KR20190027994A - Manufacturing Method of Waterproof Foamed Concrete Block - Google Patents

Abstract

Disclosed is a manufacturing method of a foam concrete block, which satisfies quality (over level 0.5) presented by lightweight foam concrete-related KS standard [KS F 2701 lightweight foam concrete (ALC) block], minimizes energy consumption when manufacturing foam concrete, and improves waterproof performance. According to the manufacturing method of a foam concrete block, in which bubbles are formed inside concrete, comprises: a step of manufacturing a plurality of bond materials including 95-99 wt% of cement, which is a unit bond material, and 1-5 wt% of gypsum, which is an admixture; a step of producing a cement paste by mixing the bond materials, water, and 0.4-1 part by weight of admixture with respect to 100 parts by weight of the bond materials; a step of manufacturing foam concrete by foaming mixed solution including 2-5 wt% of a foaming agent to mix bubbles having 1,000-1,500% of a foaming rate with the cement paste; and a step of curing the same after placing the foam concrete in a block mold.

Description

{Manufacturing Method of Waterproof Foam Concrete Block}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a method of manufacturing a foamed concrete block, and more particularly, to a wet type manufacturing method of a waterproof foamed concrete block.

Aerated Concrete is a kind of lightweight concrete that is made of lightweight concrete by making a lot of air bubbles in concrete without using aggregate. It is hygroscopic and drying shrinkage is much bigger than ordinary concrete.

The Autoclaved Lightweight Concrete (ALC) cured by autoclaving is made by curing a cement paste by forming a bubble inside the concrete by mixing a large amount of air bubbles with the physical interfacial action of foaming agent and forming a large number of pores inside Lightweight concrete.

Generally, lightweight foamed concrete is slurried by mixing calcite, siliceous raw material, foam stabilizer and admixture with water and then slurry is applied in autoclave at high temperature and high pressure (180, 10 Kg / ㎠) And is formed by a process of forming a tobermorite crystal of a plate structure.

This lightweight foamed concrete shows excellent performance in lightweight, heat insulation, fire resistance and construction, which are general advantages of lightweight concrete.

However, existing lightweight foam concrete blocks are energy consuming industries that require high temperature and high pressure (temperature about 180 ℃, pressure 10kg / cm2) during production process, and the manufacturing process is somewhat complicated. Also, it is brittle and easily absorbed, and it is difficult to control the degree of foaming in a post bubble-type manner, so that homogeneity and quality control of the product are difficult. In addition, the inner open cell facilitates penetration of water, which causes maintenance and maintenance costs due to mold and quality deterioration. In addition, a separate waterproofing treatment is required for outdoor application.

Korean Patent No. 10-1083937 discloses a lightweight building agent and a method for producing the same. The present invention describes a method for producing a lightweight building material such as a lightweight block or a lightweight composite panel by using an animal or vegetable base foam, but since there is no description of a method for controlling the open cell interior, an additional waterproofing agent treatment is required It has disadvantages.

Korean Patent No. 10-0120101 discloses a manufacturing method of lightweight foamed concrete. The present invention discloses a manufacturing method for lowering the manufacturing cost of lightweight foamed concrete using waste materials and pulverized paper. However, since a high-temperature firing furnace is used, the amount of energy used during production is large, Separate waterproofing measures are required.

Korean Patent No. 10-0653311 discloses a composition for producing lightweight foamed concrete containing heavy oils and a method for producing ALC using the same. In the present invention, a lightweight foamed concrete is manufactured by using a heavy oil sludge to lower the manufacturing cost. However, since the autoclave is used at a high temperature and a high pressure, there is a disadvantage in that the energy is not used in production.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the conventional art described above, and it is an object of the present invention to provide a lightweight foamed concrete which satisfies the quality (more than 0.5 items) proposed by the KS standard [KS F 2701 lightweight foamed concrete block (ALC block) It is an object of the present invention to provide a method of manufacturing a foamed concrete block with minimized energy consumption and improved waterproofing performance when manufacturing foamed concrete.

As a means for solving the above-mentioned technical problems, the present invention provides a method for producing a foamed concrete block in which bubbles are formed in concrete, comprising 95 to 99% by weight of cement as a unit binder and 1 to 5% ≪ / RTI > Mixing the admixture with the admixture in an amount of 0.4 to 1 part by weight based on 100 parts by weight of the plurality of binders, water, and the plurality of binders to produce a cement paste; And 2 to 5% by weight of a foaming agent is foamed to produce foamed concrete by mixing foamed bubbles having a foaming ratio of 1,000 to 1,500% with the cement paste; And a step of curing the concrete after the foam concrete is placed in the block formwork.

