KR101913645B1 - Manufacturing method of mixture of early strength for cement concrete - Google Patents

Abstract

The present invention relates to a manufacturing method of an early strength mixture for cement concrete and comprises a calcium compound, a silicide compound, a hydroxide such as alkali metal, a dispersant, and water. According to the present invention, the early strength mixture for cement concrete is able to highly reveal early strength of concrete despite reducing a content of cement and is superior in convenience of use and safety of long-term storage since the early strength mixture for cement concrete is manufactured as one component.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for producing a crude steel mixture for cement concrete,

The present invention relates to a method for manufacturing a crude steel mixture for cement concrete, and more particularly, to a method for manufacturing a crude steel mixture for a cement concrete which can improve the production process of a crude steel mixture and exhibit a higher initial strength and storage stability than a conventional cement concrete mixture ≪ / RTI >

It is required to use cheap industrial byproducts such as fly ash and blast furnace slag which can reduce the proportion of cement when replacing cement concrete. The amount of such industrial byproducts is increasing year by year and is more than 20 million tons per year, which is desirable as a substitute for cement. However, when the industrial byproducts are applied, the early strength of the concrete is decreased, and therefore, there is an increasing need for a crude steel additive that can solve this problem.

In addition, when concrete is laid in the winter season, the strength of the concrete is significantly delayed and the construction period is lengthened. In order to solve this problem, heat is applied around the poured concrete to shorten the duration of the strength. However, since these points lead to an increase in construction cost, shortening of the time period of the strength of the concrete is a major problem.

In addition, the early strength of concrete is an important part of precast concrete, which is produced by pouring concrete into a mold. Especially in precast, steam curing using steam quickly develops the strength of concrete, which consumes a large amount of energy. Precreation is one of important parts of the molding frame used to produce molded concrete of a certain shape. Therefore, the early strength development of concrete is an important factor to use less energy and increase the turnability of the mold.

Conventionally, various materials have been applied to increase the early strength of cement concrete. However, it is troublesome to use the materials when they are mixed with the materials necessary for manufacturing cement concrete. In addition, such materials may cause problems such as precipitation and reaction during simple mixing.

Korean Patent No. 120942 discloses a method of adjusting the strength by adjusting the strength of the concrete to be increased by increasing the amount of cement and the amount of additional aggregate. .

Korean Patent Registration No. 1396859 discloses a method of increasing the strength by adding a liquid roughing agent and a powder hardening agent in concrete production. However, this has the problem that the respective coercive agents must be managed and used, and the mixing ratio must be considered.

Therefore, there is a great demand in the industry for a crude steel mixture for cement concrete which is simple and economical and excellent in early strength and storage stability.

Korea Patent No. 120942 Korean Patent Publication No. 1396859

It is an object of the present invention to provide a method for producing a crude steel mixture for a one-pack type cement concrete having excellent early strength, versatility, convenience, storage stability and economical efficiency.

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In order to achieve the above object, the present invention provides a crude steel mixture for cement concrete,

100 parts by weight of a calcium compound selected from calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof,

1 to 100 parts by weight, preferably 5 to 85 parts by weight, of a silicon compound selected from silicon dioxide, silica fume, sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash, bottom ash, More preferably 10 to 70 parts by weight,

1 to 100 parts by weight, preferably 5 to 10 parts by weight of an alkali metal or an alkaline earth metal selected from the group consisting of nitrates, formates, nitrates, nitrates, sulfates, thiosulfates, carbonates, To 85 parts by weight, more preferably from 10 to 70 parts by weight,

1 to 80 parts by weight, preferably 3 to 70 parts by weight, more preferably 5 to 60 parts by weight, of a dispersant and

45 to 400 parts by weight, preferably 80 to 380 parts by weight, and more preferably 110 to 330 parts by weight of water,

Preferably 0.1 to 10 parts by weight, more preferably 1 to 10 parts by weight, and even more preferably 3 to 8 parts by weight per 100 parts by weight of the cement of the cement concrete, Is given.

Further, the crude steel mixture for cement concrete of the present invention contains, per 100 parts by weight of the calcium compound,

0.01 to 15 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.01 to 5 parts by weight of cement may be further included.

The solid content of the crude steel mixture for cement concrete may be 10 to 70% by weight, preferably 15 to 65% by weight, and more preferably 20 to 60% by weight.

