KR101561003B1 - Cement composition having self-exothermic slag, cold weather concrete composition having the same, and construction method for structure using the same - Google Patents

Abstract

Disclosed are a cement composition having self-exothermic slag, a cold weather concrete composition having the same, and a method for constructing a structure using the same. The cement composition may include: self-exothermic slag containing C_3A(3CaO·Al_2O_3) as the main mineral, and at least 20 wt% of Al_2O_3; cement; and gypsum.

Description

TECHNICAL FIELD The present invention relates to a cement composition containing self-heating slag, a cold-weathered concrete composition including the same, and a method of constructing a structure using the same. BACKGROUND ART Conventionally,

The present invention relates to a cement material for cold-weathered concrete in the winter season, and more particularly, to a cement composition using self-heating property of self-heating slag to prevent initial frost damage and improve strength, To an extreme environment cement material.

The importance of construction air is always emphasized at the construction site, and various construction technologies and new materials are constantly being demanded. Especially, considering that the winter of the Korean peninsula is getting longer due to global warming and the average daily temperature in winter is getting lower, it is becoming a very important issue for the construction of Korea during the year.

Herein, the term "concrete" is defined as "concrete to be applied when there is a fear that the concrete will freeze during the curing period after pouring the concrete" according to the reinforced concrete construction of the standard specification of the building construction standard.

A study on the cold-weather concrete used for concrete work in winter can be divided into the study on the manufacturing technique of cold-water concrete and the method of heating and heating curing. It is a general method to increase the temperature of concrete by heating water and aggregate, and a method to make curing proceed without freezing of a considerable amount of water below freezing temperature by using cold accelerator. As the heating and heating curing method, there is a heat insulation curing method in which heating is performed by supplying a heat source such as a jet heater or lignite, or heating is performed by using a hot wire.

However, these methods cause various social costs such as quality deterioration, air delay and construction cost increase due to uneven supply of energy use and heat source. In addition, research on the source materials of cement itself is still insufficient. In most construction sites, only Portland cement is usually used.

On the other hand, in order to secure the stability and high durability of the winter structure, more detailed and rigid construction materials are required at the beginning of the construction stage. The concrete is basically the hydration reaction of water and cement materials, and the temperature of the initial concrete is very important because hydration heat is generated and hardened by hydration reaction. If the temperature is lowered early in the construction (below 4 ℃ per day), it may cause damage to the concrete in the early frost damage and hardening of the concrete due to the delay of hardening.

Therefore, if the cement composition, which is the source of the strength of the concrete in the cold concrete construction in winter, is heated, it can minimize the initial damage and can contribute to the stability and durability of the concrete in the long term.

As related prior arts, there have been disclosed a method of preparing a cement paste composition by using a cement paste as disclosed in Patent Registration No. 10-01339294 (entitled " Cold Cement Curing System, published on Dec. 10, 2013) and Published Japanese Patent Application No. 10-2013-0001388 A method for producing a heat-generating slag using slag, a heat-generating mortar and a heat-generating concrete including the heat-generating slag and the heat-generating slag thus produced, published on Jan. 04, 2013).

The inventor of the present invention not only minimizes the above-described damage caused by the initial frost damage if the cement composition, which is the source material of the concrete in the extreme environment at low temperatures, particularly in the coldest temperatures in the winter season, is heated, And durability can be secured.

Accordingly, it is an object of the present invention to provide a cement composition and / or a cold-weather concrete composition capable of achieving a predetermined initial compressive strength by preventing the initial frost damage through the application of the high-dispersion cement to the self-heating slag. .

It is another object of the present invention to provide a method for constructing all structures to be carried out in a low-temperature environment by applying the above-mentioned cement composition and / or cold-weather concrete.

According to the present invention, there is provided a self-heating slag comprising C ₃ A ( ₃ CaO 揃 Al ₂ O ₃ ) as a main mineral and containing Al ₂ O ₃ in an amount of 20 wt% or more; cement; And gypsum.