And the unit binder is 400 to 600 kg per cubic meter of the foamed concrete.

Further, the admixture may further include fly ash, and the plurality of binders may have a gypsum content of 1 to 5 wt%, a fly ash content of 1 to 25 wt%, and a cement content of 70 to 98 wt% A waterproof foamed concrete block,

Also, the cement paste has a blending ratio (W / B) of 0.20 to 0.30 according to the following formula (1).

[Equation 1]

Compounding ratio (W / B) = water unit weight / solid content end unit weight

(Wherein, in the above formula (1), the water unit weight is the weight (kg) of water per m3 of the composition contained in the composition, and the solid end unit weight is the total weight of the multiple binders and the admixture per unit m3 contained in the cement paste composition (kg).

The present invention also provides a method for producing a waterproof foamed concrete block, which is characterized in that the foam is an animal foam.

Also, the curing step is performed at a temperature of 10 to 40 ° C and a humidity of 30 to 80%.

According to the present invention, it is possible to improve the waterproof performance by forming air bubbles so that the air bubbles are formed in the field by wet production, the air is greatly shortened, the production cost is reduced, As a result, the heat insulating performance and the moisture-proof performance are improved.

In addition, the present invention can reduce excessive energy consumed in manufacturing a lightweight foamed concrete at a high temperature and a high pressure by manufacturing the foamed concrete through the proper curing with appropriate temperature and humidity, and reduce the carbon dioxide emission by 30 to 50% It is effective.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as " including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

The inventors of the present invention have conducted studies to reduce energy consumption by producing cement based on curing, rather than autoclave curing performed at high temperature and high pressure in the production of lightweight foamed concrete. As a result, It is economical because it cuts the air greatly, reduces the production cost, and improves the waterproof performance by forming bubbles so that the proper foam ratio is maintained inside the foamed concrete. The insulation performance and the moisture proofing which reduce the carbon dioxide emission by 30 ~ 50% It is possible to provide a method of manufacturing a lightweight foamed concrete having improved performance, leading to the present invention.

Accordingly, the present invention provides a method for producing a foamed concrete block in which air bubbles are formed in concrete, comprising the steps of: preparing a plurality of binders comprising 95 to 99% by weight of cement as a unit binder and 1 to 5% by weight of gypsum as an admixture; Mixing an admixture with 0.4 to 1 part by weight of the plurality of binders, water and the plurality of binders to produce a cement paste; Preparing a foamed concrete by foaming a mixed aqueous solution containing 2 to 5% by weight of a foaming agent and mixing foamed bubbles having a foaming ratio of 1000 to 1500% with the cement paste; And a step of curing the foamed concrete after the foamed concrete is placed on the block formwork.

Also, the foamed concrete block manufactured by the present invention can satisfy the quality (see Table 1 below) proposed by the KS standard (KS F 2701 lightweight foamed concrete block (ALC block)).

division Need for Speed Compressive strength (MPa) Thermal resistance value (m ² K / W) 0.5 Width 0.45 or more and less than 0.55 2.9 or higher 0.005 3 d 0.6 Width 0.55 or more and less than 0.65 4.9 or higher 0.004 2 d 0.7 Width 0.65 or more and less than 0.75 6.9 or higher 0.003 6 d d : Thickness of panel (mm)

The step of preparing the plurality of binders is a step of mixing 95 to 99% by weight of cement and 1 to 5% by weight of gypsum.

The cement is a unit binder used as a main material of foamed concrete, and 400 to 600 kg per 1 m 3 of the foamed concrete finally produced can be used. If the weight is less than 400kg, the density of the foamed concrete is lowered and the strength is lowered. If the weight is over 600kg, the density may be increased and the weight may be exceeded. In order to meet KS F 2701 0.5 standard, it is preferable to use 450 ~ 500kg per cubic meter of foam concrete. If the weight is less than 450kg, the specific gravity of grab is less than 0.45 and it is not satisfied with the KS 0.5 item. If it exceeds 500kg, the grab weight exceeds 0.55, which is equivalent to 0.6 of KS standard. The binder may be Portland cement, blast furnace slag cement, fly ash cement, silica fume cement, bottom ash cement, or the like.