Further, the crude steel mixture for cement concrete contains, per 100 parts by weight of the calcium compound,

0.001 to 5 parts by weight, preferably 0.1 to 5 parts by weight, of the antifoaming agent.

Further, the crude steel mixture for cement concrete contains, per 100 parts by weight of the calcium compound,

0.001 to 5 parts by weight, preferably 0.1 to 1 part by weight, of a thickening agent.

The viscosity of the crude steel mixture for cement concrete may be 10 to 1000 cPs.

The annual viscosity change of the crude steel mixture for cement concrete may be 0 to 1000 cPs.

The pH of the crude steel mixture for cement concrete may be 9 to 14.

Meanwhile, the method for producing a crude steel mixture for cement concrete according to the present invention comprises

(A) 100 parts by weight of a calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof,

30 to 120 parts by weight, preferably 40 to 100 parts by weight of water are mixed to prepare an aqueous solution of a calcium compound;

(B) per 100 parts by weight of the calcium compound,

1 to 100 parts by weight, preferably 5 to 85 parts by weight, of a silicon compound selected from silicon dioxide, silica fume, sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash, bottom ash, More preferably 10 to 70 parts by weight,

1 to 100 parts by weight, preferably 5 to 10 parts by weight of an alkali metal or an alkaline earth metal selected from the group consisting of nitrates, formates, nitrates, nitrates, sulfates, thiosulfates, carbonates, To 85 parts by weight, more preferably from 10 to 70 parts by weight,

Mixing 10 to 240 parts by weight, preferably 60 to 200 parts by weight of water to prepare a silicon compound and an aqueous solution of an alkali metal or alkaline earth metal compound;

(C) per 100 parts by weight of the calcium compound,

1 to 80 parts by weight, preferably 3 to 70 parts by weight, more preferably 5 to 60 parts by weight, of a dispersant and

Mixing 5 to 40 parts by weight, and preferably 10 to 30 parts by weight of water to prepare an aqueous solution of a dispersant; And

(D) adding an aqueous solution of the calcium compound, a silicon compound and an aqueous solution of an alkali metal or alkaline earth metal compound to the aqueous solution of the dispersant.

The method for producing a crude steel mixture for cement concrete according to the present invention comprises

The step (D) may be carried out in a reactor equipped with an anchor stirrer and a dissolver stirrer.

The reaction tank may have 2 to 6, preferably 2 to 4, more preferably 2 to 3 dissolver type stirrers.

The dissolver-type agitator may be superior to the flow in which the rotation about the rotation axis is parallel to the rotation axis.

In the method for producing a crude steel mixture for cement concrete according to the present invention, in step (D), an aqueous solution of a calcium compound, a silicon compound, and an aqueous solution of an alkali metal or an alkaline earth metal compound may be dropped onto the impeller of the dissolver type stirrer.

In the method for producing a crude steel mixture for cement concrete according to the present invention, the calcium compound aqueous solution, the silicon compound, and the alkali metal or alkaline earth metal compound aqueous solution may be added dropwise in the step (D).

In the step (D), the calcium compound aqueous solution may be added dropwise for 0.5 to 10 hours, preferably 1 to 6 hours.

In the step (D), the silicon compound and the aqueous solution of the alkali metal or alkaline earth metal compound are added dropwise for 0.5 to 10 hours, preferably 1 to 8 hours.

Also, in the step (D), the reaction tank may be maintained at 5 to 95 ° C, preferably 10 to 60 ° C.

The method for producing a crude steel mixture for cement concrete according to the present invention comprises

After step (D) above,

The crude steel mixture for cement concrete is calcined at a temperature of 5 to 95 캜, preferably 7 to 80 캜, more preferably 10 to 60 캜 for 0.5 to 24 hours, preferably 0.5 to 18 hours, more preferably 0.5 to 12 hours For the first time.

The method for producing a crude steel mixture for cement concrete according to the present invention comprises

After step (D) above,

And a dispersion treatment step of passing the crude steel mixture for cement concrete through a bead mill.

The bead average particle diameter of the bead mill may be 0.1 to 1 mm, preferably 0.3 to 0.8 mm.

