RU2510330C2 - Method of production of cellular concrete with closed pores (versions), device for making foam medium and mould for forming article to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to construction, particularly to production of cellular concrete particles. Proposed method comprises separate preparation of mortar and water, making foam of surfactant and water, mixing said mortar with foam, foam making, moulding the mix in the mould and thermal processing of article. Mortar is made by mixing water and cement at the following ratio, in wt %: cement - 25.0-58.0, water - 43.0-29.0. Cement is added into vessel with water at constant mixing to obtain homogeneous mortar. At a time, foam-like medium is made by mixing anionic and/or nonionic surfactant in amount of 0.05-0.2% per 30.0-9.0% of water degassed by thermal treatment at 20-95°C. Mixing is conducted by rubber disc fitted on drive shaft at 1000-3000 rpm. Obtained foam-like medium is added to mortar and mixer by mixer composed by piston engaged with drive to reciprocate vertically to produce homogeneous mass. Said mass is poured into molds and solidified at 1-37°C. Now, semi-finished moulded article is withdrawn to be cured at ambient temperature to solid state.

EFFECT: higher precision of finished articles.

10 cl, 3 dwg

Description

The invention relates to the field of production of building materials, and in particular to variants of a method for the production of structural and heat-insulating cellular concrete with closed pores and to devices for mixing a cement mass, to obtain a foam-like medium, and to a mold for shaping foam concrete products. The invention can be used to obtain products from non-autoclaved aerated concrete, both in the factory and at the construction site.

The prior art method for the manufacture of foam concrete products, including the separate preparation of cement-sand mortar from cement, ground sand, lime and water and foam from an aqueous solution of a foaming agent with their subsequent mixing (Glukhovsky V.D. and others. Basics of finishing technology, heat and waterproofing materials. - Kiev: Vishcha school. 1986. p.186-188).

The disadvantage of this method is the low strength of the foam.

As the closest analogue, the invention according to patent RU 2067569, 10.10.79, cl. C04B 40/02, which describes a method for producing cellular concrete, which provides for the separate preparation of a solution of cement and water, the preparation of foam from surfactants and water, mixing the cement mortar and foam, molding the mixture in a mold, heat treatment of products.

The disadvantage of this method is the appearance of a significant precipitate of the foam concrete mixture after pouring into the mold, as well as a low rate of porosity, and, as a consequence, low strength of the products.

The objective of the invention is to develop a technology for manufacturing cellular concrete with closed (closed) pores, which provides increased thermal protection by reducing density, increasing the strength of the products obtained, reducing the cost of manufactured products and simplifying manufacturing technology (thermal conductivity is proportional to density, i.e., a decrease in density leads to a decrease thermal conductivity and increase heat and soundproofing properties).

To solve the problem and achieve the technical result according to the first embodiment, the method of manufacturing aerated concrete with closed (closed) pores is that the cement mass is made by mixing water and cement in an amount (wt.%): Cement 25.0-58.0 %, water - 43.0-29.0%, while cement is introduced into the container with water in portions and / or evenly with constant stirring until a homogeneous cement mass is obtained; at the same time, a foamy medium is formed by mixing in an anion-free container (anion leg) and / or non-ionic (non-ionic) surfactant in an amount of 0.05-0.2%, taken in 30.0-9.0% of water previously degassed by heat treatment at T = 20-95 ° C, while mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 1000-3000 rpm, the resulting foamy medium is introduced into the cement mass and mixed with a mixer made in the form of a piston connected with the drive with the possibility of return translational motion in rtikalnom direction until a homogeneous mass, which is poured into molds, followed by curing at ambient temperature equal to 1-37 ° C, thereafter semi-finished molded article is recovered and kept at ambient temperature until solid.

There are other possible embodiments of the method, according to which it is necessary that:

- at the stage of mixing the foamy medium and the cement mass, an additional 30% alkali solution in an amount of 2.0-3.6% of the total amount of substances used would be added;

- cement would be introduced into the water during the formation of the cement mass by means of a screw conveyor;

- a wooden crush would be used as a piston.