In the present invention, the admixture has a relatively large amount of the admixture used for increasing the performance of the cement or replacing the cement having a high price. Therefore, the volume of the admixture is related to the calculation of the mixing ratio of the concrete. To 5% by weight. If the content of the admixture is less than 1%, the effect of the admixture may be deteriorated. However, in addition to the gypsum, fly ash, blast furnace slag, and fine powder pozzolan may be used as the admixture.

In the present invention, the admixture may further include fly ash. In this case, the gypsum content may be 1 to 5 wt%, and the fly ash content may be 1 to 25 wt% by substituting the cement. If the content of the admixture including the fly ash is more than 30% by weight, the adhesive strength of the cement is lowered to the final product Failure may occur. Preferably, the gypsum content may be 2 to 4 wt.%, The fly ash content may be 10 to 20 wt.%, And the fly ash content may be more than 20 wt.% To satisfy the KS F 2701 0.5 standard. In the case of foamed concrete, vesicles are generated and the compressive strength may be lowered.

The step of preparing the cement paste is a step of mixing the plural binders in which the cement and the admixture are mixed in water at a specific blending ratio, and adding 0.4 to 1 part by weight of the admixture to the plural binders to be mixed.

The compounding ratio (W / B) may preferably be 0.20 to 0.30 (20 to 30%) by the following formula (1) in order to satisfy 2.9 MPa or more based on 4-week compressive strength.

[Equation 1]

Compounding ratio (W / B) = water unit weight / solid content end unit weight

(Wherein, in the formula (1), the water unit weight is the weight (kg) of water per m3 of the composition contained in the composition, and the solid end unit weight is the total of the plural binders and the admixture per unit m3 contained in the cement paste composition Weight (kg).)

If the mixing ratio (W / B) is less than 20%, the amount of the admixture is increased due to the low unit water quantity, and the condensation strength of the concrete is lowered due to the delay of condensation and vesicles. If it exceeds 30%, the compressive strength of the foamed concrete may be lowered due to the increase of the unit quantity.

The admixture may include an alumina component based on a polycarboxylic acid system, which is used so that the amount of the admixture used does not affect the calculation of the concrete volume. In the present invention, the incorporation rate of the admixture may be 0.4 to 1 part by weight based on the weight of the plurality of binders, and if it is less than 0.4 part by weight, vesicles may be generated during the mixing of the air bubbles. If the amount exceeds 1 part by weight, Leakage may occur due to the mold seams in the mold when cast.

The step of fabricating the foamed concrete is a step of mixing a bubble group having a specific expansion ratio generated through a bubble generator with a cement paste by using a pre-bubble method. In the present invention, a mixed aqueous solution containing 2 to 5% by weight of a foaming agent is foamed, and air bubbles having a foaming ratio of 1,000 to 1,500% are mixed with the cement paste to prepare foamed concrete.

The foaming agent may be an animal foaming agent which is excellent in strength of the foaming film and has elasticity and has a low foaming rate and can prevent shrinkage cracking during firing. The foaming agent may be prepared by preparing the mixed aqueous solution having a dilution ratio of 2 to 5% The foaming ratio is preferably 1,000 to 1,500% to improve the waterproof performance of the foamed concrete block by inducing the independent foam. If the foaming ratio is less than 1,000%, the water content ratio of the bubbles is large, so that the compounding ratio (W / B) is increased and the compressive strength may be lowered. When the foam ratio is more than 1,500% And vapors may occur due to contact with the mixing container or the like.

The present invention includes a step of curing the foamed concrete after casting the foamed concrete in a block form in order to reduce excessive energy consumed in manufacturing a lightweight foamed concrete at a high temperature and a high pressure.

The curing step may be cured at a temperature of 10 to 40 ° C and a humidity of 30 to 80%, preferably at a temperature of 15 to 25 ° C and a humidity of 50 to 70%. When curing at less than 10 ° C, the curing period can be prolonged due to insufficient heat for curing. If it exceeds 40 ° C, rapid curing may cause defects. Also, when curing at less than 30% humidity, the surface moisture may evaporate and surface defects may occur. If it exceeds 80%, the surface may flow down due to excessive moisture.

Hereinafter, the present invention will be described in detail with reference to examples.

Test Example

The concrete prepared according to the following Examples 1 to 18 and Comparative Examples 1 to 7 was subjected to a physical property test (flow, settling depth, compressive strength and specific gravity specific gravity) in accordance with KS F 2701, Respectively.

