KR102637810B1 - lightweight foam concrete composition and method for menufacturing the same - Google Patents

Abstract

According to one aspect of the present invention, it relates to a composition for lightweight foamed concrete for producing lightweight foamed concrete, which includes a binder mixed with fine powder obtained by screening and grinding CA-based refining slag (or reduced slag) and gypsum; and mixing water mixed with the binder, wherein the mixing water contains water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener, and the water is 25% to 50% by weight of the binder, The polycarboxylic acid-based water reducing agent is contained in an amount of 0.2% to 2% by weight of the binder, the setting retardant is contained in an amount of 0.2% to 2.0% by weight of the binder, and the cellulose-based thickener is contained in an amount greater than 0% by weight compared to the binder. A composition for lightweight foam concrete is provided, characterized in that it contains 0.5%.

Description

Composition for lightweight foam concrete and method for manufacturing lightweight foam concrete using the same {lightweight foam concrete composition and method for menufacturing the same}

The present invention relates to a composition for lightweight foam concrete and a method for manufacturing lightweight foam concrete using the same.

ALC (Autoclaved Lightweight Concrete) is a lightweight foam concrete manufactured by mixing siliceous and calcareous raw materials with foaming agents and admixtures and water, and foaming them through high-temperature and high-pressure curing (180℃, 10 atmospheres). ALC is used as a block for non-load-bearing walls such as interfloor flooring, partition walls, and exterior materials for fire-resistant and earthquake-resistant design of buildings.

In addition, 70-80% of the volume of ALC is formed of air bubbles, so it is 1/4 the weight of existing concrete, has high constructability, sound insulation, and insulation properties. It is manufactured from inorganic materials and has fire resistance, so it is used as an insulation, sound insulation, and fireproof material. do.

Recently, due to changes in lifestyles that pursue longer lifespan and diversity of apartment complexes, there has been a change to pillar-type structures such as ramen-type structures and mass-plate structures, and the demand for ALC, which is easy to construct and use as a partition material for temporary walls, is increasing.

However, ALC uses a large amount of natural raw materials, uses expensive Al powder or aluminum paste as a foaming agent, and has problems such as energy consumption and carbon emissions during the high-temperature curing process.

When manufacturing ALC, about 340 kWh/m ³ of energy is consumed to create high temperature and high pressure curing conditions, which, when converted to CO ₂ generation, emits about 168.3 kgCO ₂ /m ³ of CO ₂ .

Although CLC (cellular lightweight concrete) blocks, which replaced ALC blocks, have already been developed and commercialized in developed countries such as Europe, the ALC blocks currently used as insulating walls were developed in Sweden and Germany, and royalties are being paid.

Therefore, domestic technology is needed for the development of new eco-friendly blocks that can reduce royalties for ALC blocks and replace non-eco-friendly ALC blocks, while reducing cooling and heating energy consumption and reducing the weight of buildings.

Accordingly, CLC research is being conducted by some researchers in Korea recently, but compared to ALC produced through accelerated curing at a rate of 2 cycles/day, CLC produced through room temperature and pressure curing still has limitations in product production for commercialization.

Registered Patent 10-1392433 (Announcement Date: May 7, 2014)

The present invention is intended to provide a composition for lightweight foam concrete that can ensure material economic efficiency and environmental friendliness, and a method for manufacturing lightweight foam concrete using the same.

The present invention is intended to provide a composition for lightweight foam concrete that can manufacture lightweight foam concrete blocks that can replace ALC by securing the low density and strength standards of existing ALC in a short period of time, and a method of manufacturing lightweight foam concrete using the same.

The problem of the present application is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

According to one aspect of the present invention, it relates to a composition for lightweight foamed concrete for producing lightweight foamed concrete, which includes a binder mixed with fine powder obtained by screening and grinding CA-based refining slag (or reduced slag) and gypsum; and mixing water mixed with the binder, wherein the mixing water is water; Polycarboxylic acid-based water reducing agent; Set retardant; and a cellulose-based thickener; wherein the water is 25% to 50% by weight of the binder, the polycarboxylic acid-based water reducing agent is 0.2% to 2% by weight of the binder, and the setting retardant is contained in the binder. 0.2% to 2.0% by weight, and the cellulose-based thickener is provided in an amount of more than 0% to 0.5% by weight of the binder.