To solve the problem and achieve the technical result according to the second embodiment, the method of manufacturing aerated concrete with closed (closed) pores is that the cement mass is made by mixing water and cement in an amount (wt.%): Cement 25.0-58.0 %, water - 42.5-27.8%, while cement is batchwise and / or evenly introduced into the container with water with constant stirring until a homogeneous cement mass is obtained, a foamy medium is formed by mixing in an anionic (anionic) tank, which is clean from cement, and /and whether a non-ionic (non-ionic) surfactant in an amount of 0.05-0.20%, taken in 30.0-9.0% of water previously degassed by heat treatment at T = 20-95 ° C, while mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 1000-3000 rpm, a cellulose pulp containing 0.36-1.70% cellulose is made, the cement mass is introduced into it and mixed with a mixer made in the form reciprocating piston stirring in the vertical direction until a homogeneous mass is obtained, into which the previously obtained foamy medium is introduced and mixed by the same method, after which the obtained homogeneous mass is poured into molds, followed by hardening at a temperature of 1-37 ° C, after which a semi-finished molded product is removed and incubated at ambient temperature until solid.

There are other possible embodiments of the method, according to which it is necessary that:

- at the stage of mixing the foamy medium and the cement mass, an additional 30% alkali solution in an amount of 2.0-3.6% of the total amount of substances used would be added;

- cement would be introduced into the water during the formation of the cement mass by means of a screw conveyor.

- a wooden crush would be used as a piston.

Various methods and devices are known from the prior art for producing a foamy medium, according to which the foam is obtained by whipping a liquid mixture of rosin soap and animal glue, and blocks and slabs are made from the resulting foam concrete, which are autoclaved at 170 ° C and 8 kg / cm ² . To prepare aerated concrete for foam use aluminum powder / paste / or other gas-forming substances, which are introduced into the cement mass. During the interaction of aluminum powder with cement lime, gas (hydrogen) is released, which swells the cement mass. The consumption of aluminum powder per 1 m ^{3 of} aerated concrete does not exceed 15-20 kg. The properties of aerated concrete are similar to foam concrete, see the Handbook on Civil Engineering, Kiev, Budivelnik, 1965, pp. 162-165 / 1 / and the Handbook of the State Farm Builder, Because of Agricultural Literature, M., 1962, p. 130- 131/2 /. Known lightweight concrete based on expanded clay, perlite, etc., materials with a bulk weight of up to 1800 kg / m ³ / cm 1, p. 157-162 /.

A device for producing a foamy medium is also known - a foaming agent (RU, No. 2400452, C2, 09/27/2010), which contains resin and a surfactant. The resin used is rosin washed off with sodium hydroxide or potassium hydroxide. One or more substances selected from primary alkyl sulfates, alkyl ethoxysulfates, alkyldimethyl carboxy betaine, cocamidopropyl betaine, alkyldimethylamine oxides, alpha olefin sulfonates, secondary alkyl sulfates are used as a surfactant. The foaming agent further comprises an organic solvent. The organic solvent is selected from the group of lower primary alcohols or their hydroxyethylation or hydroxypropylation products. The minimum total content of rosin soap and surfactant in the composition of the foaming agent is 4.0 wt.%. The use of a foaming agent makes it possible to obtain foams that are stable in a cement test with a multiplicity of at least 15. Negative is the high cost and complexity.

As the closest analogue, the application RU 2001113568, 06/27/2003, cl. B28B 5/38, which describes a device for producing a foamy medium containing a container, a mixer mounted on a drive shaft, the mixer being made in the form of a rubber disk. Known devices have increased cost, complexity in the manufacture and operation.

The objective of the invention is the development of a device for producing a foamy medium with low cost, structural simplicity and ease of use.

To solve the problem and achieve a technical result, the device for producing a foamy medium is made in the form of a rubber disk 0.5-3.7 mm thick, mounted on the drive shaft and immersed in a container to a depth of 20-55% of the water level with a rotation speed equal to 1000-3000 rpm, while the area of the rubber disk is 30-70% of the maximum cross-sectional area of the tank with water.

It is advisable to perform a disk of reinforced rubber.

It is known from the prior art that for the manufacture of blocks of cellular concrete it is necessary to pour the resulting foam concrete into special forms. Existing installations currently have casting means for this - hoses or hoses, through which the porous concrete mass is poured into molds that can be made of metal or plastic. In this case, the forms are located in cassettes of several pieces. The collapsible cassette form is poured simultaneously into 30 blocks (1.15 m ³ ), the forms are stacked on top of each other, which saves production space. However, metal cassettes with molds for foam concrete are roads and metal consuming. Plastic molds for the production of cellular concrete blocks are much easier and cheaper, however, their service life is short (TechTron LLC website, www.textron.com, 2012).