The self-heating slag may comprise 45 to 60 wt% of CaO, 20 to 40 wt% of Al ₂ O ₃ , 2 to 5 wt% of SiO _2, 1 to 5 wt% of Fe ₂ O ₃ , 9 wt%, K ₂ O 0.01 to 0.1 wt%, Na ₂ O 0.01 to 0.1 wt%, and SO ₃ 0.5 to 3% by weight. The self-heating slag as a by-product is preferably discharged from the refining process of the steel making process and a steel-making slag cooling in air, the powder is also a self-heating slag is 4,000 ~ 10,000 cm ² / g range.

The cement is preferably a high-malt cement having a degree of powder ranging from 4,000 to 5,700 cm ² / g. The above-mentioned high-malt cement is preferably provided by pulverizing portland cement.

It is preferable that the gypsum is at least one selected from the group consisting of natural gypsum, type III anhydrous gypsum, type II anhydrous gypsum, diatomite gypsum, semi-gypsum, desulfurized gypsum, phosphate gypsum and neutralized gypsum.

Wherein the cement composition contains 5 to 30% by weight of self-heating slag, based on 100% by weight of the total; 60 to 90% by weight of high-mallein cement; And 1 to 15% by weight of gypsum.

The above objects are also achieved by a cement composition according to the present invention, aggregate; And a water content.

Furthermore, the above object can be achieved by a method of constructing a structure using a cement composition or a concrete composition according to the present invention, the method comprising:

The present invention can achieve an initial compressive strength capable of withstanding the initial frost damage in cold-water concrete construction by applying a self-heating slag that activates the reaction of the entire composition with a high exothermic reaction and a high- It is possible to improve the durability of the concrete.

FIG. 1 is a graph showing the results of increasing the adiabatic temperature at room temperature (20 ° C) using self-heating slag, ordinary portland cement and high-malt cement.
FIG. 2 is a graph showing the result of increasing the adiabatic temperature at low temperature (-5 ° C) using the ordinary Portland cement, high-malt cement, and the compositions of Examples 1 and 2 and Comparative Example 1, respectively.

Hereinafter, the present invention will be described in detail. In the following description, well-known functions or constructions are not described in order to avoid unnecessary obscuration of the present invention.

If the concrete material is frozen under cold weather conditions in the winter season, there can be serious problems with the quality of the structure concrete. This damage is referred to as 'initial frost damage', which can be defined as the loss of strength, breakage or cracking due to freezing or repeated freezing and thawing at the initial stage of hardening. That is, after the unhardened concrete is frozen at an extremely early stage, the damage of the concrete is remarkable, and if it is damaged, the durability of the concrete is seriously deteriorated and even the concrete is required to be reworked.

Freezing, which has not yet started condensation, and strength at which the initial development of strength is able to withstand the initial frost damage, ie, the lowest compressive strength is generally 5 MPa, even if condensation is completed. In order to solve this problem, water and aggregate are generally heated to promote the hydration reaction of the cement. However, there is a lack of development and attempts to heat the cement composition itself.

The present invention relates to a method for preventing the initial frost damage by exhibiting the required compressive strength without freezing the most important factor in the cold-air concrete construction, and at the same time, And solves the problems.

To this end, the present invention provides a cement composition using the hydration heat characteristic of the self-heating slag and the high-melting cement as a concrete composition, and a construction method using the cement / concrete composition.

More specifically, the self-heating slag employed in the present invention is a calcium-aluminate-based mineral (containing C ₃ A as a main mineral and containing 20 wt% or more of Al ₂ O ₃ ) and exotherm through self- This can promote the overall hydration reaction with mixed high-malt cement. In addition, the calcium-aluminate-based hydrate as a result of the hydration reaction reacts continuously with gypsum, another ingredient, to form a large amount of ettringite. Through this process, additional heat is generated and various hydrates It is possible to expect an effect of improving the durability in the long term by improving the initial strength.

