WO2018079868A1 - Low-shrinkage and low-carbon green cement composition comprising carbon-mineralized fly ash and early strength type expansion agent, and concrete having same applied thereto - Google Patents

Abstract

One embodiment of the present invention provides a green cement composition comprising Portland cement, carbon minerals, an early strength type expansion agent, and blast furnace slag micropowder. In one embodiment of the present invention: carbon minerals obtained by reacting carbon dioxide, which is a main cause of greenhouse gas, with cogeneration plant fly ash are used, and thus the green cement composition has an effect of better reducing the amount of carbon dioxide than a conventional green cement, which has a simple mixture of fly ash and blast furnace slag micropowder; the cogeneration plant fly ash, which was restricted when used as a concrete admixture because of a high content of free lime, can be effectively utilized; and early strength deterioration and drying shrinkage, which are problems of the conventional green cement, are reduced using the early strength type expansion agent.

Description

Low shrinkage low carbon green cement composition containing carbon mineralized fly ash and crude expansion material and concrete using the same

The present invention relates to a green cement composition comprising carbon mineralized fly ash and a crude expandable material, and concrete including the same. More specifically, the present invention relates to a carbon cement produced by reacting carbon dioxide, a major greenhouse gas, with fly ash from a cogeneration plant. Characterized in that, when applied to concrete, low carbon dioxide generation, low shrinkage low carbon green cement composition that improves the initial strength and improved drying shrinkage and concrete applied thereto.

As of 2013, total greenhouse gas emissions in Korea were about 2.6 billion tons (about 37%) in the power generation sector, 250 million tons (about 36%) in the industrial sector, about 0.9 billion tons (about 13%) in the transportation sector, and about 100 million in other sectors. A total of about 700 million tons of tonnes (about 14%). In terms of greenhouse gas emissions in the industrial sector, steel is about 131 million tons (45%), petrochemicals are about 0.71 billion tons (about 28%), cement is about 0.41 billion tons (about 16%), and other about 0.25 billion tons (about 11%) is occurring. In addition, domestic greenhouse gas emissions are projected to be about 250 million tons in 2030.

Therefore, the government has set domestic greenhouse gas reduction target of 37% by 2030, and various policies and efforts are underway to reduce greenhouse gas throughout the industry.

Since the cement industry is a representative industry that emits representative greenhouse gases along with the steel and petrochemical industries, efforts to reduce greenhouse gases are urgently needed. Cement is an essential material for producing concrete, which is a representative material of construction materials. However, since cement is calcined at a high temperature of 1,450 ° C. or higher at the time of manufacture, the energy consumption rate is high, and the decarbonation reaction of limestone, a raw material of cement, generates about 0.8 kg of carbon dioxide, which is the main culprit of greenhouse gases, when producing 1 ton of cement. It is also known that concrete using cement generates about 340 kg of carbon dioxide per tonne.

Recently, the necessity of reducing carbon dioxide, the main culprit of greenhouse gases, has become an important issue throughout the industry. Efforts are being made in the construction sector to reduce carbon dioxide, and one of them is to reduce the amount of cement used in concrete production. Specifically, instead of reducing cement, there is a method of increasing the amount of fly ash and blast furnace slag powder (Korea Patent Publication No. 10-2013-0020984), and a stimulant is applied to the fly ash or blast furnace slag powder which does not use cement at all. There is a cement method to add. However, since cement is required to use an expensive stimulant, it is still uneconomical and has not been utilized due to a problem of poor construction. Instead of cement, a method of increasing the amount of fly ash or blast furnace slag powder is mainly used for mass concrete for the purpose of reducing heat of hydration of concrete. If fly ash or blast furnace slag powder is used a lot, it is advantageous in terms of reducing heat of hydration of concrete, but there are disadvantages in initial strength of concrete and drying shrinkage. In addition, substituting fly ash and blast furnace slag powder instead of cement is a method of reducing carbon dioxide, which is the main culprit of greenhouse gases, but in order to drastically reduce carbon dioxide, an active method of using the generated carbon dioxide as a material for construction is needed. .