The beads of the bead mill may be selected from the group consisting of ceramics such as zirconia and alumina, glass, aluminum alloys, and mixtures thereof.

The method for producing a crude steel mixture for cement concrete according to the present invention comprises

After step (D) above,

And filtering the crude steel mixture for cement concrete.

The average pore size of the filtration membrane in the filtration may be 0.1 to 10 mu m, preferably 0.5 to 5 mu m.

The solid content of the crude steel mixture for cement concrete may be 10 to 70% by weight, preferably 15 to 65% by weight, and more preferably 20 to 60% by weight.

In addition, the method for producing a crude steel mixture for cement concrete is characterized in that, per 100 parts by weight of the calcium compound,

0.001 to 5 parts by weight, preferably 0.1 to 5 parts by weight, of the antifoaming agent.

In addition, the method for producing a crude steel mixture for cement concrete is characterized in that, per 100 parts by weight of the calcium compound,

0.001 to 5 parts by weight, preferably 0.1 to 1 part by weight, of a thickening agent.

In the preparation of the crude steel mixture for cement concrete, the stirring may be carried out in the mixing index range of 0.5 to 6, preferably 0.7 to 4.5, more preferably 1 to 3. [

On the other hand, the crude steel mixture for cement concrete of the present invention is characterized by being produced by the above-mentioned method.

When the cementitious concrete mixture for cement concrete according to the present invention is applied to cement concrete, the early strength is increased even at a low cement content, so that it can be expected to shorten construction time, cost, and energy saving. This early strength development leads not only to the use of conventional concrete but also to the steam pre-casting pre-casting sector, resulting in a reduction in steam consumption, which is remarkable for the inventive crude steel mixture. Compared to the prior art in which various materials have to be mixed at a predetermined ratio for expressing early strength, the present invention is a one-pack type, so that the convenience of the user is maximized and the precipitation of the product , Degradation of performance and the like can be solved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a manufacturing process of a crude steel mixture for cement concrete according to the present invention. FIG.
2 is a schematic view showing a cross section of a reaction tank used for producing a crude steel mixture for cement concrete according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail.

Prior to this description, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings, and the contents described in this specification do not necessarily represent the technical ideas of the present invention, It should be understood that there may be many variations that can be substituted for these. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In this specification, the Mixing Index is defined as follows:

Mixed Index

= (Anchor stirrer uniformity [kW] * Anchor stirrer rotation speed [rpm]) ^ 1/3

  * (Diameter of anchor stirrer / reactor diameter).

The crude steel mixture for cement concrete according to the preferred embodiment of the present invention may contain calcium compounds selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof, silicon dioxide, silica fume, sodium silicate A nitrate, a nitrite, a sulfate, a thiosulfate, a carbonate, a nitrate, a nitrate, or a salt of an alkali metal or an alkaline earth metal selected from the group consisting of sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash, An alkali metal or alkaline earth metal compound selected from the group consisting of chlorides, halides and mixtures thereof, a dispersant, and water.

Wherein the crude steel mixture for cement concrete contains 100 parts by weight of a calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof, 1 to 100 parts by weight, preferably 5 to 85 parts by weight, more preferably 10 to 30 parts by weight, of a silicon compound selected from the group consisting of sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash, bottom ash, An alkali metal or an alkaline earth metal compound selected from the group consisting of a nitrate, a nitrate, a nitrate, a sulfate, a thiosulfate, a carbonate, a chloride, a halide and a mixture thereof of an alkali metal or an alkaline earth metal; 100 parts by weight, preferably 5 to 85 parts by weight, more preferably 10 to 70 parts by weight Lt; / RTI > And the dispersion contains 1 to 80 parts by weight, preferably 3 to 70 parts by weight, more preferably 5 to 60 parts by weight of the dispersant, the water is 45 to 400 parts by weight, preferably 80 to 380 parts by weight, Lt; RTI ID = 0.0 > 110 < / RTI > The crude steel mixture for cement concrete according to the present invention is used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 1 to 10 parts by weight, more preferably 3 to 8 parts by weight, By weight, to give the cement concrete a toughness.

The calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof activates the base during the condensation and curing of the cement to promote the formation of calcium silicate hydrate. In the above group, calcium oxide absorbs water and carbon dioxide and is decomposed into calcium hydroxide and calcium carbonate.

