KR20160053387A - Cementless promotion-type admixture, and cementless composition comprising it - Google Patents

Abstract

The present invention relates to an admixture promoting zero cement, comprising a triol group compound and a uncemented composition comprising the same. The triol group compound as an admixture promoting zero cement promotes hardening and induces generation of C-S-H phase which is an important hydration phase for intensity expression by depleting calcium hydroxide in a hardened body. Also, the admixture develops small and dense C-S-H phase, thereby forming hydration phase which is advantageous for intensity expression while enhancing strength of the uncemented hardened body.

Description

[0001] The present invention relates to a cementless promoting type admixture and a cementless composition containing the same,

The present invention relates to a cement-promoting admixture, and more particularly, to a promoting admixture for use in the production of cement using a calcium-based stimulant and a cement composition containing the same.

Carbon dioxide (CO ₂₎ is one of the leading causes of global warming, a type of greenhouse gases. In Korea, 80% of the carbon dioxide is emitted from the energy industry, 24% of which is emitted from buildings. Generally, carbon dioxide is the most common source of building materials in steel and cement. Therefore, various researches are being conducted to develop eco-friendly building materials, especially environment-friendly concrete, which can reduce the amount of carbon dioxide emissions while saving energy.

Concrete is mixed with water by adding aggregate such as sand, gravel, and rebar to cement powder, and then mixed with water, put into a desired model frame, and solidified to obtain a desired structure. Calcium oxide (CaO), which is the main component of cement, is obtained by heating calcium carbonate (CaCO ₃ ) at a high temperature of 1600 ° C. In this process, a large amount of carbon dioxide is generated from the carbon dioxide %, Which is a serious problem.

Environmentally friendly concrete is a concrete produced using environmentally friendly raw materials that reduce environmental pollutants. It is characterized by lower energy consumption and less carbon dioxide emissions than ordinary concrete.

In civil engineering construction, fly ash and granulated blast furnace slag are widely used as cement binders, and many studies have been conducted as raw materials for cement.

In a study to use fly ash or blast furnace slag as a raw material for cement, a strong alkaline stimulant such as potassium hydroxide (KOH) or sodium hydroxide (NaOH) is mainly used for producing cement paste water or cured product . These strongly alkaline stimulants are those in which Na ⁺ ions or K ⁺ ions are directly involved in the burning of water of the cured body to produce uncured cured bodies, and the reactions are rapidly generated due to the strong alkalinity, resulting in problems in workability and difficulties in practical use due to high raw material costs . Further, when a strong alkaline stimulant is used, there is a disadvantage that it is impossible to use a water reducing agent (a chemical admixture for concrete) or the like because the pH is rapidly increased and the reaction occurs rapidly.

In order to solve these problems, researches have been carried out in which a calcium-based irritant such as calcium oxide, calcium hydroxide {Ca (OH) ₂ } or calcium sulfide (CaS) is used instead of a strong alkaline stimulant to secure fluidity and to produce a more stable cured product It is progressing. When a calcium-based irritant is used, it exhibits a stable reaction, securing fluidity and securing time to maintain fluidity. It is also easy to use a water reducing agent and the like, so that it is possible to increase the strength by water reduction.

Circulating Fluidized Bed Combustion (CFBC Ash) is an ash produced in a circulating fluidized bed combustion boiler (CFBC boiler). Since the circulating fluidized bed combustion boiler is a circulating type, CFBC ash is produced at a very low temperature of 850 to 900 ° C, compared to the production temperature of general PC (pulverized combustion) boiler ash of 1200 to 1400 ° C. Since the ash particles do not dissolve at this temperature, the surface shape of the CFBC ash is irregular, unlike the conventional PC boiler ash (refinery), which has a spherical shape due to reduced surface area during melting at high temperature. In addition, since it occurs at a temperature lower than the temperature in the high-temperature molten state, it does not contain amorphous unlike the refining sieves.