Meanwhile, as the demand for low calorie coal increases due to deterioration of high calorie supply and demand for power generation fuel, the proportion of cogeneration plants using circulating fluidized bed boilers is gradually increasing. When using a conventional high calorie bituminous coal fly ash generated as a by-product is widely used as a mixed material for concrete. However, ash generated from a cogeneration plant using low calorie bituminous coal has a high initial content of free lime and sulfur oxide, unlike the existing fly ash, and thus is limited in utilization due to high initial reactivity and high calorific value. When ash from a cogeneration plant is used as a mixed admixture for concrete, a new recycling method is needed because problems such as abnormal condensation of concrete, slump reduction and increased use of retardant are caused by high glass lime components.

Furthermore, as the construction structures such as apartments and buildings become higher, the demand for longer life of the structures is increasing. In response to these realistic demands, the Ministry of Land, Transport and Maritime Affairs strengthened the criteria for the determination of crack defects in concrete structures in January 2014 by notifying the investigation of defects in apartment buildings, the method of calculating the repair cost, and the defect determination criteria. Many construction companies are considering the use of shrinkage reducing agents, which are inorganic expansion materials and chemical admixtures, in order to cope with the strengthening of the crack defect criteria of concrete structures. However, calcium sulfoaluminate, which is widely used as an inorganic expander, is expensive because it is imported from foreign countries, and a shrinkage reducing agent, which is a chemical admixture, is not only expensive but has not yet been used due to insufficient verification.

The present invention is to solve the above-mentioned problems of the prior art, low-shrink low-carbon green cement that reduces the high carbon dioxide generation of the existing general cement composition, when used as a binder for concrete, improves the initial strength and the dry shrinkage It is an object to provide a composition.

In addition, by using carbon mineral stabilized by reacting carbon dioxide which is a major factor of greenhouse gas with carbon dioxide, which is a high content of free lime generated in cogeneration plant, as a raw material of low shrinkage low carbon green cement, it is aimed to drastically improve the reduction of carbon dioxide in cement. It is done.

Furthermore, it is an object of the present invention to improve the occurrence of cracks due to the decrease in the initial strength and the increase in the shrinkage caused when using the cement-based expansion material as a raw material for the cement composition.

In order to achieve the above object, an aspect of the present invention,

Portland cement; Carbon minerals; Crude expansion material; And it provides a green cement composition, comprising a blast furnace slag fine powder.

In one embodiment, the green cement composition, 15 to 85 parts by weight of Portland cement; 5 to 20 parts by weight of carbon minerals; 5 to 15 parts by weight of the crude expandable material; And blast furnace slag fine powder 5 to 50 parts by weight; may be configured to include.

In one embodiment, the carbon mineral may be formed by reacting fly ash of a cogeneration plant including glass lime with carbon dioxide.

In one embodiment, the carbon mineral, the glass lime content may be 0.1 wt% to 5 wt%.

In one embodiment, the crude steel expandable material may be one selected from the group consisting of a calcium sulfoaluminate (CSA) -based expander, a calcium oxide-based expander, and a combination thereof.

In one embodiment, the calcium sulfoaluminate-based expansion material may be formed by firing at least one selected from the group consisting of playing slag, red mud, fly ash, flooring material and a combination thereof at a temperature of 1000 ℃ to 1450 ℃. .

In one embodiment, the calcium sulfoaluminate-based expansion material, 20 to 40 parts by weight of calcium sulfoaluminate, the powder may be 3500 cm 2 / g to 5000 cm 2 / g.

In one embodiment, the calcium oxide-based expandable material may be formed by firing at least one selected from the group consisting of limestone, desulfurized gypsum, phosphate gypsum and combinations thereof at a temperature of 1000 ° C to 1450 ° C.

In one embodiment, the calcium oxide-based expansion material, 20 to 40 parts by weight of calcium oxide, the powder may be 3500 cm 2 / g to 5000 cm 2 / g.

In addition, in order to achieve the above object, another aspect of the present invention,

The green cement composition, water, fine aggregate, coarse aggregate, including the green concrete is provided.

In one embodiment, the concrete, 10 to 20 parts by weight of the green cement composition; 1 to 10 parts by weight of the water; 30 to 50 parts by weight of the fine aggregate; And 30 to 45 parts by weight of the coarse aggregate; provides a green concrete characterized in that it is blended.