In order to accelerate the formation of calcium silicate hydrate by activating the base during the curing and curing process of the cement concrete, the crude steel mixture for cement concrete according to the present invention may contain silicon dioxide, silica fume, sodium silicate, potassium silicate 1 to 100 parts by weight, preferably 5 to 85 parts by weight, more preferably 10 to 70 parts by weight, of a silicon compound selected from the group consisting of water glass, aluminum silicate, calcium silicate, fly ash, bottom ash and mixtures thereof . When the content of the silicon compound is within the above range, the reaction rate of concrete can be suitably maintained, and desired early strength can be obtained.

Further, the crude steel mixture for cement concrete according to the present invention may contain, per 100 parts by weight of the calcium compound, an alkali metal or alkaline earth metal nitrate, nitrate, nitrite, sulfate, thiosulfate, carbonate, chloride, halide and mixtures thereof 1 to 100 parts by weight, preferably 5 to 85 parts by weight, more preferably 10 to 70 parts by weight, of the alkali metal or alkaline earth metal compound selected from the group When the content of the alkali metal or alkaline earth metal compound is within the above range, a proper hydration reaction rate can be ensured and desired early strength can be obtained.

The alkali metal or alkaline earth metal compound weakens the coating around the calcium silicate hydrate and accelerates its crystal growth so that condensation and curing of the cement can proceed easily. These compounds are activated by the above-mentioned calcium compounds to participate in the reaction. Examples of such alkali metal or alkaline earth metal compounds include sodium acetate, calcium acetate, potassium acetate, acetate, calcium formate, and formate salts as organic components. Examples of the inorganic components include calcium nitrate, calcium nitrite, calcium chloride, calcium bromide, calcium iodide, Soluble calcium salts, iron chloride, magnesium chloride, sodium chloride, sulphates, potassium hydroxide, carbonates, thiosulphates, calcium aluminate silicates and the like.

The dispersant inhibits intergranular aggregation such as a calcium compound, a silicon compound, an alkali metal or an alkaline earth metal compound constituting the crude steel mixture of the present invention, and allows the particles to be separated from each other by electrostatic or physical repulsive force. Through this, uniform strength is exhibited in the entire area of cement concrete, and sufficient workability can be ensured while reducing the amount of water to be blended. The content of such a dispersant may be 1 to 80 parts by weight, preferably 3 to 70 parts by weight, more preferably 5 to 60 parts by weight per 100 parts by weight of the calcium compound. If the content of the dispersing agent is less than 1 part by weight, the viscosity of the crude steel mixture becomes excessively high, making it difficult to manufacture and use. On the other hand, if the content exceeds 80 parts by weight, not only the economical efficiency is lowered but also phase separation may occur between the components of the crude steel mixture. In addition, in order to solve this problem, the defoaming agent may be used in an undesirable manner. In addition, a large amount of the dispersing agent may cause deterioration of the early strength of the concrete.

The water content may be 45 to 400 parts by weight, preferably 80 to 380 parts by weight, more preferably 110 to 330 parts by weight per 100 parts by weight of the calcium compound. If the content of water is less than 45 parts by weight, the viscosity of the crude steel mixture becomes excessively high, making it difficult to manufacture and use. Conversely, if the water content exceeds 400 parts by weight, the cost of the logistics will increase, and phase separation may occur among the components of the crude steel mixture.

Further, the crude steel mixture for cement concrete of the present invention may contain 0.01 to 15 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.01 to 10 parts by weight of cement per 100 parts by weight of the calcium compound, To 5 parts by weight. When the content of the cement is within the above range, it is possible to express the steel-making performance more quickly as described above.

The solid content of the crude steel mixture for cement concrete may be 10 to 70% by weight, preferably 15 to 65% by weight, more preferably 20 to 60% by weight. When the solid content is within the above range, it is possible to lower the cost of logistics while exhibiting desired performance of the steel making.

Further, the crude steel mixture for cement concrete of the present invention may further contain 0.001 to 5 parts by weight, preferably 0.1 to 5 parts by weight, of a defoaming agent per 100 parts by weight of the calcium compound. When the content of the antifoaming agent is within the above range, it is possible to suppress the strength reduction due to the bubbles in the cement concrete while considering the economical efficiency.

