JP2017537053A - Cement-free admixture and cement-free composition containing the same - Google Patents

Abstract

The present invention relates to a cementless accelerating admixture containing a triol-based compound and a cementless composition containing the same, and the triol-based compound that is an accelerating admixture acts to promote hardening and consumes calcium hydroxide in the cured body. The C—S—H phase, which is an important hydration phase for strength development, is generated, and the C—S—H phase is small and densely developed to form a hydration phase advantageous for strength development. , Increase the strength of cementless hardened body. [Selection] Figure 3b

Description

  The present invention relates to a cement-free accelerated admixture, and more particularly to an accelerated admixture used in the production of cementless using a calcium-based stimulant and a cementless composition containing the same.

Carbon dioxide (CO ₂ ) is one of the typical causes of global warming as a kind of greenhouse gas. In South Korea, 80% of carbon dioxide is emitted from the energy industry, 24% of which is emitted from buildings, and the most common sources of carbon dioxide in building materials are rebar and cement. Therefore, various researches are underway to develop environmentally friendly building materials, particularly environmentally friendly concrete, that can reduce carbon dioxide emissions as much as possible while saving energy.

Concrete is made by putting aggregates such as sand, gravel and rebar into cement powder, mixed with water, and then put into a mold of a desired shape and hardened 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. Carbon dioxide generated in this process is produced while humans are engaged in industrial activities. It accounts for about 5% of the carbon dioxide produced and emitted, and has been pointed out as a serious problem.

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

  In the field of civil engineering, fly ash and granulated blast furnace slag are widely used as cement binders, and various researches have progressed as cementless raw materials. .

In research to use fly ash or granulated blast furnace slag as a cement-free raw material, potassium hydroxide (KOH), sodium hydroxide (NaOH), etc. are used to produce a cement-free hydrated phase or hardened body. Strongly alkaline stimulants are mainly used. Such a strong alkalinity stimulator is one in which Na ⁺ ions and K ⁺ ions are directly involved in the hydration phase of the cured product to produce a cementless cured product. There is a problem in the properties, the cost of raw materials is high, and it is difficult to put into practical use. Further, when a strong alkaline stimulant is used, there is a disadvantage that it is impossible to use a water reducing agent (chemical admixture for concrete) or the like because the pH rapidly increases and the reaction occurs rapidly.

In order to solve such a problem, fluidity is improved by using calcium-based stimulants such as calcium oxide, calcium hydroxide {Ca (OH) ₂ }, calcium sulfide (CaS) instead of strong alkaline stimulants. Research is progressing to secure a stable and more stable cured product. When a calcium-based stimulant is used, a stable reaction can be exhibited, fluidity can be secured, and time for maintaining fluidity can be secured. In addition, it is easy to use a water reducing agent and the strength can be increased by reducing water.

  Circulating fluidized bed ash (hereinafter referred to as “CFBC ash”) is an ash generated from a circulating fluidized bed combustion type boiler (CFBC boiler). Since the circulating fluidized bed combustion type boiler is a circulation type, the CFBC ash is at a very low temperature of 850 to 900 ° C. compared to 1200 to 1400 ° C. which is a production temperature of a general PC (Pulverized Combustion) boiler ash. Generated. At this temperature, the ash particles do not melt, so the surface area is reduced in the process of melting at high temperature and then cooling, and unlike the general PC boiler ash (refined ash) having a spherical shape, the surface shape of CFBC ash is indefinite. is there. Moreover, since it generate | occur | produces at the temperature lower than the temperature of a high temperature molten state, unlike refined ash, it does not contain the amorphous.

In a circulating fluidized bed combustion type boiler, the fluidized bed can be made limestone in order to increase the removal efficiency of sulfur dioxide (SO ₂ ) and nitrogen oxides (NO _x ) during combustion. When the fluidized bed is made of limestone, calcium oxide is generated from the limestone (CaCO ₃ ), which is the fluidized bed, by a decarboxylation reaction [CaCO ₃ = CaO + CO ₂ ↑], and trioxide generated from the circulating fluidized bed boiler in the furnace desulfurization method. Sulfur (SO ₃ ) and the calcium oxide are combined inside the boiler to produce calcium sulfate (CaSO ₄ ). Therefore, the main components of many CFBC ash are calcium oxide and calcium sulfate.

Korean Patent Publication No. 10-2005-0041439 Korean Patent Publication No. 10-2010-0040143 Korean Patent Publication No. 10-2010-0126736 Korean Patent Registration No. 10-1317647

  When using calcium-based stimulants when manufacturing cementless, the purpose is to increase the strength of the cementless hardened body by using a substance having a triol group as an accelerating component in the admixture used for water reduction. .