According to an aspect of the present invention, by utilizing carbon minerals reacting carbon dioxide, the main culprit of greenhouse gases, with cogeneration plant fly ash, there is an effect of reducing the amount of carbon dioxide more than green cement simply mixed with existing fly ash or blast furnace slag powder. In addition, the cogeneration plant fly ash, which was constrained as an admixture for concrete due to the high glass lime content, can be effectively utilized. Furthermore, by using the crude steel expansion material there is an effect of reducing the early strength degradation and drying shrinkage that is a problem in the existing green cement.

The effects of the present invention are not limited to the above-described effects, but should be understood to include all the effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a diagram schematically showing a crack suppression mechanism by the expander.

Figure 2 is a graph showing the expansion ratio of the age according to the calcium sulfo aluminate-based expansion material replacement rate.

Figure 3 is a graph showing the compressive strength against the age according to the calcium sulfo aluminate-based expansion material replacement rate.

Figure 4 is a graph showing the amount of expansion and dry shrinkage of each concrete according to the age in Experimental Example 1 of the present invention.

5 is a graph showing the amount of expansion and dry shrinkage of each concrete according to the age in Experimental Example 2 of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Advantages and features of the present invention, and a method of achieving the same will be apparent with reference to the embodiments described below in detail with reference to the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and are commonly used in the art to which the present invention pertains. It is provided to fully inform the person of knowledge of the scope of the invention. Moreover, the invention is only defined by the scope of the claims.

Furthermore, in the following description of the present invention, if it is determined that related related technologies and the like may obscure the gist of the present invention, detailed description thereof will be omitted.

One aspect of the invention,

Portland cement; Carbon minerals; Crude expansion material; And it provides a green cement composition, comprising a blast furnace slag fine powder.

The green cement composition,

15 to 85 parts by weight of portland cement;

5 to 20 parts by weight of carbon minerals;

5 to 15 parts by weight of the crude expandable material; And

5 to 50 parts by weight of blast furnace slag powder; may be configured to include.

Portland cement is the most commonly used binder in the manufacture of concrete. The main compounds of cement are C3S (3CaO · SiO ₂ ), C2S (2CaO · SiO ₂ ), C3A (3CaO · Al ₂ O ₃ ), C4AF (4CaOAl ₂ O ₃ · Fe ₂ O ₃ ) It is the main compound that controls the action of its main properties such as hydration, condensation, curing.

The cement reacts with water to cause a hydration reaction that produces CSH (calcium silicate hydrate) and calcium hydroxide (Ca (OH) ₂ ), through which coagulation and curing proceed. Typical concrete binder compositions mostly consist only of cement.

In the green cement composition according to an aspect of the present invention, it is preferable that the portland cement has a powder degree of 3000 cm 2 / g to 4000 cm 2 / g.

The portland cement may include 15 to 85 parts by weight of the green cement composition. When the portland cement is included in less than 15 parts by weight, problems may occur in the development of compressive strength, and when the portland cement is included in more than 85 parts by weight, the amount of carbon minerals or blast furnace slag fine powder is relatively small to reduce the effective carbon dioxide. Problems may arise.

In the green cement composition according to an aspect of the present invention, the carbon mineral may be formed by reacting a cogeneration plant fly ash including glass lime with carbon dioxide. Specifically, carbon dioxide may be injected into the mixture in which the fly ash is immersed in water to form a solid phase including carbonate, and the solid phase may be solid-liquid separated and dried at a pH of the mixture of 9 or less to form a carbon mineral.

As shown in Table 1 below, the general fly ash (general FA) used as the admixture for concrete has a low calcium oxide content of 4.52 wt%, but the fly ash (cogeneration FA) generated at the cogeneration plant has a calcium oxide content of 27.69 wt%. Relatively high in%. Since most of the calcium oxide of fly ash generated in the cogeneration plant exists as glass lime, it reacts immediately when it comes into contact with water, so when used as a mixed material for concrete, abnormal condensation and slump decrease may occur. Cracks may occur due to

FA type	SiO 2	Al 2 O 3	Fe 2 O 3	CaO	MgO	K 2 O	Na 2 O	TiO 2	MnO	P 2 O 5	Ig.loss
General FA	58.12	21.34	6.58	4.52	1.91	1.15	0.24	1.09	0.08	0.31	3.67
Cogeneration FA	34.6	13.71	9.28	27.69	4.8	0.85	0.28	0.89	0.13	0.1	2.73

(In Table 1, the numerical values represent wt% of each component)

In the green cement composition according to an aspect of the present invention, the carbon mineral is 0.2 wt% of free lime by reacting fly ash containing a lot of free lime generated in a cogeneration plant with carbon dioxide, which is a major greenhouse gas generated in an industrial field. % To 5 wt%.

