RU2529973C1 - Composition for producing structural materials - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: composition for producing structural materials, comprising mineral binder, filler, water and nanomaterials, characterised by that the mineral binder is cement M-500 and bentonite clays, the filler is aluminosilicate microspheres (Al₂O₃) with diameter of 5.0-500 mcm, and as nanomaterials, the composition further includes a microstructure of needle-like wollastonite filler MIVOLL-97, free of natural calcium metal silicate, and fractional microcalcite MICARB "STANDARD"-96 and a foaming agent PB-200, with the following ratio of components, wt %: bentonite clays 2.0-8.0, aluminosilicate microspheres with diameter of 5.0-500.0 mcm 3.0-25.0, MIVOLL-97 - 1.5-5.5, MICARB "STANDARD"-96 - 2.0-8.0, silicon nanostructures AEROSIL - 2.0-5.0, foaming agent PB-200 - 1.0-4.0, water - 3.0-15, cement M-500 - the balance.

EFFECT: obtaining a high-strength composition with improved processing properties structural materials, the present combination of ingredients of the composition is optimal and enhances positive working qualities thereof.

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Description

The invention relates to compositions based on binders, such as cement, and can be used in the building materials industry in the manufacture of concrete, plaster, finish coatings, etc.

State of the art

Known technology for forming lightweight wall blocks and cellular concrete (see RF patents No. 2064410, 2137600, publ. 1996, 1999).

A known composition for producing building material containing cement, sand, water and carbon nanomaterial - carbon black obtained by the electric arc method and containing 7.0% carbon nanotubes, in the following ratio, wt.%:

Cement 20-30 Filler 50-70 Carbon nanomaterial 1-2 Water Rest

(see RF patent No. 2345968, publ. 2009 - analogue).

A disadvantage of the known composition is its high cost, due to the high energy consumption and uneconomical method of producing soot.

A known composition based on a mineral binder, including a mineral binder selected from the group comprising cement, lime, gypsum, or mixtures thereof and water, additionally contains carbon clusters of a fulleroid type with 36 carbon atoms or more in the following ratio of components in the composition (wt. %): mineral binder - 33-77; carbon clusters of the fulleroid type - 0.0001-2.0; water is the rest. As carbon clusters of the fulleroid type, the composition may contain polydispersed carbon nanotubes, polyhedral multilayer carbon nanostructures with an interlayer distance of 0.34 - 0.36 nm and a particle size of 60-200 nm, or a mixture of polydispersed carbon nanotubes and C ₆₀ fullerene. The composition may further comprise processing aids taken in an amount of 100-250 parts by weight. per 100 parts by weight mineral binder. Polyhedral multilayer carbon nanostructures were isolated from the cathode dipasite crust obtained in an arc discharge flame in a helium atmosphere by sequential oxidation operations in the gas and liquid phases. (see RF patent No. 2233254, publ. 2004 - analogue).

The disadvantage of this composition is its high cost, as well as insufficient compressive strength of concrete.

The closest set of essential features to the claimed composition is a composition for the production of building materials based on a mineral binder, including Portland cement, sand, water and a carbon material, and as a carbon material contains an aqueous suspension of cavitation-activated carbon-containing material - KAUM, which includes multilayer carbon nanostructures with an interlayer distance of 0.34-0.36 nm and a particle size of 60-200 nm, polydisperse carbon tubular formations with times measures 100000Å-1,000,000Å, hydrogenated carbon fractal structures with dimensions 1,000Å-1,000,000Å and active loose carbon with the dimensions of defective graphite microcrystallites approximately equal to 10Å in the following ratio of components in the composition, wt.%:

Portland cement 25-50 Sand 30-60 KAUM aqueous suspension 0.024-0.64 Water Rest

(see RF patent No. 2447036, publ. 2012 - prototype).

The objective of the present invention is to obtain a high-strength composition of building materials while reducing its cost by reducing energy consumption in the production of silicon nanomaterials, increasing the environmental friendliness of the product with increased ease, low reactivity, free flowability of the composition, fire resistance, seismic resistance and low heat conductivity.

The technical result consists in obtaining a high-strength composition with high technological properties of building materials, namely: an environmentally friendly product with increased lightness, free flowability, fire resistance, seismic resistance, low reactivity and low thermal conductivity. This combination of ingredients of the composition is optimal and enhances its positive technological qualities.

This object is achieved in that the composition for producing building materials containing a mineral binder, fillers, water and nanomaterials additionally contains M-500 cement and bentonite clays as a mineral binder, aluminosilicate microspheres (Al ₂ O ₃ ) with a diameter of 5, 0-500.0 μm, contains MIVOLL-97 filler needle-like wollastonite filler, purified by natural calcium silicate, and MIKARB fractional microcalcite - STANDARD - 96, as microstructures, and cre as nanostructures . Nevye AEROSIL nanostructure, and combinations thereof and a foaming agent PB-2000 - 2010, with the following ratio of components, wt%:

Cement M-500 Rest Bentonite clay 2.0-8.0 Aluminosilicate microspheres with a diameter of 5.0-500.0 microns 3.0-25.0 MIWALL "97" 1,5-5,5 MIKARB - "STANDARD" "96" 2.0-8.0

Nanostructures - silicon, carbon and their combinations

Aerosil 2.0-5.0 Frother PB-2000-2010 1.0-4.0 Water 3.0-15.0

The invention is illustrated by drawings, where:

Figure 1. a photograph of aluminosilicate microspheres with a diameter of 5.0-500.0 microns is presented;

Figure 2. a photograph of the structure obtained using an electron microscope of the needle wollastanite filler MIVOLL "97" purified by natural calcium metal silicate, and graphics are presented;

Figure 3. a photograph of the structure of ground and micronized marble filler MIKARB - "STANDARD" - "96";

Figure 4. - A graph of particle number versus particle diameter AEROSIL;

Figure 5. - a) a schematic representation of the hydrophilic part of AEROSIL; b) a schematic representation of the hydrophobic part of AEROSIL.