In the circulating fluidized bed combustion boiler, the fluidized bed can be made of limestone in order to increase the removal efficiency of sulfur dioxide (SO ₂ ) and nitrogen oxide (NO _x ) during combustion. In the case of using limestone as the fluidized bed, calcium oxide is produced from decarboxylation reaction [CaCO ₃ = CaO + CO ₂ ↑] from limestone (CaCO ₃ ) as a fluidized bed, ₃ ) and the calcium oxide are combined in the boiler to produce calcium sulfate (CaSO ₄ ). Therefore, the main components of most CFBC ash are calcium oxide and calcium sulfate.

1. Korean Patent Publication No. 10-2005-0041439 2. Korean Patent Publication No. 10-2010-0040143 3. Korean Patent Publication No. 10-2010-0126736 4. Korean Patent Registration No. 10-1317647

The object of the present invention is to enhance the strength of the uncured cured body by using a substance having a triol group as a promoting component in an admixture used for water control when calcium stimulants are used in the manufacture of cement.

In order to achieve the above object, the present invention provides a cement-promoting admixture comprising a triol compound.

In the above admixture, the triol compound is preferably triethanolamine, glycerin or a mixture thereof.

Preferably, the admixture further comprises at least one selected from amines, glycerol, and glycols.

The amines are preferably at least one selected from the group consisting of diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, diisopropanolethanolamine and isopropanol diethanolamine.

The glycerin is preferably at least one selected from the group consisting of diglycerin, triglycerin, polyglycerin, phosphoglycerin, diphosphoglycerin and triphosphoglycerin.

Preferably, the glycerin is obtained as a biodiesel by-product.

The glycols are preferably at least one selected from the group consisting of propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol.

The present invention also provides a cement composition comprising a calcium-based stimulant and the promoted admixture, based on blast furnace slag, fly ash or a mixture thereof.

In the above-mentioned composition, the promoting admixture is preferably used in an amount of 0.01 to 50 parts by weight per 100 parts by weight of blast furnace slag, fly ash or a mixture thereof.

In the composition, the calcium stimulant is preferably at least one selected from calcium sulfate, calcium nitrate, calcium silicate, calcium hydroxide, calcium chloride, calcium stearate, calcium metaphosphate, calcium lactate and calcium oxide.

The present invention also provides activated mortar, active concrete comprising the above cement composition.

The present invention also provides a cement product made from the cement composition,

Preferably, the cement product is a brick or block.

The cement-promoting type admixture of the present invention is characterized in that the strength of the cement-hardened material produced by using blast furnace slag, fly ash or a mixture thereof as a raw material and using a calcium-based stimulant to produce a cementless cement is 20 to 60% . This is because when the cesium stimulant is used to make cement, the triol compound added accelerates hardening and calcium hydroxide is consumed so that a CSH phase, which is an important hydration phase, is generated. The CSH phase is small and densely developed, So as to form an advantageous number of images.

Also, when the cement concrete is manufactured, it is possible to reduce the amount of powder at the same strength, thereby reducing the cost.

1A to 1C are electron micrographs showing the shape of each raw material used, wherein FIG. 1A shows blast furnace slag, FIG. 1B shows fly ash, and FIG. 1C shows CFBC ash.
2 is a graph showing the results of X-ray diffraction analysis of cement added with glycerin.
FIGS. 3A and 3B are electron micrographs of cement added with glycerin, FIGS. 3A and 3B are electron micrographs of Comparative Example 2 and Example 3, respectively.
4 is a graph showing the compressive strength according to the content of the triol compound.

Hereinafter, the present invention will be described in detail.

One. Causes  Accelerated admixture

The cement-promoting admixture of the present invention comprises a triol compound and is based on blast furnace slag or fly ash and is used in the manufacture of cement using calcium-based stimulants.

As the triol compound, triethanolamine (TEA), glycerin or a mixture thereof is preferably used as a compound having a triol group at the terminal, which is a typical organic compound having a triol group at the terminal, no. Both compounds are more preferably used in a liquid form having a solid content of 85%. The triol compound improves the strength by accelerating curing when preparing cement using calcium stimulant.