  In order to achieve the above-described object, the present invention provides a cementless accelerated admixture containing a triol-based compound.

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

  It is preferable that the admixture further includes one or more selected from amines, glycerols and glycols.

  The amine is preferably at least one selected from diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, diisopropanolethanolamine and isopropanoldiethanolamine.

  The glycerol is preferably one or more selected from diglycerol, triglycerol, polyglycerol, phosphoglycerol, diphosphoglycerol and triphosphoglycerol.

  The glycerin is preferably obtained as a biodiesel byproduct.

The glycols are preferably one or more selected from propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol and polyethylene glycol.

  Furthermore, the present invention provides a cementless composition based on granulated blast furnace slag, fly ash, or a mixture thereof, and containing a calcium-based stimulant and the above-mentioned accelerated admixture.

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

  In the composition, the calcium-based stimulant is one or more selected from calcium sulfate, calcium nitrate, calcium silicate, calcium hydroxide, calcium chloride, calcium stearate, calcium metaphosphate, calcium lactate and calcium oxide. It is preferable that

  Furthermore, this invention provides the active mortar and active concrete containing the said cementless composition.

  Furthermore, the present invention provides a cementless product produced with the cementless composition.

The cementless product is preferably a brick or a block.

  The cementless accelerated admixture of the present invention is produced by using blast furnace granulated slag, fly ash, or a mixture thereof as a raw material, and is used when producing a cementless hardened body using a calcium-based stimulant. The strength of the hardened cement can be increased by 20 to 60%. This is because when the cement-free product is produced using a calcium-based stimulant, the added triol-based compound acts to accelerate hardening, and the calcium hydroxide is consumed, which is an important hydration phase for strength development. This is probably because the —SH phase is generated and the C—S—H phase is small and densely developed to form a hydrated phase advantageous for strength development.

  Furthermore, when producing cementless concrete, the amount of powder can be reduced with the same strength, and the cost can be reduced.

FIGS. 1a to 1c are electron micrographs showing the grain shape of each raw material used, and FIG. 1a shows granulated blast furnace slag. 1a to 1c are electron micrographs showing the grain shape of each raw material used, and FIG. 1b shows fly ash. FIGS. 1a to 1c are electron micrographs showing the grain shape of each raw material used, and FIG. 1c shows CFBC ash. It is a graph which shows the result of the X-ray diffraction analysis of the cementless which added glycerol. 3a and 3b are cementless electron micrographs with glycerin added, and FIG. 3a is an electron micrograph of Comparative Example 2. 3a and 3b are cementless electron micrographs with glycerin added, and FIG. 3b is an electron micrograph of Example 3. FIG. It is a graph which shows the compressive strength by the content of a triol compound.

The present invention will be described in detail below.

1. Cementless accelerating admixture The cementless accelerating admixture of the present invention contains a triol-based compound and produces cementless using a calcium-based stimulant based on blast furnace granulated slag or fly ash. Use when.

  The triol group compound is a compound having a triol group at the end, and is a typical organic compound having a triol group at the end, such as triethanolamine (TEA), glycerin, or a mixture thereof. However, the present invention is not limited to this. It is more preferable to use both of these compounds in a liquid form having a solid content of 85%. The triol-based compound has a hardening-promoting action and enhances strength when producing cementless using a calcium-based stimulant.

  The accelerated admixture may further include one or more selected from amines, glycerols and glycols.

  * As amines, at least one selected from diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine (TIPA), diisopropanolethanolamine (EDIPA) and isopropanoldiethanolamine (DEIPA) is used. It is preferable to use it.

  As the glycerins, it is preferable to use one or more selected from diglycerin, triglycerin, polyglycerin, phosphoglycerin, diphosphoglycerin and triphosphoglycerin. It is particularly preferable to use glycerin obtained as a biodiesel byproduct.

  As glycols, it is preferable to use one or more selected from propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol.

2. Cementless composition The cementless composition of the present invention is based on blast furnace granulated slag, fly ash, or a mixture thereof, and includes a calcium-based stimulant and the above-mentioned accelerated admixture.

  As a raw material for producing cementless, it is preferable to use blast furnace granulated slag, fly ash, or a mixture thereof, which is a raw material usually used for producing cementless.

