxide (FeOOH) having excellent light resistance and chemical resistance.

As green concrete paving pigments, pigments such as chrome green, which are produced by mixing sulfur lead and sensitizing, and pigments such as ultramarine blue and navy blue, are used as pigments for blue concrete paving.

In addition, for black concrete pavement such as asphalt, it is preferable to prepare cement by adding black iron oxide (Fe ₂ O ₃ ) or carbon black (C).

White pigments may be manufactured using white pigments such as titanium dioxide (TiO ₂ ), zinc oxide (ZnO), zinc sulfide (ZnS), and barium sulfate (BaSO ₄ ), but white is not much different from the existing concrete pavement. In addition, since the reflectance of light is large and may cause eye fatigue, it is not suitable as a pigment for concrete pavement for buses.

Color cement is changed according to the type and content of inorganic pigments used, the color of cement and concrete is changed, each value can be measured through the measurement by the L * a * b * colorimeter.

Here, L is a value expressed in the range of 0 to 100, indicating brightness, a indicates that red increases when a positive value is increased, and green increases when a negative value is increased, and b is a positive value. If the value is increased, yellow is increased, and if it is increased to a negative value, the blue color is increased. The values of L *, a *, and b * change according to the type and color of the pigment. As the color gets darker, the visibility increases.

However, since the pigment is present only as fine particles without reactivity with cement, when the amount of use is excessively increased, the fluidity of the concrete decreases, thereby increasing the number of units. Therefore, the strength and water-tightness of the concrete deteriorate and the durability deteriorates. There is this.

Therefore, the addition rate of the pigment is preferably within the range of 2 to 10% by weight, which can secure visibility of bus lanes but does not have a problem of deterioration in strength and durability. Filling tends to increase the strength of concrete.

In the present invention, the content of slag powder in the color cement composition is preferably 5 to 60% by weight.

Slag fine powder is a latent hydraulic material that is quenched by a crushing facility, and then crushed into fine powder to easily react with cement. In itself, it is hardly cured but contains gypsum (CaSO _4). ), Calcium hydroxide (Ca (OH) ₂ ), potassium hydroxide (KOH), sodium hydroxide produced by SO ₄ ^{2 -} ions eluting from potassium sulfate (K ₂ SO ₄ ) and sodium sulfate (Na ₂ SO ₄ ) or cement hydration When stimulated by OH ^- ions eluted from (NaOH) or the like, an alkaline component is supplied from itself to cause a hydration reaction. When the slag powder is added to the cement, the production of dense CSH hydrate is increased compared to the hydration of cement alone, and the production of chemically and physically weak calcium hydroxide (Ca (OH) ₂ ) and alkali salts is reduced, thereby reducing the strength of concrete, Watertightness, chemical resistance and durability are increased.

In addition, when the aggregate used for concrete pavement has alkali-aggregate reactivity, alkali in cement increases or alkali ions dissolved from alkali salts such as sodium chloride (NaCl) and potassium chloride (KCl) used as a snow removing agent penetrate into the concrete. Alkali-silica gel is formed by the reaction between the cooling and the cooling, and when the material absorbs water, the expansion causes cracking and breakage of the concrete.

Expression ^{⑪ Si-OH + Na + +} OH - → Si-O-Na + + H 2 O

Si-O-Si + 2NaOH → Si-O_Na ⁺ + Na ⁺ O ^-- Si + H ₂ O

However, slag powder has less alkali than that of cement, and when it is added to cement, the amount of alkali in cement decreases, and because it forms a dense hydrate, the watertightness increases and the amount of alkali penetrating from the snow removing agent decreases alkali-aggregate reaction. The effect can be obtained.

When Cl ^- ions dissolved from chlorides such as sodium chloride (NaCl) and calcium chloride (CaCl ₂ ) used as a snow removing agent penetrate into concrete, they react with Ca (OH) ₂ , a hydration product of cement, to react with CaO · CaCl ₂ · 2H ₂ O to produce a crystal or by the reaction of formula ⑬ Cl ^- ions in cement hydrate Et Lin ZUID is let this reaction is substituted and SO ₄ in the cement hydrate is destroyed, causing the concrete strength and durability decrease.