In addition, the self-heating slag is eco-friendly because it is a material capable of reducing the amount of greenhouse gas generation by a substitute amount of cement without requiring a separate firing process.

Hereinafter, the cement composition according to the present invention and the Korean concrete compositions using the same will be described in detail. However, it is not limited by the following chemical composition, and may be modified or optionally mixed as necessary.

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. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

<Cement composition>

Conventionally, the free-CaO content of the steel-making slag is somewhat higher than that of conventional steel-making slag, so the present invention uses the self-heating property of the steelmaking slag as a main component, .

More specifically, the heat-generating cement composition of the present invention comprises: (a) a self-heating slag containing C ₃ A as a main mineral and containing Al ₂ O ₃ in an amount of 20 wt% or more; (b) cement mortar cement; And (c) gypsum.

Here, the calcium-aluminate-based minerals of the self-heating slag (containing C ₃ A as a main mineral and containing 20 wt% or more of Al ₂ O ₃ ) are the fastest and have a high exothermic reaction to activate the overall composition reaction do. Also, mixed cementitious cement has an effect of increasing the initial strength, which produces a large amount of calcium-aluminate-based hydrate, calcium-silicate-based hydrate, ettringite and the like. This series of hydration reactions is very effective in achieving the strength to withstand the initial damping, that is, the minimum compressive strength of 5 MPa.

The first component constituting the cement composition according to the present invention is self-heating slag (a).

The self-heating slag refers to a steel slag that is slowly cooled by a natural cooling method in the air as a by-product discharged during the refining process of the steelmaking process.

The steelmaking slag contains C ₃ A ( ₃ CaO 揃 Al ₂ O ₃ ) as a main mineral and contains Al ₂ O ₃ component in an amount of 20 wt% or more. When these calcium-aluminate-based minerals are hydrated, the hydration reaction of C ₃ S (3CaO · SiO ₂ ) and C ₂ S (2CaO · SiO ₂ ), which are the main minerals of ordinary portland cement, Hydration heat is generated, so that the heat generation characteristic is primarily exhibited. As a result of the hydration reaction, calcium-aluminate-based hydrates such as C ₃ AH ₆ ( ₃ CaO.Al ₂ O ₃ .6H ₂ O) are formed. These calcium-aluminate-based hydrates continuously react with gypsum to form ettringite (Ca ₆ Al ₂ (SO ₄ ) ₃ (OH) ₁₂ · 26H ₂ O) So that the heat generation characteristic is secondarily exhibited. That is, the composition of the present invention comprising self-heating slag and high-malt cement prevents the frost damage at the initial stage of coagulation hardening and reduces the strength of the material due to the hydration reaction under the freezing- Can be promoted.

The self-heating slag may comprise 45 to 60 wt% of CaO, 20 to 40 wt% of Al ₂ O ₃ , 2 to 5 wt% of SiO _2, 1 to 5 wt% of Fe ₂ O ₃ , 4 to 9 wt% of MgO, 0.01 to 0.1% by weight of K ₂ O, 0.01 to 0.1% by weight of Na ₂ O, and SO ₃ 0.5 to 3% by weight.

The powdery degree of the self-heating slag is not particularly limited, but may be in the range of 4,000 to 10,000 cm ² / g.

The self-heating slag may be used in an amount of 5 to 30% by weight, preferably 10 to 30% by weight, based on the total weight of the cement composition. In the present invention, the self-heating slag positively affects the initial strength development due to heat generation. However, when the content of the self-heating slag exceeds 30 wt% as a component of the cement composition, the self-heating slag itself does not have a high hardening property due to the hydration reaction, And does not help to improve durability.

The second component constituting the cement composition according to the present invention is high-malt cement (b). Such high-malt cement has a higher powder viscosity than conventional Portland cement, and thus serves to accelerate the initial hydration reaction.