The carbon mineral powder is preferably 4000 cm 2 / g to 6000 cm 2 / g.

The carbon mineral may include 5 to 20 parts by weight of the green cement composition. When the carbon mineral is included in less than 5 parts by weight, there may be a problem that the carbon dioxide reduction rate is significantly reduced, when the carbon mineral is included in more than 20 parts by weight, there is a fear that the strength in the concrete containing it.

Therefore, in consideration of concrete fluidity, compressive strength, carbon dioxide reduction, etc., the carbon mineral is preferably contained in 5 to 20 parts by weight of the green cement composition.

As shown in FIG. 1, since concrete is generally a material having high cracking caused by shrinkage, it is possible to reduce cracking by reducing shrinkage using an expansion material.

In the green cement composition according to an aspect of the present invention, the crude steel expandable material may be one selected from the group consisting of a calcium sulfoaluminate (CSA) -based expander, a calcium oxide-based expander, and a combination thereof.

The calcium sulfoaluminate-based expander may be formed by firing at least one selected from the group consisting of playing slag, red mud, fly ash, flooring, and combinations thereof at a temperature of 1000 ° C to 1450 ° C.

The calcium sulfoaluminate-based expander may include 20 to 40 parts by weight of calcium sulfoaluminate, and the powder may be 3500 cm 2 / g to 5000 cm 2 / g.

The calcium oxide-based expandable material may be formed by firing at least one selected from the group consisting of limestone, desulfurized gypsum, phosphate gypsum and a combination thereof at a temperature of 1000 ° C to 1450 ° C.

The calcium oxide-based expandable material may include 20 to 40 parts by weight of calcium oxide, and the powder may be 3500 cm 2 / g to 5000 cm 2 / g.

The crude steel expandable material may have a powder degree of 3500 cm 2 / g to 5000 cm 2 / g to secure early strength, and may include 5 to 15 parts by weight of the green cement composition. When the coarse expandable material is included in less than 5 parts by weight, a cracking problem may occur during dry shrinkage due to a decrease in the expansion ratio of the concrete including the same, when the coarse expandable material is included in excess of 15 parts by weight, the fluidity of the concrete including the same There exists a possibility that intensity | strength may fall with deterioration, crack generation by overexpansion, and age.

Therefore, in consideration of concrete fluidity, overexpansion, long-term strength, etc., the coarse steel expandable material is preferably included in an amount of 5 to 15 parts by weight in the green cement composition.

Blast furnace slag powder is a by-product produced in the steelmaking process, and is a mixed material for concrete, which is widely used together with general fly ash. Blast furnace slag powder is generally known to increase the long-term strength by densifying concrete structure through the secondary reaction with cement hydrate.

In the green cement composition according to an aspect of the present invention, the blast furnace slag fine powder may have a powder degree of 4000 cm 2 / g to 6000 cm 2 / g.

The blast furnace slag fine powder may be included in the green cement composition 5 to 50 parts by weight. When the blast furnace slag fine powder is included in less than 5 parts by weight, there may be a problem in the long-term compressive strength expression effect, when the blast furnace slag fine powder is contained in more than 50 parts by weight, the strength of the initial concrete using the cement containing the same It may be lowered, there may be a problem that a large amount of dry shrinkage appears.

Green cement composition having the above composition range can reduce the amount of carbon dioxide generated 10% to 30% compared to the cement composition containing a general fly ash. In addition, when it is applied to concrete it can suppress the early drop in strength, minimize the shrinkage during drying, it can exhibit a good compressive strength.

Another aspect of the invention,

The green cement composition, water, fine aggregate, coarse aggregate, including the green concrete is provided.

The concrete,

10 to 20 parts by weight of the green cement composition;

1 to 10 parts by weight of the water;

30 to 50 parts by weight of the fine aggregate; And

30 to 45 parts by weight of the coarse aggregate; may be combined to include.

Green concrete having the above composition range can suppress the premature strength decrease, minimize the shrinkage during drying, and can exhibit good compressive strength.