Examples 1 to 5 and Comparative Examples 1 to 3

In order to confirm the physical property changes depending on the compounding ratio (W / B) of the water (W) and the plural binder (B), a plurality of binders mixed with cement and an admixture (gypsum) A cement paste is prepared according to the mixing ratio (W / B) of water and Table 2 below. An aqueous solution containing 5% by weight of an animal foam agent is formed in a bubble group having a blowing ratio of 1,500% through a bubble generator and mixed with the cement paste to prepare a foamed concrete. The fabricated foamed concrete was poured into the molds according to each designation and cured in a temperature of 20 ℃ and humidity of 60% to complete the wet type waterproof foamed concrete block.

division W / B
(%) unit
Binding discretion
(kg / m ³ ) Air void ratio
(%) Multiple binders (wt%) Admixture
(Parts by weight) Flow
(mm) Depth of Depth
(mm) Compressive strength
(MPa) Need for Speed cement Anhydrous plaster 7 days 28th Example 1 30 500 63.5 97 3 0.13 192 2 2.99 3.78 0.60 Example 2 27.5 500 64.7 97 3 0.23 200 0 3.47 4.28 0.61 Example 3 25 500 65.8 97 3 0.38 202 2 3.56 4.29 0.55 Example 4 22.5 500 67.0 97 3 0.56 266 3 3.04 3.71 0.55 Example 5 20 500 68.1 97 3 0.88 263 5 3.21 3.78 0.55 Comparative Example 1 32.5 500 62.4 97 3 0.1 200 0 1.71 2.22 0.54 Comparative Example 2 17.5 500 69.3 97 3 1.37 259 4 1.74 2.26 0.53 Comparative Example 3 15 500 70.4 97 3 3 261 5 2.12 2.50 0.51

Referring to Table 2, it was found that the compounding ratio (W / B) should be within 20 to 30% (Examples 1 to 5) in order to satisfy the compressive strength of 2.9 MPa (28 days). 25 to 30% (Examples 1 to 3) is more preferable considering the volume reduction of concrete depending on the depth of sinking (mm). When the mixing ratio (W / B) exceeds 30% (Comparative Example 1), the compressive strength of the foamed concrete decreases due to an increase in the unit water quantity. When the mixing ratio (W / B) is less than 20% (Comparative Examples 2 and 3) A large amount of delay and vesicles were generated, and the compressive strength was lowered.

Examples 6 to 10

A foamed concrete block was prepared in the same manner as in Example 1, except that the content shown in Table 3 below was used to confirm the change in physical properties according to the amount of the unit binder (cement).

division W / B
(%) unit
Binding discretion
(kg / m ³ ) Air void ratio
(%) Binder ratio (% by weight) Admixture
(Parts by weight) Flow
(mm) Depth of Depth
(mm) Compressive strength (MPa) Need for Speed cement Anhydrous plaster 7 days 28th Example 6 25 400 71.1 97 3 0.4 235 3 2.01 2.51 0.43 Example 7 25 450 68.4 97 3 0.4 245 0 2.75 3.67 0.51 Example 8 25 500 65.8 97 3 0.4 248 2 3.07 3.84 0.54 Example 9 25 550 63.2 97 3 0.4 237 One 4.15 5.07 0.64 Example 10 25 600 60.6 97 3 0.4 240 0 4.90 5.64 0.70

As shown in Table 3, when the unit bonding amount is 450 to 500 kg / m 3, it satisfies the 0.5-piece standard of KS F 2701 [lightweight foamed concrete block (ALC block)]. When the unit bonded amount is 400kg / ㎥, the specific gravity of grains is 0.45 or less, which is unsatisfactory to the KS standard 0.5, and when it is over 500 kg / ㎥, the grab weight exceeds 0.55, which is equivalent to 0.6 of the KS standard.