The binder includes CA (Calcium Aluminate)-based refining slag fine powder containing a lower content of Fe than the standard content and having a particle size smaller than the selection standard; and at least one gypsum selected from dihydrate gypsum and hemihydrate gypsum; wherein the CA-based refining slag fine powder includes CA-based minerals that are 40% to 60% of the CA-based refining slag fine powder, and the CA-based refining slag fine powder includes The fineness may be 5,000 cm ² /g to 7,000 cm ² /g.

The setting retardant may be composed of one or more selected from tartaric acid, sodium citrate, gluconic acid, and citric anhydride.

A foaming agent within 1% to 5% of the weight of the separate water may be mixed with the binder and the mixing water in separate water different from the mixing water.

It may further include PVA fibers in an amount of 0.5% to 2% of the volume of the lightweight foam concrete.

According to another aspect of the present invention, preparing a foaming agent dilution by diluting a foaming agent; Preparing mixing water containing water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener; Producing a paste by mixing a binder mixed with fine powder obtained by screening and grinding CA-based refining slag and gypsum and the mixing water; Generating bubbles according to the starter foam using the foaming agent dilution; Mixing the expanded foam and the paste to produce a lightweight foam concrete slurry; Pouring the lightweight foam concrete slurry; And curing the poured lightweight foam concrete slurry at room temperature, wherein the mixing water includes water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener, and the water is 25% of the weight of the binder. to 50%, the polycarboxylic acid-based water reducing agent is 0.2% to 2% by weight of the binder, the setting retardant is 0.2% to 2.0% by weight of the binder, and the cellulose-based thickener is 0.2% to 2.0% by weight of the binder. A method of manufacturing lightweight foam concrete is provided, characterized in that the content is greater than 0% to 0.5%.

The binder contains Fe at a content lower than the standard content and includes at least one gypsum selected from CA (Calcium Aluminate)-based refining slag fine powder and dihydrate gypsum and hemihydrate gypsum that are smaller than the selection standard particle size, and the CA-based refining slag fine powder is the above-mentioned. The CA-based refining slag fine powder contains 40% to 60% of CA-based minerals, and the fineness of the CA-based refining slag fine powder may be 5,000 cm ² /g to 7,000 cm ² /g.

The foaming agent may be diluted within 1% to 5% of the weight of the separate water in water different from the mixing water.

The generated air bubbles may be 50% to 80% of the total volume of the entire lightweight cellular concrete slurry.

The composition for lightweight foam concrete according to an embodiment of the present invention and the method for manufacturing lightweight foam concrete using the same are materially economical and eco-friendly by applying pre-battery technology using ultra-fast hardening cement based on refined slag (or reduced slag). can be secured.

The composition for lightweight foam concrete according to an embodiment of the present invention and the method for manufacturing lightweight foam concrete using the same are achieved by applying pre-battery technology using an ultra-fast hardening cement based on refining slag (or reduced slag), thereby improving the existing ALC in a short time. By securing low density and strength standards, it is possible to provide lightweight foam concrete blocks that can replace ALC.

The effects of the present application are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

Figure 1 shows a method for manufacturing lightweight foam concrete according to an embodiment of the present invention.
Figure 2 shows an example of an invention sample.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the attached drawings are merely explained to more easily disclose the content of the present invention, and the scope of the present invention is not limited to the scope of the attached drawings. Those skilled in the art will easily understand this. You will find out.

Additionally, the terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

In this application, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

(1) Binder

The composition for lightweight foam concrete according to the present invention uses a low-carbon, ultra-fast hardening cement composition containing gypsum and fine powder obtained by screening and grinding CA-based refining slag (or reduced slag) as the main binder.

The binder contains a lower content of Fe than the standard content, CA (Calcium Aluminate)-based refining slag fine powder smaller than the selection standard particle size, and one or more gypsum selected from dihydrate gypsum and hemihydrate gypsum.

The CA-based refining slag fine powder contains CA-based minerals that account for 40% to 60% of the CA-based refining slag fine powder, and the fineness of the CA-based refining slag fine powder is 5,000 cm ² /g to 7,000 cm ² /g.

In other words, the refining slag fine powder among the binders is obtained by dry slow cooling CA-based refining slag (or reduced slag) through process separation, and magnetically selecting slag of 5 mm under size (size less than 5 mm) through particle size screening to determine the Fe content. It is a raw material selected by excluding high-value samples, and is a fine powder with a CA mineral content of 40% to 60% and a powder size of 5,000 cm ² /g to 7,000 cm ² /g.