More specifically, C ₃ S and C ₂ S contained in ordinary Portland cement are the most important minerals for forming CSH (CaO.SiO ₂ .H ₂ O), which is the final hydrate that exhibits curing properties. They actively participate in the hydration reaction of the self-hardening and mixed self-heating slag, such as latent hydration, and there is a limit to induce rapid hydration reaction in a low temperature environment.

Accordingly, it is another feature of the present invention to use a high-malt cement having a powdery degree higher than that of ordinary Portland cement (3,000 ~ 3,900 cm ² / g). Such high - malt cement can activate the hydration reaction through high specific surface area and can accelerate the hydration reaction even under low temperature environment in the winter season. Therefore, the material contributes greatly to increase the initial compressive strength, and thus it is possible to prevent frost damage at the initial stage of coagulation curing.

The above-mentioned high-malt cement is a fine powder formed by pulverizing one kind of ordinary Portland cement with a high-malt cement, and is not particularly limited as long as it is higher than that of conventional ordinary Portland cement. For example, the powder of the high-malt cement may range from 4,000 to 5,700 cm ² / g, preferably from 4,000 to 5,000 cm ² / g.

The content of the high-malt cement can be in the range of 60 to 90% by weight, preferably in the range of 65 to 85% by weight, based on the total weight of the cement composition.

The third component constituting the cement composition according to the present invention is gypsum (c).

The gypsum may be any conventional gypsum composition known to those skilled in the art without limitation. Examples of the gypsum that can be used include natural gypsum, type III anhydrous gypsum, type II anhydrous gypsum, hydrous gypsum, Phosphoric acid gypsum, neutralized gypsum containing quicklime in the phosphate gypsum, or a mixture of at least one of these.

The content of the gypsum may be in the range of 1 to 15% by weight, preferably in the range of 3 to 12% by weight, based on the total weight of the cement composition according to the present invention. Since the gypsum does not have a self-curing property, when the amount of the gypsum exceeds 15% by weight, the content of the cement itself becomes relatively small, so that the curing reaction is not properly performed and the durability is impaired.

In addition to the aforementioned components, the cement composition of the present invention can be used without limitation in the art with conventional additives applicable to cement compositions. For example, the additive may be at least one selected from the group consisting of a dispersant, a preservative, an antirust, a curing agent, a coagulant, an expanding agent, and a defoaming agent.

Here, the above-mentioned dispersing agent, the preservative, the rust inhibitor, the curing agent, the coagulant, the swelling agent, the defoaming agent and the like can be used without limitation, and the use amount thereof is not particularly limited.

&Lt;

The concrete according to the present invention is characterized by exhibiting a compressive strength of not less than 5 MPa within 72 hours of curing in a low-temperature environment of not more than room temperature, especially not more than 4 占 폚, thereby preventing initial corrosion.

For this purpose, the above-described cement composition includes the above-mentioned cement composition, and further comprises aggregate and / or compounded water.

The aggregate may be sand, gravel or the like commonly used in the art. The concrete composition of the present invention may be freely controlled in terms of mixing, thickness, and content of aggregate (sand or gravel) have. The content of the compounding water can also be appropriately controlled.

In addition, the concrete composition of the present invention can use additives commonly used in conventional concrete such as flocculants, curing agents, curing accelerators, curing retardants, swelling agents, and water reducing agents without limitation.

<Construction method of structure>

Further, the present invention provides a method of constructing a structure using the above-mentioned cement composition or concrete composition.

Here, the construction of the structure generally means not only the construction, maintenance and reinforcement of a general structure or structure but also construction, maintenance, and reinforcement of a building or structure in a low temperature environment at room temperature and below 4 ° C.

More specifically, the construction of the structure may include construction, maintenance, and reinforcement of a building or structure such as a house, a school, a building, an apartment, or the like; Construction, maintenance and reinforcement of roads and railways; Repair, and reinforcement of dams, piers, tunnels, and the like, as well as construction, repair, and reinforcement methods of buildings or structures of all construction sites to which cement compositions or concrete compositions are applied .