The antifoaming agent is used to remove air bubbles generated when components constituting the crude steel mixture for cement concrete of the present invention are mixed. When bubbles are generated in the crude steel mixture for cement concrete, the strength of the concrete may be reduced.

The crude steel mixture for cement concrete may further contain 0.001 to 5 parts by weight, preferably 0.01 to 1 part by weight, of a thickener per 100 parts by weight of the calcium compound. When the content of the thickener is within the above range, it is possible to ensure a suitable viscosity which allows smooth work while suppressing the phase separation of the constituent components.

Also, the viscosity of the crude steel mixture for cement concrete may be 10 to 1000 cPs. When the viscosity is within the above range, it is possible to smoothly perform work while suppressing the phase separation of the constituent components, thereby ensuring an appropriate level of workability.

Also, the annual viscosity change of the crude steel mixture for cement concrete may be 0 to 1000 cPs. When the annual viscosity change amount is 1000 cPs or less, an appropriate range of merchantability can be secured.

Also, the pH of the crude steel mixture for cement concrete may be 9 to 14. When the pH is within the above range, a hydration reaction at a high rate can be expressed, which is preferable.

The process for producing a crude steel mixture for cement concrete according to the present invention will be described in more detail as follows.

(1) Reactor plants for the preparation of crude steel mixtures

The reaction vessel used for preparing the crude steel mixture for cement concrete according to the present invention is equipped with an anchor type stirrer and a dissolver type stirrer, and a dropping line is provided so that each aqueous solution can be dropped into the impeller on the impeller of the dissolver type stirrer. Although the dropwise addition of the aqueous solution may be carried out in the liquid level, it is more preferable that the dropwise addition is carried out in the liquid in terms of storage stability.

The dissolver type stirrer shown in Fig. 3 is superior to the flow in which the rotation about the rotation axis is parallel to the rotation axis, like the anchor type stirrer. This is distinguished from a propeller-type axial flow impeller or a turbine-type impeller, and the crude mixture produced in an environment in which rotational flow dominates exhibits better storage stability.

The reaction tank may have 2 to 6, preferably 2 to 4, more preferably 2 to 3 dissolver type stirrers. When two or more dissolver type stirrers are provided, the storage stability is improved Respectively. Furthermore, it is preferable that the drop line is formed on the impeller of each of the dissolver type stirrers, and a plurality of drop lines are formed in the reaction tank. It is preferable that the anchor type stirrer is stirred at 10 to 1000 rpm, and the dissolver type stirrer is stirred at 500 to 3000 rpm, but the present invention is not limited thereto.

(2) Preparation of calcium compound aqueous solution

100 parts by weight of a calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof and 30 to 120 parts by weight, preferably 40 to 100 parts by weight, To prepare an aqueous solution of the compound.

(3) Preparation of aqueous solutions of silicon compounds and alkali metal or alkaline earth metal compounds

1 to 100 parts by weight of a silicon compound selected from the group consisting of silicon dioxide, silica fume, sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash and bottom ash and mixtures thereof per 100 parts by weight of the calcium compound 5 to 85 parts by weight, more preferably 10 to 70 parts by weight, of an alkali metal or alkaline earth metal, such as a nitrate, a nitrate, a nitrate, a sulfate, a thiosulfate, a carbonate, a chloride, a halide and mixtures thereof 1 to 100 parts by weight, preferably 5 to 85 parts by weight, more preferably 10 to 70 parts by weight, and 10 to 240 parts by weight, preferably 60 to 200 parts by weight of an alkali metal or alkaline earth metal compound selected from To prepare a silicon compound and an aqueous solution of an alkali metal or alkaline earth metal compound.

(4) Preparation of aqueous dispersion of dispersant

Preferably 1 to 80 parts by weight, preferably 3 to 70 parts by weight, more preferably 5 to 60 parts by weight, and 5 to 40 parts by weight, preferably 10 to 30 parts by weight, of the dispersing agent per 100 parts by weight of the calcium compound To prepare an aqueous solution of the dispersant.

(5) Preparation of crude steel mixture

A crude steel mixture for cement concrete according to the present invention is prepared by mixing the aqueous solution of calcium compound, the silicon compound, and the aqueous solution of the alkali metal or alkaline earth metal compound and the aqueous solution of the dispersant. Preferably, the mixing is performed by first adding an aqueous solution of the dispersant in the reaction tank and adding an aqueous solution of a calcium compound, a silicon compound, and an aqueous solution of an alkali metal or an alkaline earth metal compound.