If the CS minerals in the refining slag are less than 40%, the initial and long-term strength is low, and if it is more than 60%, it may be difficult to secure work time for construction due to rapid setting even if more than 2% of the setting retardant is added. .

Unlike the binder of the present invention, if the powder size is less than 5,000 cm ² /g, the hydration reaction rate may decrease. Also, unlike the present invention, if the powder fineness is greater than 7,000 cm ² /g, the number of mixing increases, which reduces fluidity and may increase grinding costs to produce with high powder fineness.

The main mineral of the binder is a CA-based mineral. CA-based minerals ultimately produce C3AH6 minerals when reacted with water, but when mixed with gypsum, needle-like ettringite is formed on the surface through reaction with the elution of SO ₃ ^2- ions. (ettringite) (3CaO·Al ₂ O ₃ ·3CaSO ₄ ·32H ₂ O) is generated, which causes continuous strength development and can also contribute to long-term strength development.

Because ettringite has a high bound water, its density is low and it occupies a large volume, so it is often used as an intumescent material. Therefore, volumetric stability can be secured by compensating for shrinkage that occurred when a fast-hardening cement composition using dry, slow-cooled refined slag was used alone. possible.

Gypsum has different manufacturing conditions depending on the type, and its solubility and contribution to cement are different, and there is a potential risk of expansion and destruction due to the formation of ettringite due to excessive mixing, so the appropriate type of gypsum and mixing ratio are important decisions. Become a son of man.

Binder Manufacturing Example 1. High-quality, low-carbon, ultra-fast hardening cement composition using hemihydrate gypsum.

Calcined gypsum (CaSO ₄ ·1/2H ₂ O) is made by artificially processing gypsum dihydrate (CaSO ₄ ·2H ₂ O) into a semi-water state by high temperature treatment or high pressure treatment in parallel. It is sold domestically at a high unit price due to additional processing.

Hemihydrate gypsum has a higher initial solubility than dihydrate gypsum, so it contributes to a rapid reaction during mixing and can greatly improve the initial strength. Even 3 hours after mixing, the cement composition of the present invention has a maximum of 40 MPa (7-day strength level of ordinary Portland cement, 3 It was confirmed that expression was possible up to (time intensity expression not possible).

In this Production Example 1, only CA-based refining slag (or reduced slag) was subjected to dry slow cooling through process separation, and slag under 5 mm in size was magnetically screened through particle size screening to exclude samples with high Fe content, 100 parts by weight of fine powder containing 40% to 60% or more of CA (Calcium aluminate)-based minerals as selected raw materials and having a fineness of 5,000 cm ² /g to 7,000 cm ² /g, and a fine powder of 2,500 cm ² /g to 6,500 A low-carbon, ultra-fast hardening cement composition containing 10 to 30 parts by weight of cm ² /g hemihydrate gypsum is provided.

If the fineness of hemihydrate gypsum is less than 2,500 cm ² /g, the reactivity is low, and if the fineness of hemihydrate gypsum is greater than 6,500 cm ² /g, the grinding cost may increase excessively.

Binder Manufacturing Example 2. Low-cost, low-carbon, ultra-fast cement composition using gypsum.

Gypsum is classified into natural gypsum that is dissolved in seawater in its natural state or exists inside the earth's crust, and chemical gypsum, which collectively refers to waste gypsum produced during the process due to industrial development.

Natural gypsum has a higher purity than chemical gypsum, but its utilization rate is low due to its high unit price. In addition, chemical gypsum is produced in various processes such as phosphate gypsum, hydrofluoric acid gypsum, and desulfurized gypsum, and its unit price is low, making it highly utilized in the manufacture of construction materials.

Dihydrate gypsum has lower initial solubility than hemihydrate gypsum, so the 3-hour strength (5-10 MPa) development rate is low. However, from the age of 3 days, it develops a strength greater than that of semihydrated gypsum, which has advantages in terms of unit cost for manufacturing ultra-fast setting cement compositions, and in terms of the filling environment in that 100% industrial by-products are used when using chemical gypsum.