In particular, in the construction of the structure, the concrete composition of the present invention may be used for the expansion and contraction of the building or structure, and a cement composition may be used for repair and reinforcement.

The method of constructing the structure is not particularly limited and can be applied to various construction fields to which the conventional cement mortar or concrete is applied by the same method. Especially, if the cement mortar or concrete construction needs to be performed in a short time within the sub-zero-winter environment, the effect may be more significant.

Hereinafter, examples and comparative examples of the present invention will be described in more detail. It will be apparent to those skilled in the art that these embodiments are provided by way of illustration only for the purpose of more particularly illustrating the present invention and that the scope of the present invention is not limited by these embodiments .

[ Reference Example ]

Tables 1 and 2 below show an exemplary composition of the materials that can be included in the cement composition and the heavy concrete composition of the present invention and physical properties of the processed materials, respectively. Tables 1 and 2 are the same as the composition and physical properties of the composition provided in the present invention.

Furtherance(%) Ig-Loss SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ CaO MgO SO ₃ f-Cao Slag ¹ 0.8 3.66 33.22 2.88 48.89 5.30 0.00 3.06 Cement ² 1.98 21.59 4.68 3.41 62.39 2.51 2.06 0.21 Burial Mound ³ 1.37 21.16 4.77 3.39 62.06 2.65 3.26 0.08 ¹ Self-heating slag; ² ordinary Portland cement; ³ tombstones cement

importance Powder (cm ² / g) Residue (%) Slag ¹ 2.82 5000 28.5 Cement ² 3.15 3400 7.5 Burial Mound ³ 3.12 4200 2.7 ¹ Self-heating slag; ² ordinary Portland cement; ³ tombstones cement

[ Example  1 to 2 and Comparative Example  1]

Table 3 shows the compounding ratios of the cement composition samples of Examples 1 and 2 and Comparative Example 1, respectively.

combination Composition (% by weight) Comparative Example 1 (Formulation 1) Example 1 (Formulation 2) Example 2 (Compound 3) Self-heating slag 15 15 29 Tombstones 85 77 61 gypsum - 8 10 total 100 100 100

[ Experimental Example  One. Self-heating  Characteristic evaluation]

Mortar was prepared in accordance with KS L ISO 679 (Cement Strength Test Method) as the basic test for confirming self-heating ability which is the most important factor in the present invention, and the insulation temperature (ACM-202L-6F of Tokyo Rico Inc.) Respectively.

Here, the temperature start was divided into a normal temperature condition of 20 ° C and a special environment condition of minus 5 ° C in the winter season, and the analysis condition was 1 minute interval.

&Lt; Result of single temperature rise of raw materials at room temperature >

For the measurement of the heat generated in the hydration reaction, the self-heating slag, the ordinary portland cement and the high-malt cement used in the present invention were respectively prepared at the same conditions of 20 ° C, and their single temperatures were respectively evaluated. And Fig.

Composition Adiabatic temperature rise test (℃) material Immediately after the mixer One day 2 days 3 days Self-heating slag 20 47.7 64.2 65.5 66.0 Usually Portland Cement 20 22.4 56.1 63.5 63.8 Tombstones 20 24.0 63.0 66.3 66.3

Commonly used ordinary Portland cement showed a material temperature of 20 ° C and a temperature of 22.4 ° C just after the mixer, and it rose by 2.4 ° C. In addition, it was confirmed that the high - molecular - weight cement obtained by pulverizing portland cement had a higher hydration reaction temperature than ordinary portland cement because it was increased to 4 ℃ by 24.0 캜.

On the other hand, the self - heating slag was 47.7 ℃ immediately after the mixer, and it was confirmed that the material rises to 27.7 ℃ at 20 ℃, which is higher than ordinary Portland cement and high - malt cement by 20 ℃ or more.