Green concrete having the above composition range can reduce the amount of carbon dioxide generated 10% to 30% compared to the concrete containing the general fly ash.

Hereinafter, the comparison of the high carbon dioxide capacity before and after the carbon mineralization (carbonization) of fly ash, the mortar characteristics according to the carbon mineral content, the cement characteristics according to the calcium sulfoaluminate-based expander content and the cement characteristics according to the calcium oxide-based expander content.

<Comparison of High Capacity of Carbon Dioxide Before and After Carbon Mineralization of Carbonate Ash>

Table 2 shows the high capacity of carbon dioxide (CO ₂ ) before and after carbon mineralization (carbonization) by type of fly ash.

FA type	Wt% before carbonation	Wt% after carbonation	CO2 high capacity (wt%)	High capacity per kg (kg)
General FA	0.13	0.82	0.69	6.9
Cogeneration FA	4.09	11.28	7.19	71.9

As shown in Table 2, the general fly ash has a low free lime content, resulting in a low carbon dioxide solids content of 0.69%, but the cogeneration plant fly ash has a high free lime content of 7.19%. This implies that 6.9 kg of regular fly ash per tonne can be employed and 71.9 kg of cogeneration fly ash can be employed, thus confirming that cogeneration fly ash can employ carbon dioxide about 10 times higher than ordinary fly ash. .

Mortar Characteristics According to Carbon Mineral Content

Basic mortar including 300 parts by weight of sand and 50 parts by weight of water was prepared based on 100 parts by weight of Portland cement. Subsequently, 5 parts by weight and 10 parts by weight of the mortar including cogeneration plant fly ash, which was replaced by 5 parts by weight and 10 parts by weight, of the base mortar, respectively, were mixed. Mortars containing carbon minerals (carbon mineralization of the cogeneration plant fly ash) were blended, and the characteristics of the mortars are shown in Table 3.

Mortar Characteristics According to Carbon Mineral Content

Basic mortar including 300 parts by weight of sand and 50 parts by weight of water was prepared based on 100 parts by weight of Portland cement. Subsequently, 5 parts by weight and 10 parts by weight of the mortar including cogeneration plant fly ash, which was replaced by 5 parts by weight and 10 parts by weight, of the base mortar, respectively, were mixed. Mortars containing carbon minerals (carbon mineralization of the cogeneration plant fly ash) were blended, and the characteristics of the mortars are shown in Table 3.

Cement substitute,% substitution	Initial flow (mm)	60 minutes flow (mm)	First minute	Termination (minutes)	Daily Compressive Strength (MPa)	3-day compressive strength (MPa)	7 Day Compressive Strength (MPa)	21-day compressive strength (MPa)
General FA, 5%	212	192	230	320	15.7	37	45.5	60.3
General FA, 10%	213	184	280	370	8.6	36	46	57.4
Cogeneration FA, 5%	202	175	130	250	19.7	38.7	48.3	62
Cogeneration FA, 10%	197	165	140	190	13.3	37.8	46.3	60.3
Carbon mineral, 5%	205	185	210	310	18.2	37.7	47.4	61
Carbon mineral, 10%	198	179	270	350	12.9	35.1	45.2	60.8

As shown in Table 3, mortars containing uncarbonated cogeneration plant fly ash exhibited high daily compressive strength due to high glass lime content, but high flow loss due to the initial reactivity of glass lime, resulting in termination of It was confirmed that there was a problem in workability due to the quick setting time.

On the other hand, mortar containing carbon minerals has a good liquidity loss of 60 minutes by carbonizing glass lime of cogeneration plant fly ash with carbon dioxide injection. As a result, the condensation time of termination is similar to that of conventional fly ash used as concrete admixture. have. In addition, the strength of the early age of one day was lower than that of mortars containing non-carbonated cogeneration fly ash, but higher than the mortars containing conventional fly ashes used in conventional concrete admixtures. Therefore, it was confirmed that the carbon mineral obtained by carbonizing the cogeneration plant fly ash can be used as a general fly ash used as a concrete admixture.