The promoting admixture may further include at least one selected from amines, glycerin and glycols.

As the amines, it is preferable to use at least one selected from diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine (TIPA), diisopropanolethanolamine (EDIPA) and isopropanol diethanolamine Do.

As the glycerin, it is preferable to use at least one selected from among diglycerin, triglycerin, polyglycerin, phosphoglycerin, diphosphoglycerin and triphosphoglycerin. It is particularly preferred to use glycerin which is obtained as a biodiesel by-product.

As the glycols, it is preferable to use at least one selected from among propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol.

2. Causes  Composition

The cement composition of the present invention is based on blast furnace slag, fly ash or a mixture thereof, and includes a calcium-based stimulant and the promoting admixture.

As a raw material for producing cement, it is preferable to use blast furnace slag, fly ash or a mixture thereof, which is a raw material usually used in the manufacture of cement.

As the calcium stimulant, it is preferable to use at least one selected from calcium sulfate, calcium nitrate, calcium silicate, calcium hydroxide, calcium chloride, calcium stearate, calcium metaphosphate, calcium lactate and calcium oxide. Calcium-based irritants show a more stable response than strong alkaline irritants.

As the calcium-based stimulant, CFBC ash containing calcium sulfate and calcium oxide is more preferably used. The calcium sulfate of the CFBC ash reacts with aluminum oxide (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ) components in the blast furnace slag to produce an aqueous image of ettringite, and calcium oxide is contacted with the compound water The reaction of CaO + H ₂ O -> Ca (OH) ₂ produces calcium hydroxide which acts as a stimulant for blast furnace slag. The generated calcium hydroxide reacts with the blast furnace slag to form a dense water image (light image) of the CSH water image (CaO-SiO ₂ -H ₂ O) system to impart strength to the blast furnace slag-based cement. Calcium hydroxide is a weakly alkaline irritant which is very advantageous for the development of initial and long-term compressive strength and is very effective in controlling the initial fluidity of cement and the loss of fluidity over time as it reacts with water-chain slag very stably. The calcium oxide component of CFBC ash is produced at a high temperature and has activity, so that it exhibits a higher intensity of the activity than the quicklime component in the market.

Fly ash does not have self-hardness like blast furnace slag but hydrates and cures if there is irritant such as calcium hydroxide. Fly ash has a relatively low amorphous (glassy component) component compared to blast furnace slag, but it reacts very stably with calcium hydroxide stimulant and is advantageous for long-term strength development rather than initial strength development.

In the cement composition of the present invention, the cement-promoting admixture is preferably used in an amount of 0.01 to 50 parts by weight per 100 parts by weight of the raw material selected from blast furnace slag, fly ash and a mixture thereof.

3. Active mortar, active concrete and Causes  product

The present invention is directed to active mortars and active concrete comprising the above cementitious compositions, wherein activated mortars and active concrete can be prepared by methods customary in the art.

In addition, the present invention relates to a cement product manufactured using the cement composition. Typical cement products include a brick, a block, a tile, a sewer, a boundary stone, a concrete file, a prestressed concrete, a concrete panel, , Foamed concrete, and concrete structures. Such cement products can also be produced by a conventional method in the art.

[ Example ]

Hereinafter, the present invention will be described in more detail with reference to examples. The following examples illustrate the invention and are not intended to limit the scope of the invention.

<Material>

1. Materials

The blast furnace slag was a commercially available product of S Company, and the specific surface area was 4,700 cm 2 / g. The fly ash used was refinery generated from Boryeong Thermal Power Plant and its specific surface area was 3400㎠ / g. The CFBC ash used as a stimulant was pulverized with a vibration mill to have a specific surface area of 5000 cm &lt; 2 &gt; / g. The components of each raw material were measured using X-ray fluorescence spectroscopy (XRF), and the results are shown in Table 1 below. Each particle shape was observed using an electron microscope (SEM), and the results are shown in Figs. 1A to 1C. FIG. 1A is an electron micrograph showing blast furnace slag, FIG. 1B is fly ash, and FIG. 1C is CFBC ash.