In this Production Example 2, only CA-based refining slag (or reduced slag) was subjected to dry slow cooling through process separation, and slag of 5 mm under size was magnetically selected through particle size screening to exclude samples with high Fe content, 100 parts by weight of fine powder containing 40% to 60% of CA (Calcium aluminate) minerals as selected raw materials and having a fineness of 5,000 cm ² /g to 7,000 cm ² /g, fine powder of 2,500 cm ² /g to 6,500 cm Provided is a low-cost, low-carbon, ultra-fast hardening cement composition comprising 20 to 40 parts by weight of natural gypsum or chemical gypsum having ² /g.

Binder Preparation Example 3: Low-carbon super-hardening cement composition using a mixture of hemihydrate and dihydrate gypsum

When using hemihydrate gypsum, the strength development rate at initial age (1 hour, 3 hours, and 1 day strength) is high, but as the problem of increased unit cost arises, a composition using an appropriate mixture of hemihydrate and dihydrate gypsum can also be used depending on the purpose. .

In this Production Example 3, only CA-based refining slag (or reduced slag) was subjected to dry slow cooling through process separation, and slag of 5 mm under size was magnetically selected through particle size screening to exclude samples with high Fe content, Selected raw materials include 100 parts by weight of fine powder containing 40% to 60% of CA (Calcium aluminate) minerals and having a fineness of 5,000 cm ² /g to 7,000 cm ² /g, 10 to 30 parts by weight of hemihydrate gypsum, and natural Provided is a low-carbon, ultra-hard cement composition containing 20 to 40 parts by weight of dihydrate gypsum selected from dihydrate gypsum or chemical gypsum.

delete

When using the above binder, the amount of natural raw materials used in existing ALC can be greatly reduced, and because it has rapid hardening properties, it develops more than the 3-day strength of ordinary Portland cement even in the first 3 hours, enabling handling strength to be secured in a short period of time without accelerated curing. possible.

Therefore, the production cycle can be increased from 2 cycles of existing ALC to 4 cycles. In addition, since there is no accelerated curing, it is an eco-friendly process that can reduce curing energy and _CO2 emissions generated during curing.

(2) Mixing water

The mixing water to be mixed with the binder is a mixture of water, polycarboxylic acid-based water reducing agent, setting retardant, and cellulose-based thickener.

The water in the mixing water ranges from 25% to 50% of the weight of the binder.

To ensure fluidity, a polycarboxylic acid-based water reducing agent (solid content 20%) is mixed in an amount of 0.2% to 2% based on the weight of the binder.

To prevent rapid setting of the binder and secure working time, a setting retardant is used by dissolving in water 0.2% to 2.0% of the weight of the binder depending on the required working time. The setting retardant may be composed of one or more selected from tartaric acid, sodium citrate, gluconic acid, and citric anhydride.

Cellulose-based thickener is used in an amount greater than 0% and within 0.5% of the weight of the binder and is dissolved in mixing water.

At this time, the reasons for limiting the use and content of each material mixed in the mixing water are as follows.

If the mixing water is used at less than 25% of the weight of the binder, workability cannot be secured and high density is caused, and if the mixing water is more than 50% of the weight of the binder, it may be difficult to secure initial handling strength.

Polycarboxylic acid-based water reducing agent is added to secure the fluidity of the slurry mixed with binder and mixing water and reduce the unit quantity. If less than 0.2% is used, the additional quantity increases to ensure fluidity, ultimately reducing the strength of the final lightweight foam concrete. It causes an increase in manufacturing cost if used in excess of 2.0%.

The use of a setting retardant may affect the securing of working time by delaying the initial formation time of ettringite, the main mineral of C12A7, the main mineral of the refining slag-based low-carbon quick-hardening cement used as a binder. The setting retardant may affect the securing of working time compared to the weight of the binder. If used in less than 0.2%, it is impossible to secure working time for manufacturing lightweight foam concrete due to rapid setting within 5 minutes immediately after mixing the mixing water and binder, and if mixed in more than 2%, delayed setting and reduced strength occur. It also causes an increase in manufacturing costs.

The use of a thickener increases the viscosity of the slurry and prevents defoaming of the bubbles until the slurry hardens and the matrix stabilizes by mixing the pre-foamed bubbles separately. If the thickener is mixed in excess of 0.5% by weight of the binder, the fluidity of the slurry is drastically reduced, making it impossible to maintain sufficient workability and flatness for concrete production.

(3) Starting artillery

For starter foaming, a foaming agent is mixed and diluted in separate water from the mixing water within 1% to 5% of the weight of the separate water or 0.05% to 0.2% of the weight of the binder. The foaming agent may be made of one or more of AES (Alcohol Ethoxy Sulfate), AOS (Alpha Olefin Sulfonate), VS (Vegetable Soap), and FP (Fe-Protein).