3CaOAl ₂ O ₃ 3CaSO ₄ 32H ₂ O + 3CaCl ₂ = 3CaOAl ₂ O ₃ 3CaCl ₂ 32 H ₂ O + 3CaSO ₄

However, adding an appropriate amount of slag powder and gypsum (CaSO ₄ ) to cement promotes the formation of ethrinzite and improves the penetration resistance of chloride ions by filling the pores of concrete with a large amount of ethrinite. Reduces the strength and durability degradation of concrete caused by chloride ions.

However, when the amount of the slag powder is excessively increased to 60% by weight or more, the amount of cement that stimulates the hydration of the slag powder is reduced, thus causing the condensation and curing of concrete to be delayed and the work process is lengthened. In addition, in the case of road pavement difficult to sufficiently wet curing for a long time there is a problem that the strength is reduced because the cement is not sufficiently hydrated. Therefore, it is appropriate to adjust the amount of the slag powder used in the range of 10 to 60% by weight.

In the present invention, the content of anhydrous gypsum is preferably 1 to 7% by weight.

Gypsum acts to have sufficient working time by delaying condensation by inhibiting hydration of calcium aluminate phase (C ₃ A) and ferrite phase (C ₄ AF) minerals contained in cement early in the hydration of cement. On the other hand, gypsum not only inhibits the hydration of cement but also promotes the hydration of cement calcium silicate phases (C ₃ S and C ₂ S), which greatly contributes to the strength development of cement and concrete. In particular, by promoting the hydration of the fine slag powder, there is an effect of preventing the condensation delay and initial strength decrease, which is a disadvantage of the cement mixture. Therefore, the concrete road paving can shorten the curing time required for joint cutting after the concrete is laid, and the construction period can be shortened by shortening the curing management order.

However, if the gypsum remains after hardening of cement or concrete due to the excessive content of anhydrous gypsum, it reacts with C ₃ A, C ₄ AF, or monosulfate, a hydrate that does not react at first, thereby producing edrinzite, an expandable hydrate. There is a problem that the structure is damaged by cracking and breaking. Therefore, the amount of gypsum is 1 to 7% by weight so that anhydrous gypsum can be sufficiently consumed within 3 to 7 days in consideration of the amount of C ₃ A and C ₄ AF minerals in the cement used, the amount of cement and the amount and powder of slag powder. It is preferable to adjust in the range.

In the present invention, the pozzolanic material is a fine powder mineral material composed mainly of amorphous silica or silicate, and is a material that reacts with calcium hydroxide (Ca (OH) ₂ ) produced by cement hydration to form CSH. Representative pozzolanic materials are fly ash and silica fume, and the appropriate amount of the color cement composition is 1 to 25% by weight.

If the heat of hydration is large during condensation and hardening during concrete pavement, the temperature of concrete increases and the temperature difference between the top and bottom increases, and the evaporation rate of water increases, so that cracks due to heat of hydration and cracks due to plastic shrinkage increase.

The pozzolanic material reacts slowly with calcium hydroxide (Ca (OH) ₂ ) produced during the hydration of C ₃ S and C ₂ S in cement to form CSH with excellent strength, water tightness, chemical resistance and durability. This reaction is slower than the hydration of cement, the amount of heat of hydration is low, and the rate of temperature rise and temperature of the concrete is small, which is effective in reducing the cracks due to the heat of hydration and water evaporation of the concrete surface, and to improve the long-term strength and durability of concrete pavement. It is an effective material.

Pozzolan materials, like slag powder, lower the alkali content in concrete and consume calcium hydroxide (Ca (OH) ₂ ) to form dense CSH hydrates. It is effective to secure the visibility of color concrete by reducing the whitening phenomenon by dissolution of calcium hydroxide and alkali component.

In addition, the pozzolanic material is composed of amorphous silica or silicate minerals, and is constrained by chemical reaction with alkali ions in cement or alkali ions penetrating from the outside, thereby reducing the amount of free alkali ions in concrete. the movement and penetration of the alkali ion is more difficult alkali-aggregate reaction and suppress the increase of the water tightness has a chloride ion (Cl ^-) is effective for preventing the deterioration of the concrete to hydrate and also acts effectively in reducing the rate of diffusion.