<Cement Characteristics by Calcium Sulfoaluminate Expanded Material Content>

A basic cement including 300 parts by weight of sand and 50 parts by weight of water was prepared relative to 100 parts by weight of Portland cement. Then, cement containing 5 parts by weight, 10 parts by weight and 15 parts by weight of the calcium sulfoaluminate-based expansion material was prepared for the portland cement of the basic cement, respectively, and the characteristics of the cements are shown in FIGS. 2 and 3. It was.

As shown in Figures 2 and 3, the amount of expansion of the calcium sulfoaluminate-based coarse-type expansion material increases as the amount of expansion increases from 100% to 180% compared to the base cement, the compressive strength as the amount of use of the expansion material increases It was also confirmed that the 8% to 20% increase.

<Cement Characteristics by Calcium Oxide Expander Content>

A basic cement including 300 parts by weight of sand and 50 parts by weight of water was prepared relative to 100 parts by weight of Portland cement. Then, a cement containing 5 parts by weight, 10 parts by weight, and 15 parts by weight of the calcium sulfoaluminate-based expansion material was prepared for the portland cement of the basic cement, respectively, and the properties of the cements are shown in Table 4 below. .

CaO-based expansion material replacement rate (%)	2 Day Expansion Rate (%)	7-day expansion rate (%)	28-day expansion rate (%)	Initial cement flow (mm	60 minutes cement flow (mm)	Cement cementing (min)	Cement Termination (min)	Daily Compressive Strength (MPa)	7 Day Compressive Strength (MPa)	28 Day Compressive Strength (MPa)
0	0.001	0.006	-0.08	165	55	207	420	14.5	34.8	44.7
10	0.033	0.054	-0.026	174	74	220	400	16.9	39.7	43.1
15	0.043	0.064	-0.014	177	80	203	360	18	39.2	43.4

As shown in Table 4, the expansion rate, fluidity, condensation, and compressive strength characteristics of the cement according to the replacement rate of the calcium oxide-based coarse expandable material were shown. As the replacement rate of calcium oxide-based expander increases, the expansion rate increases, which reduces the shrinkage of 28 days. In addition, the compressive strength of the first day of old age was increased compared to the case of using only cement alone, using a calcium oxide-based coarse expanded material.

Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. However, the following Examples and Experimental Examples are only for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example 1 Concrete 1 Containing Green Cement Composition

70 parts by weight of Portland cement;

5 parts by weight of carbon minerals containing calcium carbonate;

5 parts by weight of calcium sulfoaluminate-based expander; And

It is provided with a cement composition comprising; 20 parts by weight fine slag powder,

The cement composition 340 kg / ㎥, unit quantity of 170 kg / ㎥, fine aggregate 901 kg / ㎥ and coarse aggregate 860 kg / ㎥ was provided with concrete.

Example 2 Concrete 2 Containing Green Cement Composition

In Example 1, the cement composition

60 parts by weight of Portland cement;

10 parts by weight of carbon minerals containing calcium carbonate;

10 parts by weight of calcium sulfoaluminate-based expander; And

20 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 1 was provided with concrete.

Example 3 Concrete 3 Containing Green Cement Composition

In Example 1, the cement composition

60 parts by weight of Portland cement;

5 parts by weight of carbon minerals containing calcium carbonate;

15 parts by weight of calcium sulfoaluminate-based expander; And

20 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 1 was provided with concrete.

Comparative Example 1 Concrete Containing Cement Composition

In Example 1, the cement composition

80 parts by weight of Portland cement; And

20 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 1 was provided with concrete.

<Experiment 1> Comparison of compressive strength of concrete according to the substitution of carbon mineral and crude expansion type cement

Compositions, formulations and compressive strengths of Examples 1 to 3 and Comparative Example 1 are shown in Table 5 and FIG. 4.

division	OPC (wt%)	Slag fine powder (wt%)	Carbon minerals (wt%)	Rough Steel Expansion Material (wt%)	W / B (%)	S / a (%)	W (kg / ㎥)	B (kg / ㎥)	S (kg / ㎥)	G (kg / ㎥)	Daily Compressive Strength (MPa)	3-day compressive strength (MPa)	7 Day Compressive Strength (MPa)	28 Day Compressive Strength (MPa)
Comparative Example 1	80	20			50	51	170	340	901	860	2.7	17.3	24.1	36.4
Example 1	70	20	5	5	50	51	170	340	901	860	3.8	18.8	26.5	39
Example 2	60	20	10	10	50	51	170	340	901	860	2.9	18	24.3	36.6
Example 3	60	20	5	15	50	51	170	340	901	860	3.2	18.3	25.9	38.4