Blast furnace slag Fly ash CFBC Ash SiO ₂ 29.60 58.42 10.60 Al ₂ O ₃ 12.70 21.29 4.08 CaO 50.0 3.78 49.40 Fe ₂ O ₃ 0.87 5.13 1.44 MgO 3.19 1.26 0.53 Na ₂ O 0.18 1.63 0.20 K ₂ O 0.47 1.58 0.39 SO ₃ 1.82 0.00 20.80 Ig. 1.17 4.50 12.56

TEA and glycerin were used as the triol compound, and both compounds were used in the form of a liquid having a solid content of 85%.

<Test Method>

(1) mixing

Each material was dry-mixed, and a predetermined amount of the mixture and a chemical admixture for concrete were added and mixed in a mortar mixer. The mixture was subjected to measurement of physical properties and molded article molding using the paste.

(2) Curing

The materials were mixed and allowed to stand at room temperature (20 ° C) for 2 hours and then cured at 60 ° C for 24 hours to measure strength and physical properties.

(3) Compressive strength measurement

A 5 × 5 × 5 cm cubic mold was used. After curing at 60 ° C., the mold was demolded and the compressive strength was measured using a compressive strength machine.

< Example  1 and 2>

CFBC ash was used as a calcium - based stimulant for cement - based cement - based cement. TEA and glycerin were used as accelerating admixtures. The strength of the cured product after curing was compared with Comparative Example 1 in which no promoting admixture was added, Example 1 in which 1% of TEA was added, and Example 2 in which 1% of glycerin was added. The results are shown in Table 2 below. &Lt; tb &gt; &lt; TABLE &gt;

Cement composition and strength result (Unit:%) division W / B
blast furnace
Milled slag CFBC Ash TEA glycerin
Compressive strength (Mpa) 1 day 28th Comparative Example 1
45
90

10
- - 21.9 23.9 Example 1 One - 30.5 34.7 Example 2 - One 35.5 46.6

As can be seen from the above Table 2, Example 1 using TEA based on 28 days after curing showed a compressive strength of 145% as compared with Comparative Example 1 which is the standard formulation, and Example 2 using glycerin had 194 %, Respectively. Further, both of Example 1 and Example 2 exhibited an initial strength improvement of 139% or more as compared with Comparative Example 1, which is the reference formulation under the conditions of accelerated curing for 1 day.

< Example  3 and 4>

CFBC ash was used as a calcium stimulant in cement based on blast furnace slag, TEA and glycerin were used as accelerating admixtures, and AD1, a water reducing agent, was used for strength improvement. AD1 is a high performance water reducing agent with a carboxylic acid content of 20% solids.

Comparative Example 2 in which the promoter-type admixture was not added, Comparative Example 2 in which only the water reducing agent AD1 was added, Example 3 in which water reducing agent AD1 and glycerin were added, and Example 4 in which water reducing agent AD1, glycerin and TEA were added, . The results are shown in Table 3 below.

Cement composition and strength result (Unit:%) division W / B
blast furnace
Milled slag CFBC Ash AD1 ^* glycerin TEA Compressive strength (Mpa) 1 day 28th Comparative Example 2
25
90

10 1.4 - - 44.5 58.7 Example 3 1.4 0.6 - 59.4 81.4 Example 4 1.4 0.3 0.3 58.3 78.3

As can be seen from the results of Table 3, Examples 3 and 4 exhibited a high strength of 131% or more at 1 day and 28 days compressive strength, respectively, as compared with Comparative Example 2, which is the standard compound.

< Experimental Example  1>

The cured samples of Comparative Examples 2 and 3 were analyzed by X-ray diffraction (XRD) and electron microscopy (SEM). The results are shown in FIGS. 2 and 3.