Particularly, the dropwise addition of the aqueous calcium compound solution or the like is preferably added dropwise to the impeller of the dissolver-type stirrer in the reaction tank, and stirring is more preferable because the storage stability can be improved. The anchor stirrer is also agitated at the same time. The dropping time is in the range of 0.5 to 10 hours, preferably 1 to 8 hours for the calcium compound aqueous solution, 0.5 to 10 hours, preferably 1 to 6 hours for the silicon compound, and for the aqueous solution of the alkali metal or alkaline earth metal compound, It is preferable that the loading of the two aqueous solutions start at the same time. During the dropwise addition, the temperature in the reaction tank is maintained at 5 to 95 캜, preferably 10 to 60 캜.

After completion of the addition, the crude steel mixture for cement concrete is allowed to stand at a temperature of 5 to 95 캜, preferably 7 to 80 캜, more preferably 10 to 60 캜 for 0.5 to 24 hours, preferably 0.5 to 18 hours, Lt; / RTI > for 0.5 to 12 hours. When the holding temperature and the holding time are within the above range, vaporization of water can be prevented and the reaction can be sufficiently advanced while maintaining economical efficiency, thereby ensuring the performance and stability of the instant invention crude steel mixture.

0.01 to 15 parts by weight, preferably 0.01 to 10 parts by weight, more preferably 0.01 to 5 parts by weight of cement, 0.001 to 5 parts by weight of defoamer per 100 parts by weight of the calcium compound as described above, 0.1 to 5 parts by weight, preferably 0.001 to 5 parts by weight, and preferably 0.1 to 1 part by weight, of a thickener.

(6) Dispersing treatment process

And a dispersion treatment step of passing the crude steel mixture for cement concrete through a bead mill. The average particle diameter of the beads may be 0.1 to 1 mm, preferably 0.3 to 0.8 mm. If the average particle diameter is less than the above range, the average particle diameter of the beads is too small to cause the beads to escape from the bead mill, The bead diameter is too small to be dispersed more than the crude mixture to be mixed. On the contrary, if the ratio exceeds the above range, the particle size of the bead becomes too large as compared with the crude mixture, and the dispersion efficiency is lowered. The beads may be selected from the group consisting of ceramics such as zirconia or alumina, glass, aluminum alloys, and mixtures thereof. Through the dispersion treatment by the bead mill, the storage stability of the crude steel mixture for cement concrete according to the present invention is enhanced, and further, the compressive strength of the cement mortar and cement concrete containing the same is increased.

(7) Filter treatment process

The method for producing a crude steel mixture for cement concrete according to the present invention may further comprise filtering the crude steel mixture for cement concrete. The average pore size of the filtration membrane in the filtration may be 0.1 to 10 mu m, preferably 0.5 to 5 mu m. If the average pore size of the filtration membrane is less than the above-mentioned range, the crude filtrate will not smoothly flow through the filtration membrane due to the filtration membrane. On the contrary, if the above range is exceeded, impurities present in the crude mixture will pass through the filtration membrane, There is a problem.

In particular, in the present invention, it is necessary to strictly control stirring conditions in order to suppress the precipitation of the crude steel mixture as a final product. Because of the characteristics of raw materials, coagulation and dispersion occur simultaneously during mixing and stirring. Therefore, proper regulation of the coagulation and dispersion rate is required through the stirring process. Therefore, a new parameter called Mixing Index was introduced to guarantee the mixing performance in the laboratory even after scaling up.

The Mixing Index is defined as: < RTI ID = 0.0 >

Mixed Index

= (Anchor stirrer uniformity [kW] * Anchor stirrer rotation speed [rpm]) ^ 1/3

  * (Diameter of anchor stirrer / reactor diameter).

As shown, the anchor stirrer uniformity is expressed in kW, and the anchor stirrer rotation speed is expressed in rpm.