However, when the content of the pozzolanic material is high, the amount of Ca (OH) ₂ required for the reaction is insufficient, so that the hydration of the pozzolanic material is not sufficiently performed, thereby reducing the strength and durability of the concrete pavement. In addition, the condensation time of concrete increases more than twice as much as that of general concrete, which increases the time required for joint cutting after laying concrete, and the construction period increases due to the increase in the age of curing management, and it is difficult to proceed smoothly. There is a problem.

In addition, when the amount of bleeding of concrete is high in the color concrete pavement, the soluble substance in cement rises with the bleeding water and precipitates on the surface, or the surface of the concrete with the low specific gravity gypsum, fine aggregate and cement fine powder and pigment together with the bleeding water As it rises, whitening or staining occurs. In this case, the use of pozzolanic material reduces the amount of bleeding and is effective in suppressing discoloration of the concrete surface.

Therefore, the addition amount of the pozzolanic material should be determined in consideration of this point, and it is appropriate to make the range of 1 to 25% by weight, which is excellent in long-term strength expression and durability, but does not increase the setting time during the production of color cement.

The color cement composition for bus lanes of the present invention can be prepared by uniformly mixing the materials composed of the above-described composition ratio, and preferably can be prepared by putting in a high-efficiency powder mixer and stirring.

Color concrete pavement not only emphasizes the strength, durability, but also the aesthetics and visibility of concrete, so it is important to disperse the pigment homogeneously in concrete. The concrete pavement is manufactured in a concrete mixer with a low slump of less than 5 cm and then transported to the site by a dump truck and constructed on slip foam fabers. In this process, color concrete may be manufactured by directly adding the pigment to the concrete mixer.However, unlike general concrete, the road paving concrete has low fluidity, so when the pigment is directly injected into the concrete mixer, the color may not be sufficient due to insufficient dispersion and homogeneity of the particles. There is a disadvantage that it is not homogeneous and the amount of pigment used is increased.

Pigment is the most expensive material used in the production of color cement as the amount of use increases the manufacturing cost of the cement has a problem of low economic efficiency. Therefore, in order to increase the homogeneity and brightness of the concrete color, it is important to secure the homogeneity in manufacturing cement. In addition, even when the materials are simply mixed, the homogeneity of the whole material is not sufficiently secured, and there is a fear of variation of the concrete properties. Therefore, the present invention solves this problem by mixing the binder in advance with a high efficiency powder mixer.

In the case of preparing the binder of the composition ratio by mixing in advance with a high-efficiency powder mixer, the pigment and cement materials are evenly dispersed to improve the visibility and color homogeneity of the color concrete packaging, and the amount of the pigment required to obtain the desired chromaticity is reduced, and the cement particles Hydration is homogeneous and smooth, which is advantageous for strength expression and durability of concrete.

By mixing as described above, it was possible to produce color cement of uniform chromaticity.

Hereinafter, an embodiment of the present invention is shown below, but the scope of the present invention is not limited to this embodiment.

<Calcium hydroxide quantification experiment example>

Figure 1 and Table 3 is a comparison between the ordinary portland cement and crude steel portland cement prescribed in KS L5201, blast furnace slag cement substituted 40% by weight blast furnace slag powder to ordinary portland cement, the ordinary color cement of the present invention 57% by weight of cement, 57% by weight of blast furnace slag powder, 8% by weight of fly ash, and anhydrous gypsum (3% by weight, 5% by weight) as an additive. 37% by weight of blast furnace slag powder and 8% by weight of fly ash were used as cement to replace anhydrous gypsum (3% by weight, 5% by weight) as an additive and prepared by mixing 5% by weight of iron oxide pigment in each cement. It is the result of quantitative analysis of Ca (OH) ₂ production through thermal analysis of a hardened cement paste by TG-DSC.

The components of each material used in this example are shown in Table 1 and Table 2.