As a result, it was found that the self-heating slag> high-malt cement> ordinary Portland cement can be expressed by listing the heat-up temperature rise curve generated by the hydration reaction at the starting temperature of 20 ° C in order of temperature (see FIG. 1 and Table 4) .

<- At 5 ° C  Result of adiabatic temperature rise>

Table 5 and Fig. 2 below show the result of evaluating the increase of the adiabatic temperature at a temperature start condition of minus 5 캜. At this time, for the accurate test under the cold environment at the subzero temperature, the mixed water was used as a general agitation agent, and the material and the measurement container were prepared and stored for 24 hours or more at -5 ° C in a thermo-hygrostat before testing .

Composition Adiabatic temperature rise test (℃) material Immediately after the mixer One day 2 days 3 days Usually Portland Cement -5 1.9 19.7 30.5 35.7 Tombstones -5 2.2 29.2 37.9 40.3 Comparative Example 1 (Formulation 1) -5 4.6 41.9 46.4 47.2 Example 1 (Formulation 2) -5 2.7 43.4 47.0 47.5 Example 2 (Compound 3) -5 2.9 39.7 44.1 45.4

The rising temperature of Comparative Example 1 (Mixing 1) was the highest at the temperature immediately after mixing the material of -5 ° C and -5 ° C, and then the temperature of Example 2 (Mixing 3) and Example 1 2).

(Example 2)> Formulation 1 (Comparative Example 1)> Formulation 3 (Example 2)> Toluene-modified cement> Moderate portland cement was observed in the order of temperature rise curve after one day , And it was confirmed that the blending of the self-heating slag with the general cement showed a result as high as about 20 ° C.

The temperature difference between the self heating slag and the ordinary portland cement was about 8 ° C at room temperature (20 ° C) after 1 day. In contrast, the self heat generation slag Of Comparative Example 1, Examples 1 to 2 containing 15% or more of Portland cement and ordinary Portland cement showed a result of about 20 캜 higher.

The above-mentioned temperature expression results show that the self-heating slag of the composition of the present invention has a heating effect that raises the temperature, which is higher than that of conventional Portland cement and the cement obtained by crushing it with a high-malt paste . Especially, it showed excellent results even under extreme conditions of sub - zero, especially in the first day of hydration.

[ Experimental Example  2. Evaluation of compressive strength under low temperature environment]

As a basic test to examine whether the composition of the present invention can exhibit excellent strength under low temperature environment, mortars were prepared according to KS L ISO 679 (Cement Strength Test Method) ° C, -5 ° C). The results are shown in Tables 6 to 8 below.

For accurate experiments, all temperature conditions were compared with those of the same material by using a thermo-hygrostat, keeping the material and measurement container 24 hours before the test date. This test is a result of comparing and evaluating more than 3 times.

&Lt; Evaluation test of compressive strength of mortar at room temperature at 20 캜 >

Composition Compressive strength (MPa) 3 days 7 days 28th Usually Portland Cement 32.3 42.9 51.3 Tombstones 39.3 48.0 58.5 Comparative Example 1 (Formulation 1) 20.3 29.9 41.0 Example 1 (Formulation 2) 36.1 41.3 48.2 Example 2 (Compound 3) 34.7 45.1 47.1

Table 6 shows the compressive strength results at 20 ° C, and the best material was high-malt cement. The cement mortar cement exhibited excellent results over all periods of curing, and Comparative Example 1 (Formulation 1) showed the lowest results. Examples 1 and 2 (Formulations 2 to 3) containing 15% or more of self-heating slag and containing a part of gypsum were evaluated to have an initial strength enhancement effect by showing excellent strength for 3 days than ordinary portland cement. The strength after 28 days was lower than that of normal Portland cement, and it was confirmed that the composition of Example 1 (Compound 2) was the most excellent among the compositions applied to the present invention.