In the production of the crude steel mixture for cement concrete according to the present invention, the mixing index is preferably in the range of 0.5 to 6, preferably 0.7 to 4.5, more preferably 1 to 3 in the mixing index. If the mixing index is less than the above range, the coagulation rate of the crude steel mixture is faster than the rate at which the raw material of the crude steel mixture is dispersed, so that the crude steel mixture is formed into large particles, and the large particles thus formed cause problems such as precipitation and performance deterioration. On the other hand, if the mixing index exceeds the above range, the coagulation speed of the raw material of the crude steel mixture is faster than the coagulation speed of the raw material mixture, so that the coagulation between the raw materials is minimized. Also, the increased agitating force depending on the excess mixing index can cause the life of the stirrer to shorten.

Further, the crude steel mixture for cement concrete of the present invention is characterized by being produced by the above-mentioned method.

The following examples illustrate the present invention in detail but are not to be construed as limiting the scope of the present invention.

Example

Examples 1 and 2, Comparative Examples 1 and 2: Preparation of crude steel mixture (1)

150 g of calcium acetate was added to 120 g of water and sufficiently stirred to prepare a calcium compound aqueous solution. 80 g of liquid sodium silicate and 40 g of sodium hydroxide (50% aqueous solution) were added to 240 g of water and sufficiently stirred to prepare an aqueous solution of a silicon compound and an alkali metal compound. 50 g of a dispersing agent (Aegis, Korea) and 50 g of water were added to a reaction vessel equipped with an anchor stirrer and a high speed dissolver stirrer and sufficiently stirred to prepare an aqueous dispersant solution. Aqueous solutions of calcium compounds and aqueous solutions of alkaline metal compounds were added dropwise (Examples 1 and 2) or dropwise (Comparative Examples 1 and 2) on a high-speed dissolver stirrer, It was added dropwise for 3 hours. After the aqueous solution was added dropwise, stirring was continued for 4 hours to prepare a crude steel mixture for cement concrete of the present invention. Specifically, the reactor was 29 cm in diameter, the diameter of the anchor stirrer was 12 cm, the rotation speed of the anchor stirrer was 500 rpm, and the motor connected to the anchor stirrer was 50 W.

For each example, the extent of precipitation was measured as follows:

① The prepared crude mixture was injected into a 10 ℓ vessel,

② Measure the height of the crude steel mixture in the vessel,

③ Measure the height of the sediment on the floor after a certain period of time.

The sedimentation rate was calculated by the following equation (1).

[Equation 1]

Comparative Example 3: Preparation of crude steel mixture (2)

The same procedure as in Example 1 was followed. The crude steel mixture for cement concrete of the present invention was prepared using a paddle type stirrer in place of the anchor type stirrer, and the degree of precipitation was measured.

Examples 6 to 9: Preparation of crude steel mixture (3)

The crude steel mixture prepared in Example 1 was subjected to a dispersion process in a bead mill (1 L) filled with 0.8 mm beads as shown in Table 3 below to prepare a crude steel mixture for cement concrete of the present invention, Table 3 shows the results.

Comparative Examples 5 and 6: Preparation of crude steel mixture (4)

The same procedure as in Example 1 was carried out. After the aqueous solution of the dispersant, the silicon compound and the aqueous solution of the alkali metal compound were fed into the reaction vessel, and the calcium compound aqueous solution was added dropwise to the reaction vessel for 5 hours (Comparative Example 5) (Comparative Example 6), the crude steel mixture for cement concrete of the present invention was prepared, and the extent of precipitation was measured. The results are shown in Table 4 below.

Example 12: Preparation of crude steel mixture (5)

The same procedure as in Example 1 was carried out. The diameter of the reactor was 2 m, the diameter of the anchor stirrer was 1 m, the rotating speed of the anchor stirrer was 80 rpm, and the motor connected to the anchor stirrer was 1.5 kW. The degree of precipitation of the crude steel mixture for cement concrete according to the present invention after 1 day was 0%.

Production Examples 1 to 6: Preparation of Cement Mortar

Cement mortars were prepared with the mixing ratios shown in Table 4 below (water reducing agent: Aegis, Korea).

Test Example 1: Compressive strength change of cement mortar according to addition amount and curing temperature

The compressive strength of the cement mortar prepared in Preparation Examples 1 to 6 was measured according to the addition amount of the crude steel mixture and the temperature. The measurement was carried out after curing at a temperature of 10 ° C and 20 ° C and a relative humidity of 60% for 24 hours, and the results are shown in Table 5.