If the foaming agent is less than 1% by weight of separate water or less than 0.05% by weight of binder, the stability of the bubbles is low and they may be defoamed and not form a stable volume.

In addition, if the foaming agent is greater than 5% by weight of separate water or greater than 0.2% by weight of the binder, stability is not proportional to the increase in foaming agent content, and not only reduces the stability of the foam, but also increases the unit cost of the foaming agent. Efficiency in some areas may also decrease.

(4) PVA fiber
Lightweight foam concrete has a relatively low compressive and flexural strength compared to regular concrete because it contains a large amount of voids within the matrix. Therefore, PVA (Polyvinyl Alcohol) fiber is used to improve handling strength and bending toughness to improve tensile strength and prevent cracks.

The total amount of PVA fibers used in the present invention is 0.5% to 2% of the volume of lightweight foamed concrete produced by the composition for lightweight foamed concrete of the present invention. If the total amount of PVA fibers is less than 0.5%, the handling strength and bending strength may not be sufficiently reinforced, and if the total amount of PVA fibers is more than 2.0%, the compressive strength may be significantly reduced even if the bending strength is improved. You can.

Example 1. Method for manufacturing lightweight foam concrete
Next, a method for producing lightweight foam concrete using the above composition will be described. The method for producing lightweight foam concrete according to an embodiment of the present invention uses a pre-foaming method. The existing ALC was post-foamed to form voids during the accelerated curing process of a slurry mixed with an Al-based foaming agent. In contrast, the pre-foaming method of the present invention adds pre-prepared bubbles to the concrete slurry, so the density of the cured body can be controlled by freely controlling the bubbles, and the constructability is good and spherical bubbles can be generated.

The method for manufacturing lightweight foamed concrete of the present invention includes the following steps: 1) diluting a foaming agent to prepare a foaming agent dilution, 2) preparing mixing water containing water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener, 3 ) Paste production step (hereinafter referred to as paste production step) by mixing a binder mixed with fine powder and gypsum mixed with CA-based refining slag and mixing water, 4) Creating bubbles according to the starter foam using a foaming agent diluent. Step (hereinafter referred to as preliminary foaming step), 5) Step of mixing the foamed bubbles and paste to produce a lightweight cellular concrete slurry (hereinafter referred to as lightweight cellular concrete slurry manufacturing step), 6) Step of pouring the lightweight cellular concrete slurry (hereinafter referred to as: , pouring step), and 7) a step of curing the poured lightweight foam concrete slurry at room temperature (hereinafter, room temperature curing step).

In the foaming agent dilution step, the foaming agent is diluted to within 1% to 5% by weight of water. Alternatively, 0.05% to 0.2% of a foaming agent is mixed based on the weight of the binder.

The mixing water manufacturing step is a step of preparing mixing water to be mixed with the binder. The mixing water includes water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener.

The water in the mixing water may be 25% to 50% of the weight of the binder, and the polycarboxylic acid-based water reducing agent (solids 20%) may be 0.2% to 2% of the weight of the binder.

The setting retardant is mixed in an amount of 0.2% to 2.0% by weight of the binder, and the cellulose-based thickener is mixed in an amount of more than 0% to within 0.5% by weight of the binder so that it is completely dissolved in water.

The paste production step is a step of mixing mixing water with refining slag-based low-carbon ultra-fast hardening cement. Mixing water and refining slag-based low-carbon ultra-fast hardening cement are sufficiently mixed for 1 to 3 minutes using a concrete mixer or hand mixer.

If the mixing time is less than 1 minute, sufficient mixing may not be achieved, and if it exceeds 3 minutes, the working time is excessively increased.

The pre-foaming step is a step of forming pre-foaming bubbles using the foaming agent dilution prepared in the foaming agent dilution step. The foam formation is accomplished by introducing the foaming agent dilution using an air extrusion method and then forming bubbles through a foamer. Afterwards, volumetric measurement of the formed bubbles is performed.

In this process, the amount (volume) of air bubbles used is 50% to 80% of the total volume of the entire lightweight foam concrete slurry. If the cell volume is set to 50% or more, the density of the final lightweight foam concrete can be controlled to less than 1.0 kg/L, and if it is set to 80% or more, the density of the final lightweight foam concrete can be controlled to less than 0.3 kg/L, which requires handling during initial demolding. It is difficult to secure strength. Additionally, the volume of air bubbles can be adjusted depending on the density of the target concrete required.