As the closest analogue, patent RU 2065815, 08/27/1996, class. B28B 11/00, which describes a mold for shaping foam concrete products, is made in the form of solid removable walls located at least on the sides and the base, coated on the inside with a plastic film.

The objective of the invention is to develop a mold for forming a product from foam, having a low cost, structural simplicity and ease of use, preferably for small volumes of construction by simplifying the form stripping.

To solve the problem and achieve a technical result, the mold for shaping foam concrete products is made in the form of solid removable walls located at least on the sides and the base, covered on the inside with a plastic film, 40-30 microns thick, with side walls on adjacent sides and / or corners are connected by connecting elements with the possibility of forming the desired shape of the product.

In addition, it is advisable to perform connection elements in the form of rubber ties or ropes.

In addition, it is advisable to use the natural base of the earth or the floor of the building, covered with plastic film, as the wall from the bottom.

These signs are essential and interconnected causally with the formation of a set of essential signs sufficient to achieve a technical result, in particular, to reduce density, thermal conductivity, reduce costs and simplify manufacturing technology, as well as ensure ease of use by simplifying form stripping.

The invention is illustrated by drawings, where:

figure 1 - device for mixing a cement mass.

figure 2 - form for a foamy environment.

figure 3 - device for shaping.

The invention is illustrated by a specific example of implementation, which, however, is not the only possible, but clearly demonstrates the possibility of achieving this set of essential features of a given technical result.

According to the invention according to the first embodiment, a method of manufacturing aerated concrete with closed (closed) pores is to perform the following operations:

- produce a cement mass by mixing water and cement in an amount (mass%): cement - 25.0-58.0%, water - 43.0-29.0%, while in a container with water portionwise and / or evenly cement is introduced with constant stirring until a homogeneous cement mass is obtained,

- at the same time form a foamy medium by mixing in an anionic surfactant-free container in the form of sodium alkylbenzosulfate in an amount of 0.05-0.2%, taken in 30.0-9.0% of water previously degassed by heat treatment at T = 20-95 ° C, while mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 1000-3000 rpm,

- the resulting foamy medium is introduced into the cement mass and mixed with a mixer made in the form of a piston connected to the drive with the possibility of reciprocating movement in the vertical direction to obtain a homogeneous mass, which

- poured into molds followed by hardening at an ambient temperature of 1-37 ° C, after which

- remove the semi-finished molded product and

- maintained at ambient temperature to a solid state.

In order to increase the stability of the foam, at the stage of mixing the foamy medium and cement mass, an additional 30% solution of alkali, namely sodium silicate, is added in an amount of 2.0-3.6%.

To simplify the process of manufacturing the cement mass, cement is introduced into the water through a screw conveyor, and a wooden crusher is used as a piston.

According to the invention according to the second embodiment, the method of manufacturing aerated concrete with closed (closed) pores is that

- make a cement mass by mixing water and cement in an amount (mass%): cement - 25.0-58.0%, water - 42.5-27.8%, while in a container with water portionwise and / or evenly cement is introduced with constant stirring until a homogeneous cement mass is obtained,

- form a foamy medium by mixing in a tank of cement-free nionic surfactant, namely, ethoxylated alkyl phenol, in an amount of 0.5-2.0%, taken in 30-9.0% of water previously degassed by heat treatment at T = 20- 95 ° C, while mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 1000-3000 rpm,

- make cellulose pulp containing 0.36-1.7% cellulose;

- inject the cement mass into it and mix it with a mixer made in the form of a piston connected to the drive with the possibility of reciprocating movement in the vertical direction to obtain a homogeneous mass into which

- the previously obtained foamy medium is introduced and mixed by the same method, after which the resulting homogeneous mass is poured into molds, followed by hardening at a temperature of 1-37 ° C, after which the semi-finished product is molded and

- maintained at ambient temperature to a solid state.

In order to increase the stability of the foam at the stage of mixing the foamy medium and cement mass, an additional 30% alkali solution in the form of lime in an amount of 2.0-3.6% is additionally introduced.

To simplify the process of manufacturing the cement mass, cement is introduced into the water through a screw conveyor, and a wooden crusher is used as a piston.

For mixing the cement mass, a device made in the form of a flexible container 1 (Fig. 1) of an elastic material, for example rubber or a polymer material having a closure 2 into which water and cement are placed, can be used, the container is sealed, followed by a mechanical change, for example, by pressure with feet or hands, the shape of the container and providing, thereby mixing the components to obtain a homogeneous cement mass. For example, on the floor there is a bag of polymer material filled with water and cement, the worker walks along it with his feet in various directions - along, across, diagonally, back and forth until a homogeneous cement mass is formed.