[Table 1] Chemical Compositions of Cement and Admixtures

[Table 2] Chemical Compositions of Iron Oxide Pigments

In the graph of FIG. 1, the decomposition temperature of calcium hydroxide is 420 ° C. to 500 ° C., and the amount of calcium hydroxide (Ca (OH) ₂ ) produced in slag cement is reduced, compared to ordinary portland cement and crude portland cement. When slag powder and fly ash were added, calcium hydroxide (Ca (OH) ₂ ) production was greatly reduced, and when calcium hydroxide (3% by weight) was added, calcium hydride (Ca (OH) ₂ ) production was further reduced. You can see that. That is, the cement of the present invention has the effect of reducing the amount of calcium hydroxide (Ca (OH) ₂ ) in the hydrate, increasing the amount of dense CSH hydrate produced to reduce discoloration of color concrete due to whitening phenomenon. In addition, the dense hydrate is produced to increase the strength, water tightness, chemical resistance and durability of the concrete.

[Table 3] Calcium hydroxide quantification results by thermal analysis

<Example of XRD Analysis According to Hydration Age>

FIG. 2 shows no addition of 3% by weight, 6% by weight, 9% by weight of anhydrous gypsum to a combination of 57% by weight of ordinary Portland cement, 27% by weight of blast furnace slag, 8% by weight of fly ash, and 5% by weight of inorganic iron oxide pigment. The XRD peak changes of each mineral according to the hydration age of one sample. In each graph, 1D (red) is 1 day old, 3D (green) is 3 day old, and 7D (sky blue) is the peak at 7 day old age. Indicates. In the absence of anhydrous gypsum, there is no peak of anhydrous gypsum, and in the case of 3 wt% added samples, the peak of anhydrous gypsum is large at 1 day of age, but it is greatly reduced after 3 days, and the peak in 6 wt% added samples is large until 3 days After 7 days it decreased significantly. However, the peak of anhydrous gypsum in the 9 wt% added sample also shows a large peak of anhydrous gypsum even during 7 days of age, and it can be seen that anhydrous gypsum remains large even after the strength is sufficiently developed. The gypsum remaining without consumption reacts with C ₃ A, C ₄ AF and monosulfate to form an expandable ethrinzide hydrate, causing damage to the structure. It is suitable.

<Example of Evaluation of Chloride Ion Penetration Resistance of Concrete>

Table 4 shows the common Portland cement alone (Comparative Example 1, no pigment), ordinary Portland cement + pigment 5% by weight (Comparative Example 2), crude steel Portland cement + pigment 5% by weight and blast furnace slag cement + pigment 5% by weight ( In Comparative Example 3) as a comparative example, 57% by weight of ordinary portland cement of the present invention, 27% by weight of blast furnace slag powder, 8% by weight of fly ash, 3% by weight of anhydrous gypsum, and 5% by weight of iron oxide pigment were used. Example 1 concrete of Table 5 using crude steel cement of 57% by weight of crude steel portland cement, 27% by weight of blast furnace slag powder, 8% by weight of fly ash, 3% by weight of anhydrous gypsum, and 5% by weight of iron oxide pigment. The specimens that were cured in water for 28 days after the specimens were prepared by blending were evaluated for the chloride ion penetration resistance of concrete by ASTM C1202 (Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chlorideions Penetration) test. .

[Table 4] Chlorine Ion Penetration Resistance

[Table 5] Concrete Mixing Conditions

In the ASTM C 1202 test method, a concrete test specimen was mounted at the center of a diffusion cell, 0.3M NaOH solution was added to the anode, 3% NaCl solution was applied to the cathode, and 60V DC voltage was applied to both ends of the cell for 6 hours. It is a method to qualitatively evaluate the penetration resistance of chloride ions from the total pass charge by measuring the amount of current flowing through the test body.

According to the test results, when 5 wt% of iron oxide pigment was added to the ordinary portland cement, the total passage charge increased compared to the non-addition, and the water-tightness decreased. Therefore, the crude steel portland cement exhibited better water-tightness than the ordinary portland cement. I got it. The slag cement has a lower total charge amount than the ordinary portland cement, and the watertightness is increased, and the general and crude color cement of the present invention has a very low total pass charge value of 1000 Coulombs or less, which is very excellent in watertightness.