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

As the calcium-based stimulant, it is more preferable to use CFBC ash containing both calcium sulfate and calcium oxide. CFBC ash calcium sulfate reacts with aluminum oxide (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ) components in blast furnace granulated slag to produce a hydrated phase of ettringite, Calcium hydroxide that acts as a stimulant for granulated blast furnace slag is generated by the reaction of CaO + H ₂ O-> Ca (OH) ₂ when in contact with the blended water. The generated calcium hydroxide reacts with blast furnace granulated slag to form a dense hydrated phase (cured phase) of C—S—H hydrated phase (CaO—SiO ₂ —H ₂ O) system. Strength is given to the cement-free granulated slag base. Calcium hydroxide is a weakly alkaline stimulant that is very advantageous for the development of initial and long-term compressive strength, and has a very stable reaction with granulated slag. It is very effective for loss control. The calcium oxide component of CFBC ash is produced at a high temperature and has an activity, thereby exhibiting a higher strength than a commercially available quicklime component.

  Fly ash is not self-hardening like blast furnace granulated slag, but hydrates and hardens in the presence of stimulants such as calcium hydroxide. Fly ash has relatively few amorphous (glassy components) components compared to granulated blast furnace slag, but it has a very stable reaction with calcium hydroxide stimulants and develops longer-term strength than initial strength. Is advantageous.

  In the cementless composition of the present invention, the cementless accelerated admixture is used in an amount of 0.01 to 50 parts by weight per 100 parts by weight of raw materials selected from blast furnace granulated slag, fly ash, and mixtures thereof. preferable.

3. TECHNICAL FIELD The present invention relates to an active mortar and an active concrete containing the cementless composition, and the active mortar and the active concrete can be produced by a usual method in the art.

  Furthermore, the present invention relates to a cementless product manufactured using the cementless composition, and representative cementless products include bricks, blocks, tiles, sewer pipes, boundary stones, concrete piles, prestressed concrete. , Concrete panels, concrete pipes, manholes, cellular concrete, concrete structures. Such a cementless product can also be produced by a conventional method in the art.

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

<Material>
1. Material * The granulated blast furnace slag uses a product of company S which is generally commercially available, and the specific surface area was 4,700 cm ² / g. The fly ash uses refined ash generated by the Korea Boryeong Thermal Power Plant, and the specific surface area was 3400 cm ² / g. The CFBC ash used as the stimulant was pulverized with a vibration mill so that the specific surface area would be 5000 cm ² / g. Components of each raw material were measured using XRF (X-ray Fluorescence Spectroscopy), and the results are shown in Table 1 below. In addition, 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 granulated slag, FIG. 1b is fly ash, and FIG. 1c is CFBC ash.

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

<Test method>
(1) Mixing After each material was dry-mixed, a predetermined blending water and a chemical admixture for concrete were added and mixed with a mortar mixer. Using the mixed paste, measurement of physical properties and molding of a molded body were performed.

(2) Curing After mixing the materials, the mixture was 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) Measurement of compressive strength A 5 × 5 × 5 cm ³ cubic mold was used. After curing at 60 ° C., the mold was removed from the mold, and the compressive strength was measured using a compressive strength device. .

<Examples 1 and 2>
* CFBC ash was used as a calcium-based stimulant in cementless based on granulated blast furnace slag, and TEA and glycerin were used as accelerated admixtures. The strength of the cured product after curing was compared with Comparative Example 1 in which no accelerating admixture was added, Example 1 in which 1% of TEA was added, and Example 2 in which 1% of glycerin was added. The results of comparing the blending ratio and compressive strength are shown in Table 2 below.

  As can be seen from Table 2, on the basis of 28 days after curing, Example 1 using TEA shows a compressive strength of 145% as compared with Comparative Example 1 which is a reference composition, and an experiment using glycerin. Example 2 showed a strength expression rate of 194%. Moreover, both Example 1 and Example 2 showed an initial strength improvement of 139% or more as compared with Comparative Example 1, which is the reference formulation, under the condition of daily accelerated curing.

<Examples 3 and 4>
CFBC ash was used as the calcium-based stimulant for the cementless base based on granulated blast furnace slag, TEA and glycerin were used as the accelerating admixture, and the water reducing agent AD1 was used to improve the strength. AD1 is a carboxylic acid-based high-performance water reducing agent for concrete, having a solid solution content of 20%.

  Curing for Comparative Example 2 in which only the water reducing agent AD1 was added without adding the accelerating admixture, Example 3 in which the water reducing agent AD1 and glycerin were added, and Example 4 in which the water reducing agent AD1, glycerin and TEA were added The strength of the subsequent cured bodies was compared. The results of comparing the blending ratio and compressive strength are shown in Table 3 below.