In Table 5, OPC: Falkland cement, W / B: water binder ratio, S / a: fine aggregate ratio, W: unit quantity, B: binder (cement composition) amount, S: fine aggregate, G: coarse aggregate )

As shown in Table 5 and Figure 4, compared to Comparative Example 1, which is a concrete formulation containing a cement (binder) composition commonly used in the field, Examples 1 to 3 are equivalent or more compression, although the amount of cement is relatively reduced. It expresses strength. In addition, compared with Comparative Example 1, Examples 1 to 3 has a large amount of expansion, thereby reducing the dry shrinkage.

Example 4 Concrete 4 Containing Green Cement Composition

30 parts by weight of Portland cement;

20 parts by weight of carbon minerals containing calcium carbonate;

10 parts by weight of calcium sulfoaluminate-based expander; And

40 parts by weight of fine slag powder; provided with a cement composition comprising,

The cement composition 450 kg / ㎥, unit quantity 165 kg / ㎥, fine aggregate 893 kg / ㎥ and coarse aggregate 822 kg / ㎥ was provided with concrete.

Example 5 Concrete 5 Containing Green Cement Composition

In Example 4, the cement composition

25 parts by weight of Portland cement;

15 parts by weight of carbon minerals containing calcium carbonate;

10 parts by weight of calcium sulfoaluminate-based expander; And

40 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 4 was provided with concrete.

Example 6 Concrete 6 Containing Green Cement Composition

In Example 4, the cement composition

20 parts by weight of Portland cement;

15 parts by weight of carbon minerals containing calcium carbonate;

15 parts by weight of calcium sulfoaluminate-based expander; And

40 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 4 was provided with concrete.

Comparative Example 2 Concrete Including Cement Composition

In Example 4, the cement composition

35 parts by weight of Portland cement;

25 parts by weight of fly ash; And

40 parts by weight of fine powder of slag; except that it was included in the same manner as in Example 4 was provided with concrete.

Experimental Example 2 Comparison of Concrete Compressive Strength by Replacing Carbon Minerals and Crude Expandables in Cement 2

Compositions, formulations and compressive strengths of Examples 4 to 6 and Comparative Example 2 are shown in Table 6 and FIG. 5.

division	OPC (wt%)	Slag fine powder (wt%)	Fly ash (wt%)	Carbon mineral (wt%)	Rough Steel Expansion Material (wt%)	W / B (%)	S / a (%)	W (kg / ㎥)	B (kg / ㎥)	S (kg / ㎥)	G (kg / ㎥)	3-day compressive strength (MPa)	7 Day Compressive Strength (MPa)	28 Day Compressive Strength (MPa)	56 day compressive strength (MPa)
Comparative Example 2	35	40	25			36.7	52.6	165	450	893	822	15.2	25.8	41.3	49.1
Example 4	30	40		20	10	36.7	52.6	165	450	893	822	17.2	27.9	47.8	53.3
Example 5	25	40		15	10	36.7	52.6	165	450	893	822	15	28.2	44	51.4
Example 6	20	40		15	15	36.7	52.6	165	450	893	822	14.9	27.2	43.7	50.7

In Table 6, OPC: Falkland cement, W / B: water binder material ratio, S / a: fine aggregate ratio, W: unit quantity, B: binder (cement composition) amount, S: fine aggregate, G: coarse aggregate )

As shown in Table 6 and Figure 5, the compressive strength after the age of 28 days, the Examples 4 to 6 using the low shrinkage low carbon green cement composition expresses the compressive strength equal to or greater than in Comparative Example 2.

Existing concrete used in large mat foundation concrete structures uses blast furnace slag fine powder and fly ash in large quantities to reduce cracks due to hydration heat. Long-term strength after 28 days is more important than initial age strength, and the amount of dry shrinkage may increase due to the use of blast furnace slag fine powder.

Examples 4 to 6 of the present invention, as shown in Figure 6 was shown to occur less dry shrinkage amount of the green cement composition compared to Comparative Example 2.