The lightweight foam concrete slurry production step is a step of diluting the paste and prepolymer cells from the previous step, and volumetric measurement is performed by adjusting the ratio of prepolymer cells and paste to the target density of 0.3kg/L to 1.0kg/L of lightweight foam concrete. do.

The generated air cells may be 50% to 80% of the total volume of the entire lightweight cellular concrete slurry, and the paste may be 20% to 50% of the total volume of the entire lightweight cellular concrete slurry.

If the density of lightweight foamed concrete is less than 0.3kg/L, the strength of lightweight foamed concrete may be excessively low, and if it exceeds 1.0kg/L, the weight of lightweight foamed concrete may be excessively large.

After measuring the volume, thoroughly mix the starter foam and paste with a mixer such as a ribbon mixer, mortar mixer, or hand mixer. In this process, PVA fibers are added in an amount of 0.5% to 2% of the volume of lightweight foam concrete to ensure sufficient dispersion.

The pouring step is the step of pouring the lightweight aerated concrete slurry mixed in the lightweight aerated concrete slurry production step into a mold and shaping it by pouring it into the mold to be formed.

In the room temperature curing stage, unlike ALC's accelerated curing, curing is possible at room temperature without a separate heat source. The slag-based low-carbon, ultra-fast hardening cement used as a binder hardens within the first hour, and as it generates heat, it generates its own hydration heat and also has an insulation effect in the workplace. Through the present invention, it is possible to secure handling and demolding strength of more than 1 MPa within 3 hours after pouring of concrete manufactured with a target density of 0.3 kg/L to 1.0 kg/L.

Lightweight foam concrete manufactured according to the manufacturing method according to an embodiment of the present invention is environmentally friendly by reducing the consumption of natural resources as it uses refining slag, a by-product of the steel industry, as the main binder, and shortens the manufacturing process and does not require curing energy. Additionally, CO ₂ emissions can be reduced in the process of manufacturing lightweight foam concrete according to the manufacturing method according to an embodiment of the present invention.

For this reason, the manufacturing method according to the embodiment of the present invention can reduce production costs by reducing raw material costs and curing energy, and can also contribute to increasing daily production by increasing the mold turnover rate by reducing demolding time.

A test example is described below.

Test example. binder

In order to confirm the characteristics of lightweight aerated concrete manufactured without accelerated curing using a low-carbon super-hardening cement based on refining slag according to the present invention, a test sample as shown in Figure 2 was prepared as follows through the composition ratio and manufacturing method described above. It was manufactured as shown in Table 1. (Invention samples 1, 2, and 3 represent binders 1, 2, and 3, respectively)

division foam rate Wave mixture ratio binder Superplasticizer
(PC system) Set retardant thickener PVA fiber Invention sample 1 80%
35% 100%
One%
One%
0.3%
0.5%
(volume part) Invention sample 2 70% 100% Invention sample 3 60% 100%

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In Table 1, the cell rate indicates the ratio of the volume occupied by the first foam cells within the total amount of [unhardened paste volume (binder + water) + prefoam cell volume]. The higher the cell rate (percentage of prefoam cell content), the harder it is to cure. The weight of lightweight foam concrete is low, making low-density concrete possible.

When the cell rate is different, the density changes, and this is directly related to the strength of the hardened lightweight foam concrete, so the range of cell rate to satisfy the target compressive strength while satisfying the density of 0.3 to 1.0 is 60% to 80%. It was set to .

If the void ratio is less than 60%, the density will be more than 1.0, resulting in high-density concrete. If the void ratio is more than 80%, the density of 0.3 may be satisfactory, but the target strength will be difficult to achieve due to the large amount of voids and low matrix content that develops strength. You can.