As can be seen from the results in Table 3, Examples 3 and 4 showed a high strength expression rate of 131% or more in terms of 1-day and 28-day compressive strength, as compared with Comparative Example 2 which is a reference formulation.

<Experimental example 1>
The hydration phase was analyzed using the X-ray diffraction analysis (XRD) and the electron microscope (SEM) for the cured one-day specimens of Comparative Example 2 and Example 3, and the results are shown in FIGS. .

In the XRD analysis result shown in FIG. 2, the main hydration phase shows a C—S—H (CaO—SiO ₂ —H ₂ O) phase and an ettringite phase similar to the cement hydration phase. It can be seen that the amounts of ettringite and calcium hydroxide were reduced as compared with Comparative Example 2 which was the reference composition. This is thought to be because the activity of the blast furnace granulated slag was promoted by the triol group at the glycerin end. In particular, the decrease in calcium hydroxide was attributed to the promotion of hydration of the blast furnace granulated slag by CS- It is determined that this is because calcium hydroxide has been exhausted in the H phase.

  As can be seen from the electron micrograph of FIG. 3, compared with Comparative Example 2 in which glycerin was not added, Example 3 to which 0.6% of glycerin was added had a small and fine C—S—H hydrated phase. It is well developed and it is interpreted that such a small and dense hydrated phase is responsible for the increased compressive strength.

<Examples 5 to 10>
The strength development rate by the content of triol compound was tested in cementless using blast furnace granulated slag and fly ash at the same time.

  CFBC ash was used as a calcium-based stimulant, TEA and glycerin were used as an accelerating admixture, and AD1 was used as a water reducing agent component, without cement based on granulated blast furnace slag and fly ash. AD1 is a carboxylic acid-based high-performance water reducing agent for concrete, having a solid solution content of 20%. The results of comparing the compounding ratio and the compressive strength are shown in Table 4 below, and the compressive strength depending on the content of the triol compound is shown in FIG.

  Even in the cementless hardened body based on granulated blast furnace slag and fly ash, when glycerin and TEA were added, the strength increased compared to Comparative Example 3 which was the standard composition, and from the 1st to the 28th of the curing day The strength was 120% or more as compared with Comparative Example 3, which was the reference composition. When the amount used was 0.9% or more, an initial strength of 160% or more (curing day for 1 day) was shown, and even when it was cured for 28 days, it showed a strength of 150% or more. This is presumably because the compound containing the terminal triol sufficiently acted as a hardening accelerator for all of the granulated blast furnace slag and fly ash.

Claims (14)

  Cement-free admixture containing a triol-based compound.   The cementless accelerated admixture according to claim 1, wherein the triol group compound is triethanolamine, glycerin or a mixture thereof.   The cement-free accelerated admixture according to claim 1, wherein the admixture further comprises one or more selected from amines, glycerins and glycols.   4. The amine according to claim 3, wherein the amine is one or more selected from diethanolamine, monoethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, diisopropanolethanolamine and isopropanoldiethanolamine. The cementless accelerated admixture as described.   The cementless acceleration type according to claim 3, wherein the glycerin is one or more selected from diglycerin, triglycerin, polyglycerin, phosphoglycerin, diphosphoglycerin and triphosphoglycerin. Admixture.   6. The cementless accelerated admixture according to claim 5, wherein the glycerin is obtained as a biodiesel byproduct.   The glycol is at least one selected from propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, monoethylene glycol, diethylene glycol, triethylene glycol, and polyethylene glycol. The cement-free accelerated admixture described in 1.   A cementless composition based on granulated blast furnace slag, fly ash, or a mixture thereof, comprising a calcium-based stimulant and the accelerated admixture according to any one of claims 1 to 7.   The cementless composition according to claim 8, wherein the accelerated admixture is used in an amount of 0.01 to 50 parts by weight per 100 parts by weight of blast furnace granulated slag, fly ash, or a mixture thereof.   The calcium-based stimulant is one or more selected from calcium sulfate, calcium nitrate, calcium silicate, calcium hydroxide, calcium chloride, calcium stearate, calcium metaphosphate, calcium lactate and calcium oxide. The cementless composition according to claim 8.   An active mortar comprising the cementless composition according to claim 8.   An active concrete comprising the cementless composition according to claim 8.   A cementless product produced with the cementless composition according to claim 8.   The cementless product is any one of brick, block, tile, sewer pipe, boundary stone, concrete pile, prestressed concrete, concrete panel, concrete pipe, manhole, cellular concrete, and concrete structure. The cementless product according to claim 13.