According to the invention, a device for producing a foamy medium is made in the form of a rubber disk 3 (Fig. 2) with a thickness of 0.5-3.7 mm, mounted on a drive shaft 4 and immersed in a container 5 to a depth of 20-55% of water level 6 at a speed rotation equal to 1000-3000 rpm

The area of the rubber disk 3 is 30-70% of the maximum. In the process of manufacturing foam blocks of the cross-sectional area of the container with water, the size of the disk area is determined empirically, as well as the thickness of the rubber. In order to increase reliability, it is advisable to perform a disk 3 of reinforced rubber.

In the process of manufacturing products from foam concrete according to the invention, mold 7 (FIG. 3) is used to form the product, made in the form of solid, for example, plywood, plastic, metal walls 8 located on the sides and base 9. On the inside of the wall 8 and the base 9 is covered with a thin plastic film 10, a thickness of 40-30 microns.

The side walls 8 on adjacent sides and / or corners are interconnected by the elements of the connection 11 with the possibility of forming the desired shape of the product, for example a rectangular box, a cube, a triangular prism, an arched shape, etc. The use of flexible material for the side walls 8 allows you to make curly products by deforming the surface of the walls.

In order to simplify the design of the form and reduce its cost, it is advisable to perform connection elements in the form of rubber ties or ropes.

To solve the same problem, it is advisable as the base wall, i.e. from the bottom, use a flat area of land, road surface or floor of the room, covered with a thin plastic film 10.

This embodiment has structural simplicity and ease of use due to the simplification of formwork.

According to the first embodiment, the implementation of the method for manufacturing closed-cell cellular concrete can be presented in the following example.

As starting materials for option No. 1 is used in wt.%:

Composition for option No. 1 Mach for "easy" foam Min "heavy" foam water - part number 1 43 29.2 30,0 Anionic surfactant - sodium alkyl benzosulfate 0.05 0.2 0.1 Water part number 2 29.95 9 17.4 cement 25 58 fifty 30% aqueous solution of sodium silicate 2.0 3.6 2,5

As starting materials for option No. 2 used in wt.%:

Composition for option No. 2 Max for light foam Min "heavy" foam water - part number 1 42.5 27.8 30,0 nonionic surfactant - ethoxylated alkyl phenol, 0.05 0.2 0.1 Water part number 2 thirty 9 17.0 cement 25 58 49 30% aqueous solution of lime 2.0 3.6 2.9 cellulose 0.36 1.7 1,0

After forming the composition according to the claimed technology, the following operations are carried out for the manufacture of foam concrete and products from it:

firstly, they mix water in an amount of 43% and cement in an amount of 25%, while cement is added portionwise to the container with water with constant stirring until a homogeneous cement mass is obtained;

secondly, in parallel with this process, a foamy medium is formed by mixing in a tank clean of cement, anionic surfactant-sodium alkylbenzene sulfate, in the amount of 0.05%, taken in 30% of water previously degassed by heat treatment at T = 90 ° C, mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 3000 rpm;

thirdly, the resulting foamy medium is introduced into the cement mass and mixed with a mixer made in the form of a piston connected to the drive with the possibility of reciprocating movement in the vertical direction to obtain a homogeneous mass;

fourthly, the resulting mass is poured into molds, followed by hardening at an ambient temperature of 20 ° C and incubated for a day;

fifthly, remove the semi-finished molded product and incubated at ambient temperature until solid.

A feature of the second embodiment of the method is that simultaneously with the manufacture of the foamy medium, a cellulose pulp is produced containing 0.36-1.7% cellulose, into which the cement mass is portioned with constant stirring with a mixer, similar to the formation of a cement mass. Filling the cement mass with cellulose pulp relieves internal stresses, eliminates cracking and reduces the fragility of the product by applying the principle of reinforcing the product throughout the volume and in all directions.

The use of the invention allows to significantly increase the heat and sound insulation properties of the obtained product by varying the amount of cement and the quality of water used to obtain the cement mass while ensuring a working compressive strength of about 10-80 kg / cm ² at a density of 0.2-0.4 g / cm ³ due to the optimal combination of the quantitative ratio of cement / foam / water, which in turn significantly affects the cost per unit of output. In particular, the cost per square meter of living space made from a product obtained using patented technology is 1-3 thousand rubles / m ² , while structures from known foam blocks cost about 6-8 thousand rubles / m ² .