Example of measuring compressive strength and flexural strength

The following Table 6. shows ordinary portland cement alone (Comparative Example 1, no pigment), crude steel portland cement (Comparative Example 2, no pigment), 5% by weight, 5% by weight and 7% by weight of ordinary Portland cement (Comparative Example 3) 5), blast furnace slag cement + pigment 5% by weight (Comparative Example 6) and crude steel portland cement + pigment 5% by weight (Comparative Example 6), the ordinary portland cement 57% by weight of the present invention, blast furnace slag powder 27% by weight, 8% by weight of fly ash, 3% by weight of anhydrous gypsum and 5% by weight of each pigment were added to ordinary color cement in the compositions of Examples 1 to 4 and Examples 1 to 4, respectively. The result of testing the compressive strength and the bending strength of mortar by the specification of JIS A 5308 by using what was replaced by Examples 5-8. In Table 6. As pigments, iron oxide (Fe2O3) was red, yellow iron oxide (FeOOH) was yellow, chromium green, blue blue, and black carbon black (C) were used as pigments.

According to the test results, when 3% by weight, 5% by weight and 7% by weight of pigments are substituted in ordinary Portland cement, the compressive strength of cement tends to decrease with increasing amount of substitution. However, the important flexural strength tends to increase in road paving concrete, with the maximum value at 5% by weight. Therefore, the addition amount of the general iron oxide pigment is about 10% by weight or less, but considering the experimental results, economics and the visibility of the concrete, it is preferable that the appropriate addition amount of the iron oxide pigment is preferably 3 to 7% by weight in the present invention. In Example 4 in which the pigment was added to the slag cement, the initial strength was lowered but the long-term strength was increased compared to Example 2 in which the same amount of the pigment was added to the ordinary portland cement. Expression was shown.

[Table 6] Mortar strength test results according to JIS A 5308

The ordinary color cement and the crude color cement of the present invention have a lower three-day strength than the ordinary portland cement and the crude steel portland cement without the pigment, but have excellent compressive strength and flexural strength for 28 days. In addition, the strength of 3 days was lower than that of cement added with other pigments, but the strength of 7 days and 28 days was excellent.

<Alkali-aggregate reaction evaluation example>

The following Table 7 shows ASTM C 126 Potential Alkali Reactivity of Aggregates (Mortar-), with the ordinary portland cement as Comparative Example 1 and the crude steel portland cement as Comparative Example 2, the ordinary color cement as Example 1 and the crude steel cement as Example 2. It is the result of evaluating alkali-aggregate reaction by Bar Method), and the aggregate used here was a reactive aggregate produced in Korea.

TABLE 7 Alkali-aggregate reaction test (ASTM C 1260 mortar rod method)

This method evaluates whether aggregate aggregates cause alkali-aggregate reactions due to alkali in the cement and alkali that penetrates from the outside, and this is a method of evaluating the possibility of cracking and breakage due to expansion. A specimen of 25.4 mm x 254 mm was produced and cured in 80 ° C sodium hydroxide solution (NaOH) to evaluate the expansion rate. Alkali-aggregate reactions are influenced not only by the characteristics of the aggregate, but also by the alkali content in the cement and by the immobilization of the alkali component by the cement, the diffusion resistance to alkali ions of the hydrate, and the test results determine that the expansion ratio is 0.10% or less.

In Comparative Example 1 and Comparative Example 2, the expansion rate is about 0.20%, but Example 1 (usually color cement) and Example 2 (bare steel color cement) of the present invention have an expansion ratio of 0.7% or less even when using a reactive aggregate. It was possible to suppress the alkali-aggregate reaction. Recently, road breakage due to alkali-aggregate reaction has been observed in some sections of concrete roads in Korea, and the cement of the present invention inhibits alkali-aggregate reaction by alkali ions penetrated by spraying alkali ions and snow plows in cement and cracks. And to reduce the breakage can improve the life of the concrete pavement.