The results of Test Example 1 show that when the amount of cement is the same, a higher early compression strength value is obtained by adding the crude steel mixture of the present invention.

Production Examples 7 to 10: Preparation of cement concrete

The cement concrete was prepared at the mixing ratio shown in Table 6 below (water reducing agent: Aegis, Korea).

Test Example 2: Compressive strength change of cement concrete according to addition amount and curing temperature

The compressive strength of the cement concrete prepared in Preparation Examples 7 to 10 was measured according to the addition of the crude steel mixture. The measurement was performed after curing at a temperature of 20 ° C and 50 ° C and a relative humidity of 60%, and the results are shown in Table 4.

The results of Test Example 2 show that when the amount of cement is the same, a premature compression strength value is obtained by adding the crude steel mixture of the present invention.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course it is possible. Accordingly, the scope of the present invention should not be construed as being limited to the above-described embodiments, but should be determined by equivalents to the claims, as well as the claims of the following.

1: Anchor type stirrer
2: dissolver type stirrer

Claims (9)

delete delete delete delete (A) 100 parts by weight of a calcium compound selected from the group consisting of calcium oxide, calcium hydroxide, calcium carbonate, calcium formate, calcium acetate, calcium sulfate and mixtures thereof,
Mixing 40 to 100 parts by weight of water to prepare an aqueous calcium compound solution;
(B) per 100 parts by weight of the calcium compound,
10 to 70 parts by weight of a silicon compound selected from the group consisting of silicon dioxide, silica fume, sodium silicate, potassium silicate, water glass, aluminum silicate, calcium silicate, fly ash, bottom ash,
10 to 70 parts by weight of an alkali metal or alkaline earth metal compound selected from the group consisting of nitrates, formates, nitrates, nitrates, sulfates, thiosulphates, carbonates, chlorides, halides and mixtures thereof of alkali metals or alkaline earth metals,
Mixing 60 to 200 parts by weight of water to prepare a silicon compound and an aqueous solution of an alkali metal or alkaline earth metal compound;
(C) per 100 parts by weight of the calcium compound,
5 to 60 parts by weight of a dispersant, and
Mixing 10 to 30 parts by weight of water to prepare an aqueous solution of a dispersant; And
(D) dropping the aqueous solution of the calcium compound, the silicon compound and the aqueous solution of the alkali metal or alkaline earth metal compound into the aqueous solution of the dispersing agent,
In step (D), the calcium compound aqueous solution is added dropwise for 1 to 6 hours,
In the step (D), the silicon compound and the aqueous solution of the alkali metal or alkaline earth metal compound are added dropwise for 1 to 8 hours,
In the step (D), the reaction tank is maintained at 10 to 60 DEG C,
The step (D) is carried out in a reactor equipped with an anchor stirrer and a dissolver stirrer,
The reaction tank has 2 to 4 dissolver type stirrers,
The dissolver-type agitator is characterized in that the flow rotating about the rotation axis is superior to the flow parallel to the rotation axis,
In step (D), an aqueous solution of a calcium compound, a silicon compound, and an aqueous solution of an alkali metal or an alkaline earth metal compound are added dropwise to the impeller of the dissolver-
After step (D) above,
Further comprising holding the crude mixture for cement concrete for 10 to 60 占 폚 for 0.5 to 12 hours,
After step (D) above,
Further comprising a dispersion treatment step of passing the crude steel mixture for cement concrete through a bead mill,
The bead average particle diameter of the bead mill is 0.3 to 0.8 mm,
The beads of the bead mill are selected from the group consisting of ceramics such as zirconia and alumina, glass, aluminum alloys, and mixtures thereof,
After step (D) above,
Further comprising filtering the crude steel mixture for cement concrete,
The average pore size of the filtration membrane in the filtration is 0.5 to 5 mu m,
The solid content of the crude steel mixture for cement concrete is 20 to 60% by weight,
Per 100 parts by weight of the calcium compound,
0.1 to 5 parts by weight of an antifoaming agent, and
0.1 to 1 part by weight of a thickener,
Wherein the stirring of the crude steel mixture for cement concrete is performed within a mixing index range of 1 to 3. 5. A method for producing a crude steel mixture for cement concrete,
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