The following Table 2 shows the compressive strength by density and age of lightweight foam concrete samples manufactured with the composition shown in Table 1 compared with the ALC block of 'S' company, which is commercially sold in Korea. Lightweight foam concrete manufactured by room temperature curing according to the present invention can develop strength at an early age (1 to 3 days), and its strength is similar to that of ALC manufactured/sold through existing accelerated curing. (Invention samples 1, 2, and 3 represent binders 1, 2, and 3, respectively)

division
Absolute dry weight Compressive strength (N/mm2(MPa))
note Domestic commercial ALC 3 hours 1 day 3 days Invention sample 1 0.355 3 (0.3 items) 1.5 2.4 2.9 Insulation performance
Reinforced products Invention sample 2 0.386 3.5 (0.4 items) 1.8 2.9 3.5 Invention sample 3 0.53 3.7 (0.5 items) 2.6 4.0 4.6 KS F 2701
(ALC block)

As described above, the embodiments according to the present invention have been examined, and the fact that the present invention can be embodied in other specific forms in addition to the embodiments described above without departing from the spirit or scope thereof will be recognized by those skilled in the art. It is self-evident. Therefore, the above-described embodiments are to be regarded as illustrative and not restrictive, and thus the present invention is not limited to the above description but may be modified within the scope of the appended claims and their equivalents.

Claims (9)

In the composition for lightweight foam concrete for producing lightweight foam concrete,
A binder mixed with fine powder obtained by screening and grinding CA-based refining slag (or reduced slag) and gypsum; And mixing water mixed with the binder,
The fine powder contains a lower content of Fe than the standard content by dry-annealing CA-based refining slag through process separation and magnetically selecting slag less than 5 mm in size through particle size screening, and has a CA-based mineral content of 40 It is a fine powder having a powder degree of % to 60% of 5,000 cm ² /g to 7,000 cm ² /g,
The gypsum has a fineness of 2,500 cm ² /g to 6,500 cm ² /g and is at least one of hemihydrate gypsum and dihydrate gypsum,
The mixing water contains water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener,
The water is 25% to 50% by weight of the binder,
The polycarboxylic acid-based water reducing agent is 0.2% to 2% by weight of the binder,
The setting retardant is 0.2% to 2.0% by weight of the binder,
The cellulose-based thickener is greater than 0% to 0.5% by weight of the binder,
The foaming agent diluent, in which 1% to 5% of the foaming agent by weight relative to the weight of the separate water is diluted in separate water different from the mixing water, is mixed with the binder and mixing water,
The bubbles generated depending on the starter are 50% to 80% of the total volume of the slurry,
A composition for lightweight foam concrete, characterized in that it further comprises PVA fibers in an amount of 0.5% to 2% of the volume of the composition for lightweight foam concrete. delete In claim 1,
A composition for lightweight foam concrete, wherein the setting retardant consists of one or more selected from tartaric acid, sodium citrate, gluconic acid, and citric anhydride. delete delete Diluting the foaming agent to prepare a foaming agent dilution;
Preparing mixing water containing water, a polycarboxylic acid-based water reducing agent, a setting retardant, and a cellulose-based thickener;
Producing a paste by mixing a binder mixed with fine powder obtained by screening and grinding CA-based refining slag and gypsum and the mixing water;
Generating bubbles according to the starter foam using the foaming agent dilution;
Mixing the expanded foam and the paste to produce a lightweight foam concrete slurry;
pouring the lightweight foam concrete slurry; and
A method of manufacturing lightweight foam concrete comprising the step of curing the poured lightweight foam concrete slurry at room temperature,
The foaming agent dilution is obtained by diluting 1% to 5% of the foaming agent in water based on the weight of water,
The water contained in the mixing water is 25% to 50% of the weight of the binder,
The polycarboxylic acid-based water reducing agent is 0.2% to 2% by weight of the binder,
The setting retardant is 0.2% to 2.0% by weight of the binder,
The cellulose-based thickener is greater than 0% to 0.5% by weight of the binder,
The fine powder contains a lower content of Fe than the standard content by dry-annealing CA-based refining slag through process separation and magnetically selecting slag less than 5 mm in size through particle size screening, and has a CA-based mineral content of 40 It is a fine powder having a powder degree of % to 60% of 5,000 cm ² /g to 7,000 cm ² /g,
The gypsum has a fineness of 2,500 cm ² /g to 6,500 cm ² /g and is at least one of hemihydrate gypsum and dihydrate gypsum,
The bubbles generated according to the starter cell are 50% to 80% of the total volume of the slurry,
A method of producing lightweight foam concrete, characterized in that PVA fibers are added and dispersed in an amount of 0.5% to 2% of the slurry volume in the step of producing the slurry. In claim 6,
The setting retardant is a method of producing lightweight foam concrete, characterized in that it consists of one or more selected from tartaric acid, sodium citrate, gluconic acid, and citric anhydride. delete delete