Examples 11 to 13 and Comparative Examples 4 to 6

Foamed concrete blocks were prepared in the same manner as in Example 1, except that the content shown in Table 4 below was used to confirm the change in physical properties with respect to the expansion ratio.

division Foaming rate
(%) W / B
(%) unit
Binding discretion
(kg / m3) Air void ratio
(%) Binder ratio (% by weight) Admixture
(Parts by weight) Flow
(mm) Depth of Depth
(mm) Compressive strength
(MPa) A mustard
importance cement Anhydrous plaster 7 days 28th Example 11 1500 27.5 450 68.4 97 3 0.5 265 0 2.75 3.42 0.48 Example 12 1250 27.5 450 67.4 97 3 0.5 230 0 2.91 3.72 0.50 Example 13 1000 27.5 450 65.9 97 3 0.5 225 0 2.43 3.13 0.49 Comparative Example 4 2500 27.5 450 70.3 97 3 0.5 255 0 1.26 1.59 0.49 Comparative Example 5 2000 27.5 450 69.6 97 3 0.5 250 0 1.34 1.49 0.48 Comparative Example 6 800 27.5 450 64.1 97 3 0.5 245 One 2.25 2.71 0.50

As shown in Table 4, when the foaming ratio is less than 1,000% (Comparative Example 6), the water content ratio in the bubbles is large, resulting in an increase in the mixing ratio (W / B) (Comparative Examples 4 and 5), it was found that bubbles could be generated due to contact with the paste, mixing container,

Examples 14 to 18 and Comparative Example 7

The foamed concrete block was prepared in the same manner as in Example 1, except that the contents shown in Table 4 below were used to confirm physical properties of the admixture (anhydrous gypsum and fly-ash).

division W / B
(%) unit
Binding discretion
(kg / m ³ ) Air void ratio
(%) Binder ratio (% by weight) Admixture
(Parts by weight) Flow
(mm) Depth of Depth
(mm) Compressive strength
(MPa) Need for Speed cement Anhydrous plaster Fly-Ash 7 days 28th Example 14 25 500 65.8 97 3 0 0.32 242 0 2.98 3.27 0.52 Example 15 25 500 65.0 87 3 10 0.49 259 0 3.12 3.39 0.52 Example 16 25 500 64.5 82 3 15 0.68 266 2 2.44 3.43 0.54 Example 17 25 500 64.1 77 3 20 0.97 278 One 2.17 3.12 0.54 Example 18 25 500 63.7 72 3 25 1.00 288 3 1.48 2.07 0.53 Comparative Example 7 25 500 63.2 67 3 30 1.43 300 5.5 0.45 0.68 0.59

As shown in Table 5, when the fly ash was not included (Example 14), it showed high compressive strength. When the fly ash was further included, the replacement amount of cement was 10 to 20% Examples 15 to 17) Compared to KS F 2701 0.5 parts (28 days compressive strength: 2.9 MPa or more) and exceeding 20% (Example 18 and Comparative Example 7) Respectively. At this time, when the content of the admixture including the fly ash is more than 30 wt% (Comparative Example 7), the adhesive force of the cement may be reduced and the final product may be defective.

The preferred embodiments of the present invention have been described in detail above. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Therefore, the scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the meaning, range, and equivalence of the claims are included in the scope of the present invention. .

Claims (6)

A method for manufacturing a foamed concrete block in which bubbles are formed in concrete,
95 to 99% by weight of cement as a unit binder and 1 to 5% by weight of gypsum as an admixture;
Mixing the admixture with the admixture in an amount of 0.4 to 1 part by weight based on 100 parts by weight of the plurality of binders, water, and the plurality of binders to produce a cement paste;
And 2 to 5% by weight of a foaming agent is foamed to produce foamed concrete by mixing foamed bubbles having a foaming ratio of 1,000 to 1,500% with the cement paste; And
The method of claim 1, further comprising the step of curing the foamed concrete after the foamed concrete is cast on the block formwork. The method according to claim 1,
Wherein the unit binder is 400 to 600 kg per cubic meter of the foamed concrete. The method according to claim 1,
Wherein the admixture further comprises fly ash,
Wherein the plurality of binders have a gypsum content of 1 to 5 wt%, a fly ash content of 1 to 25 wt%, and a cement content of 70 to 98 wt%. The method according to claim 1,
Wherein the cement paste has a blending ratio (W / B) of 0.20 to 0.30 according to the following formula (1).
[Equation 1]
Compounding ratio (W / B) = water unit weight / solid content end unit weight
(Wherein, in the above formula (1), the water unit weight is the weight (kg) of water per m3 of the composition contained in the composition, and the solid end unit weight is the total weight of the multiple binders and the admixture per unit m3 contained in the cement paste composition (kg). The method according to claim 1,
Wherein the foaming agent is an animal foaming agent. The method according to claim 1,
Wherein the curing step is performed at a temperature of 10 to 40 DEG C and a relative humidity of 30 to 80%.