In addition, patented technical solutions make it possible to simplify the technology of manufacturing products from foam concrete, increase the ease of use, which will certainly find wide application in individual construction, in small production with small volumes of manufactured products. In essence, patented methods are universal with wide technical capabilities for a variety of building forms of manufactured products from foam concrete, which have enhanced strength, sound and heat insulation properties, as well as a service life.

Claims (9)

1. A method of manufacturing aerated concrete with closed (closed) pores (option 1), which provides for the separate preparation of a solution of cement and water, the preparation of foam from surfactants and water, mixing the cement mortar and foam, molding the foam, molding the mixture in the mold, heat treatment of products, characterized the fact that the cement mass is made by mixing water and cement in an amount, wt.%: cement 25.0-58.0, water 43.0-29.0, while cement is introduced in portions and / or uniformly at stirring constantly bottom of the cement mass, at the same time form a foamy medium by mixing in a container clean from cement anionic (anionic) and / or nonionic (nonionic) surfactant in an amount of 0.05-0.2%, taken at 30.0-9.0 % of water preliminarily degassed by heat treatment at 20-95 ° C, while mixing is carried out mechanically using a rubber disk mounted on the drive shaft with a rotation speed of 1000-3000 rpm, the resulting foamy medium is introduced into the cement mass and mix a mixer made in the form of a piston connected to the drive with the possibility of reciprocating in the vertical direction to obtain a homogeneous mass, which is poured into molds with subsequent hardening at an ambient temperature of 1-37 ° C, after which the semi-finished molded product is removed and incubated at ambient temperature until solid. 2. A method of manufacturing aerated concrete with closed (closed) pores (option 2), which provides for the separate preparation of a solution of cement and water, the preparation of foam from surfactants and water, mixing the cement mortar and foam, molding the mixture in a mold, heat treatment of products, characterized in that cement mass is produced by mixing water and cement in an amount, wt.%: cement 25.0-58.0, water 42.5-27.8, while cement is introduced into the container with water in portions and / or evenly with constant stirring up to obtaining a homogeneous cement m Assy, form a foamy medium by mixing in a tank of cement-free anionic (anionic) and / or nonionic (nonionic) surfactant in an amount of 0.05-0.20%, taken in 30.0-9.0% of water, previously subjected to degassing by heat treatment at 20-95 ° C, while mixing is carried out mechanically using a rubber disk mounted on a drive shaft with a rotation speed of 1000-3000 rpm, a cellulose pulp containing 0.36-1.70 % cellulose, injected into it cement mass and pulp they are sewn with a mixer made in the form of a piston connected to the drive with the possibility of reciprocating in the vertical direction to obtain a homogeneous mass into which the previously obtained foamy medium is introduced and mixed by the same method, after which the resulting homogeneous mass is poured into molds with subsequent hardening at a temperature of 1-37 ° C, then the semi-finished molded product is removed and kept at ambient temperature until solid. 3. The method according to claim 1 or 2, characterized in that at the stage of mixing the foamy medium and the cement mass, an additional 30% alkali solution is added in an amount of 2.0-3.6% of the total amount of substances used. 4. The method according to claim 1 or 2, characterized in that the cement is introduced into the water during the formation of the cement mass by means of a screw conveyor. 5. The method according to claim 1 or 2, characterized in that a wooden crush is used as the piston. 6. A device for producing a foamy medium for the manufacture of aerated concrete by the method according to claim 1 or 2, containing a container, a mixer mounted on the drive shaft, and the mixer is made in the form of a rubber disk with a thickness of 0.5-3.7 mm, mounted on the drive the shaft and immersed in the tank to a depth of 20-55% of the water level, with the possibility of rotation at a speed of 1000-3000 rpm, while the area of the rubber disk is 30-70% of the maximum cross-sectional area of the tank with water. 7. The device according to claim 6, characterized in that the disk is made of reinforced rubber. 8. A mold for shaping cellular concrete products made by the method according to claim 1 or 2, made in the form of solid walls located at least on the sides and the base, coated on the inside with a plastic film, while the side walls are adjacent the corners are interconnected with the possibility of forming the desired shape by the connection elements, characterized in that the polyethylene film is made with a thickness of 40-30 microns, and the connection elements are made in the form of rubber ties or rope. 9. The mold for forming according to claim 8, characterized in that the natural base of the ground or floor of the building, covered with a plastic film, serves as the wall from the bottom.

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