&Lt; Evaluation test of compressive strength of room temperature 2 캜 mortar>

Composition Compressive strength (MPa) 3 days 7 days 28th Usually Portland Cement 13.6 25.0 40.0 Tombstones 17.3 30.5 49.3 Comparative Example 1 (Formulation 1) 6.9 16.7 25.5 Example 1 (Formulation 2) 18.9 30.0 39.7 Example 2 (Compound 3) 18.7 28.8 37.5

Table 7 shows the results of compressive strength at 2 ° C, and the best material was as high-malt cement as at 20 ° C, and the lowest result was evaluated as Comparative Example 1 (Formulation 1). It was confirmed that excellent results were obtained by comparing Examples 1 and 2 (Formulations 2 to 3) containing the self-extinguishing slag with each of the 20 ° C results. The results were generally higher than Portland cement for 3 or 7 days. The 28 day strength appeared similar to Portland cement.

&Lt; Evaluation test of compressive strength of -5 deg. C mortar &

Composition Compressive strength (MPa) 3 days 7 days 28th Usually Portland Cement 3.1 11.3 28.1 Tombstones 5.8 18.9 34.7 Comparative Example 1 (Formulation 1) 4.7 15.2 24.0 Example 1 (Formulation 2) 9.5 22.7 37.1 Example 2 (Compound 3) 10.0 22.6 32.0

Table 8 shows the compressive strength at -5 deg. C and the best material was Example 1 (formulation 2) containing self-heating slag. More specifically, in Examples 1 and 2 (Formulations 2 to 3), the result was three times higher than that of ordinary Portland cement in three days strength, and about two times higher in seven days. 28 day strength, and the result of Example 1 (Formulation 2) was higher than that of the cement mortar cement.

From the above-described results of the compressive strengths according to the temperature conditions, it was confirmed that the self-heating slag mixed with the components of the mortar and concrete composition according to the present invention exerts better results than the normal room temperature in the low temperature range. This means that the hydration of the entire composition is accelerated due to the relatively high heat generated by the hydration reaction of the self-heating slag. Especially, in the extreme environments of low temperature and subzero temperature, the characteristics are superior to the conventional ordinary portland cement and high- appear. This means that the above-described composition can be used as a more specialized cement composition and / or a cold-weather concrete material that prevents frost damage and improves strength at the early stage of curing hardening under cold-freezing temperatures.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being the intrinsic features of the invention, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

Claims (7)

Self-heating slag containing C ₃ A ( ₃ CaO · Al ₂ O ₃ ) as major minerals and containing Al ₂ O ₃ in an amount of 20 wt% or more;
cement; And
Gypsum,
The self-heating slag may comprise 45 to 60 wt% of CaO, 20 to 40 wt% of Al ₂ O ₃ , 2 to 5 wt% of SiO _2, 1 to 5 wt% of Fe ₂ O ₃ , 4 to 9 wt% of MgO, 0.01 to 0.1% by weight of K ₂ O, 0.01 to 0.1% by weight of Na ₂ O, and 0.5 to 3% by weight of SO ₃ .
delete The method according to claim 1,
The self-heating slag is a steelmaking slag cooled in air as a by-product discharged in the refining process of the steelmaking process,
And the powdery degree of the self-heating slag is in the range of 4000 to 10,000 cm ² / g.
The method according to claim 1,
The cement is a high melting cement having a degree of powder ranging from 4,000 to 5,700 cm &lt; ² &gt; / g,
Wherein the high-malt cement is usually provided by milling Portland cement.
The method according to claim 1,
Wherein the cement composition contains 5 to 30% by weight of self-heating slag, based on 100% by weight of the total; From 60 to 90% by weight of a high-malleability cement having a degree of powder ranging from 4,000 to 5,700 cm ² / g; And 1 to 15% by weight of gypsum.
A cement composition according to claim 1; aggregate; And a mixed water.
A method of constructing a structure using a cement composition or a concrete composition, the method comprising applying the cement composition of claim 1 or the cement composition of claim 6.

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