2, the main water image showed a CSH (CaO-SiO ₂ -H ₂ O) phase and an Etringite phase similar to the cement water image, and Example 3 shows a comparative example 2 It can be seen that the amount of ettringite and calcium hydroxide is reduced. This is probably due to the fact that the activity of the blast furnace slag was promoted by the triol group at the end of glycerol. Especially, the decrease of calcium hydroxide was attributed to the dehydration of blast furnace slag and the dehydration of calcium hydroxide on the CSH.

As can be seen from the electron micrograph of FIG. 3, in Example 3 in which glycerin was added at 0.6% compared with Comparative Example 2 in which glycerin was not added, small, fine CSH water images were well developed, This is interpreted as a cause of increased compressive strength.

< Example  5 to 10>

The strength development rate of crown - blasted slag and fly ash was tested by cement.

CFBC ash was used as a calcium - based stimulant for cement based on blast furnace slag and fly ash. TEA and glycerin were used as accelerating admixtures and AD1 was used as a water reducing agent. AD1 is a high performance water reducing agent with a carboxylic acid content of 20% solids. The results are shown in Table 4, and the compressive strength according to the content of the triol compound is shown in FIG.

Cement composition and strength result (Unit:%) division W / B blast furnace
Milled slag CFBC
ash Fly
ash AD1 glycerin TEA Compressive strength (Mpa) 1 day 7 days 28th Comparative Example 3


25





65





10





25





1.4


- - 43.2 47.9 56.2 Example 5 0.1 - 53.0 60.4 67.8 Example 6 0.3 - 56.6 63.4 70.5 Example 7 0.6 - 58.3 66.2 74.2 Example 8 0.9 - 70.2 74.5 86.6 Example 9 1.5 - 71.2 75.4 88.1 Example 10 0.3 0.3 57.4 64.2 73.7

The addition of glycerin and TEA to blast furnace slag and fly ash-based cementitious materials increased strength compared to Comparative Example 3, which was the standard blend, and 120 % Strength. The initial strength was more than 160% at the use rate of 0.9% or more (both birthday days), and the strength was more than 150% even at 28 days curing. This seems to be due to the fact that the compound containing the triol at the end had a sufficient effect as a curing accelerator in both blast furnace slag and fly ash.

Claims (14)

A cement-promoting admixture comprising a triol compound. The method according to claim 1,
Wherein the triol compound is triethanolamine, glycerin or a mixture thereof. The method according to claim 1,
Wherein the admixture further comprises at least one selected from amines, glycerol, and glycols. The method of claim 3,
Wherein the amines are at least one selected from the group consisting of diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, diisopropanolethanolamine and isopropanol diethanolamine. The method of claim 3,
Wherein the glycerin is at least one selected from the group consisting of diglycerin, triglycerin, polyglycerin, phosphoglycerin, diphosphoglycerin and triphosphoglycerin. 6. The method of claim 5,
Wherein the glycerin is obtained as a by-product of biodiesel. The method of claim 3,
Wherein the glycols are at least one selected from the group consisting of propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol. A cement composition based on blast furnace slag, fly ash or a mixture thereof, comprising a calcium-based stimulant and the accelerating admixture of any one of claims 1 to 7. 9. The method of claim 8,
Wherein the promoting admixture is used in an amount of 0.01 to 50 parts by weight per 100 parts by weight of blast furnace slag, fly ash or a mixture thereof. 9. The method of claim 8,
Wherein the calcium stimulant is at least one selected from calcium sulfate, calcium nitrate, calcium silicate, calcium hydroxide, calcium chloride, calcium stearate, calcium metaphosphate, calcium lactate and calcium oxide. An activated mortar comprising the cementitious composition of claim 8. An active concrete comprising the cementitious composition of claim 8. A cement product produced from the cement composition of claim 8. 14. The method of claim 13,
Wherein the cement product is one of a brick, a block, a tile, a sewer pipe, a boundary stone, a concrete file, a prestressed concrete, a concrete panel, a concrete pipe, a manhole, a foamed concrete and a concrete structure.

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