Experimental Example 3 Comparison of Carbon Dioxide Generation and Reduction Rates of Cement

The amount of CO ₂ generated per 1 ton of the binder of Examples 4 to 6 and Comparative Example 2 and the reduction rate are shown in Table 7 below.

division	OPC (wt%)	Slag fine powder (wt%)	Fly ash (wt%)	Carbon mineral (wt%)	Rough Steel Expansion Material (wt%)	OPC 1 ton of CO 2 generation amount (kg)	Slag per ton of CO 2 generation amount (kg)	CO 2 emissions per tonne of fly ash (kg)	CO 2 emissions per tonne of carbon mineral (kg)	Joganghyeong expandable material per ton of CO 2 generation amount (kg)	Sum	CO 2 reduction rate (%)
Comparative Example 2	35	40	25			304.5	15.1	3.43			323	0
Example 4	30	40		20	10	261	15.1		-11.6	29	293.5	9.13
Example 5	25	40		15	10	217.5	15.1		-8.73	29	252.9	21.7
Example 6	20	40		15	15	174	15.1		-8.73	43.5	223.9	30.7

(1 ton produced when CO ₂ emissions is, OPC (Portland cement): 870, Slag: 37.7, 13.7 fly ash, carbon minerals -58.2, joganghyeong expandable material: 290, and the amount of generated CO ₂ per ton of mineral carbon was 13.7 (ash amount) 71.9 (higher carbonation reaction with CO ₂ ) = -58.2

As shown in Table 7, it was confirmed that the low shrinkage low carbon green cement composition of Examples 4 to 6 can further reduce the CO ₂ generation amount by about 9.13% to 30.7% compared with the existing cement (binder) of Comparative Example ₂ .

So far it has been described with respect to the green cement composition comprising a carbon mineralized fly ash and a crude expansion material according to an aspect of the present invention and a specific embodiment of the concrete applied thereto, without departing from the scope of the present invention It is obvious that the embodiment can be modified.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

In other words, the foregoing embodiments are to be understood in all respects as illustrative and not restrictive, the scope of the invention being indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

Claims (11)

1. Portland cement; Carbon minerals; Crude expansion material; And blast furnace slag fine powder.
2. The method of claim 1,

   The green cement composition,

   15 to 85 parts by weight of portland cement;

   5 to 20 parts by weight of carbon minerals;

   5 to 15 parts by weight of the crude expandable material; And

   The blast furnace slag fine powder 5 to 50 parts by weight; Green cement composition comprising a.
3. The method of claim 1,

   The carbon mineral,

   Green cement composition, characterized in that formed by reacting fly ash cogeneration plant containing glass lime with carbon dioxide.
4. The method of claim 3,

   The carbon mineral,

   Green lime composition, characterized in that the free lime content of 0.1 wt% to 5 wt%.
5. The method of claim 1,

   The steel type expansion material,

   A green cement composition, characterized in that it is one kind selected from the group consisting of a calcium sulfoaluminate (CSA) -based expander, a calcium oxide-based expander, and a combination thereof.
6. The method of claim 5,

   The calcium sulfoaluminate-based expansion material,

   Green cement composition, characterized in that formed by firing at a temperature of 1000 ℃ to 1450 ℃ selected from the group consisting of playing slag, red mud, fly ash, flooring and combinations thereof.
7. The method of claim 5,

   The calcium sulfoaluminate-based expansion material,

   20 to 40 parts by weight of calcium sulfoaluminate, and the powder degree is green cement composition, characterized in that 3500 cm 2 / g to 5000 cm 2 / g.
8. The method of claim 5,

   The calcium oxide expandable material,

   Green cement composition, characterized in that formed by firing at a temperature of 1000 ℃ to 1450 ℃ selected from the group consisting of limestone, desulfurized gypsum, phosphate gypsum and combinations thereof.
9. The method of claim 5,

   The calcium oxide expandable material,

   Green cement composition comprising 20 to 40 parts by weight of calcium oxide, the powder degree is 3500 cm 2 / g to 5000 cm 2 / g.
10. The green concrete composition of Claim 1 mix | blended including water, fine aggregate, and a coarse aggregate.
11. The method of claim 10,

    The concrete,

    10 to 20 parts by weight of the green cement composition;

    1 to 10 parts by weight of the water;

    30 to 50 parts by weight of the fine aggregate; And

    30 to 45 parts by weight of the coarse aggregate; Green concrete characterized in that it is blended.

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