<Example of Evaluation of Concrete Surface Wear Resistance>

Next, FIG. 3 shows ASTM C 779: Standard Test Method for Abrasion Resistance of ordinary portland cement as Comparative Example 1 and crude steel portland cement as Comparative Example 2, and ordinary color cement as Example 1 and crude steel cement as Example 2. It is the result of evaluating the surface abrasion resistance of concrete by Horizontal Concrete Surfacesd.

If the surface wear is severe in the color concrete pavement, the aggregate is exposed and the visibility is reduced, and the slip resistance is reduced, increasing the risk of an accident. Example 1 ordinary color cement and Example 2 crude steel cement of the present invention have a greater surface wear resistance than Comparative Example 1 ordinary portland cement and Comparative Example 2 crude steel portland cement, and therefore, retaining performance of visibility and slip resistance of color concrete It can be said to be good cement.

<Example of Evaluation of Insulation Temperature Rise Characteristics>

Next, FIG. 4 compares the heat insulation temperature rise characteristics of concrete using Portland cement as Comparative Example 1 and slag cement as Comparative Example 2 and ordinary color cement as Example 1. FIG.

Cement reacts with water to generate heat of hydration in the process of condensation and hardening, and the temperature rises rapidly due to hydration heat in concrete pavement, and as the temperature increase increases, the temperature difference between the surface and the inside increases, which may cause cracking. Since the ordinary color cement of the present invention has less hydration calorific value than ordinary portland cement and slag cement as shown in Fig. 4, there is little concern about the occurrence of cracks due to hydration heat due to the low rate of temperature rise and the maximum temperature. Packing is possible.

<Example of evaluation of dry shrinkage characteristics>

Next, FIG. 5 compares the dry shrinkage characteristics of concrete using the ordinary portland cement as Comparative Example 1 and the slag cement as Comparative Example 2, and the ordinary color cement as Example 1. FIG.

Concrete shrinks due to evaporation of moisture during the hardening process. In concrete pavement, when hardening starts after pouring, it cuts to a certain depth and interval to induce a constant crack (joint) to prevent breakage and cracking of the concrete. However, if the dry shrinkage of the concrete is large, cracks also occur at parts other than the joints, which causes premature failure of the concrete pavement and degradation of durability.

As shown in Figure 5, the color cement of the present invention has less dry shrinkage than ordinary portland cement and slag cement. Therefore, it is possible to reduce the occurrence of cracks in concrete pavement, concrete pavement with excellent durability.

1 is a graph showing the results of the quantitative analysis of Ca (OH) _{2 in the} cement paste cured product of Examples and Comparative Examples of the present invention through TG-DSC thermal analysis.

2 is a view showing the XRD peak change of each mineral according to the hydration age of the other samples in the content (additive-free, 3% by weight, 6% by weight, 9% by weight) of anhydrous gypsum.

3 is a result of evaluating the wear resistance of the concrete surface of the Examples and Comparative Examples of the present invention.

4 is a view comparing the concrete insulation temperature rise characteristics of the examples and comparative examples of the present invention.

5 is a view comparing the concrete dry shrinkage characteristics of the examples and comparative examples of the present invention.

Claims (2)

In the color cement composition for the production of driveway concrete concrete, 30 to 80% by weight of Portland cement, 5 to 60% by weight of blast furnace slag, 1 to 25% by weight of fly ash or silica fume, 1 to 7% by weight of type II anhydrous gypsum and 2 to 10% by weight of inorganic pigment A color cement composition for driveway, characterized in that. The method of claim 1, wherein the inorganic pigment is iron oxide (Fe ₂ O ₃ ), lead chromate (PbCrO ₄ ), lead molybdate (PbMoO ₄ ), cadmium red (Cd (S _x Se _1-x )), lead tetraoxide (Pb) ₃ O ₄ ), yellow iron oxide (FeOOH), lead chromate (PbCrO ₄ ), chrome green, ultramarine blue (Na _8-10 Al ₆ Si ₆ O ₂₄ S _2-4 ), blue (Fe ₇ (CN) ₁₈ (H ₂₎ O) _x , X = 14 to 16), black iron oxide (Fe ₂ O ₃ ), carbon black (C) and titanium dioxide (TiO ₂ ) for at least one material selected from the group consisting of Color cement composition.

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