Nanostructures are represented by AEROSIL particles, on the surface of which there are siloxane and silanol groups. Siloxane groups predominate quantitatively (see FIGS. 4 and 5). Silanol groups give AEROSIL hydrophilic properties. With the help of silane, a chemical modification of AEROSIL is possible. Thus, hydrophobic variants are obtained from hydrophilic AEROSIL, such as, for example, AEROSIL R 972 and R 812. Due to this modification, certain properties are changed, which makes it possible to use AEROSIL in extreme conditions.

AEROSIL is manufactured by hydrolysis of a volatile silicon compound in a flame of explosive gas. Due to appropriate changes in the reaction conditions, the properties of the product are deliberately varied. Special types of AEROSIL are offered for various scopes. AEROSIL consists of spherical particles, which - depending on the type of AEROSIL - have an average diameter between 7 and 40 nm. It is characteristic of the high-temperature hydrolysis process that the particles formed (see FIGS. 5 a and b) are uniform in shape and size. In high temperature flows with various redox potentials, it is possible to obtain nanopowders and their individual inorganic compounds, as well as multicomponent compositions and nanostructures used in the manufacture of building compositions.

Aluminosilicate microspheres (hereinafter referred to as microspheres for short) are formed during the combustion of coal at thermal power plants and are part of fly ash. By their properties, microspheres from energy ashes are close to hollow microspheres, which are obtained from melts by industrial methods. It is very important that the cost of hollow microspheres of spheres extracted from the ash of thermal power plants is several times lower than that obtained by industrial methods. The microspheres have a shape close to spherical and a smooth outer surface (see figure 1.). The diameter of the microspheres varies from 5.0 to 500.0 microns. The gas phase, preserved inside the microspheres, consists mainly of nitrogen, oxygen and carbon monoxide.

The combination of unique properties of microspheres: low density, small size, spherical shape, high hardness and melting point, chemical inertness determine a huge range of applications of microspheres in modern industry.

Advantages of using microspheres:

The spherical (surface-optimal) shape determines the lower need for resins, cement, water, etc. for its wetting than for any other form of filler. This provides a reduced consumption of resins or hardeners, which, in turn, makes it possible to use mixtures with a high solid content, as well as reduce shrinkage deformation and often reduce economic costs.

The microspheres provide a high flowability of the composition so that they are easy to spray, pump, apply with a spatula, etc. Microspheres reduce shrinkage deformation, not only because they allow the use of a lower content of the fastener, but also, directly, due to its shape. At a high concentration, the microspheres are compacted compactly and further compaction does not occur, as can happen with irregularly shaped fillers during shrinkage of the fastener, as well as evaporation of the solvent or water. Thus, the use of microspheres helps to preserve the volume of the original product and, therefore, they are excellent fillers for mastics, for sealing cracks, joints and sealants, etc.

Lightness - the advantages of low density are obvious: at a density of 0.7 g / cm ^{3, the} density of the microspheres is approximately 25% of the density of other mineral fillers, but the microspheres retain sufficient strength to withstand the necessary processes of mixing, additives and processing. Low density provides ease of use, greater ease of mixing, ease of sandblasting, reduced transportation costs, low drawdown and skew, ease of cutting and drilling.

Microspheres have a very low reactivity. Their chemical composition provides high resistance to acids and alkalis. They are pH neutral and do not affect the chemical composition during the reaction of materials or products in which they are used.

The free flowability of the microspheres means that the composition is easy to use in production conditions, it is easy to feed by gravity without fear of clogging, and in dry form it can be pumped or pneumatically transported.

Microspheres have low thermal conductivity of the order of 0.1 W / m-1K.-1. In this regard, it (composition) is widely used as an insulating material for refractory ceramics, oil pipelines, geothermal cements, finishing and stucco gypsum to insulate the external walls of buildings and in many other cases when good thermal insulation is required.

Microspheres have a high melting point of the order of 1200-1600 ° C, which is significantly higher than the melting temperature of synthetic glass microspheres. Therefore, the composition is widely used for the production of high-temperature insulating refractory ceramics, as well as refractory coatings.

The hard surface of the microspheres provides their high resistance to erosion. The vitreous shell of the microspheres is completely impervious to liquids and gases.

Microspheres are used to create heat-insulating radiolucent ceramics. Such ceramics have increased strength, low bulk density, low thermal conductivity and high radio transparency (20-30% higher than for fused silica ceramics).

The chemical composition of the microspheres: SiO ₂ - 55-65%, Al ₂ O ₃ - 25-33%, Fe ₂ O ₃ - 1-6%, CaO - 0,2-0,6% , MgO - 1-2%, K ₂ O - 0.2-4%, Na ₂ O - 0.3-2%, TiO ₂ - 0.5-1%.

Areas of use:

Oil industry: grouting materials for oil wells, drilling fluids, crushing materials and explosives.

Construction: ultralight concrete, mortar, mortar, cement, plaster, coatings, roofing and soundproofing.

Ceramics: refractory materials, refractory bricks, coatings, insulation materials.

Plastids: nylon, polyethylene, polypropylene, etc. Automotive: composites, tires, components, soundproof materials.

Bentonite clays are obtained by drying and fine crushing, they are added to the composition of polymeric materials, mixed with concrete, which increases their water-adhesive properties. This material is very convenient in operation and can be used in almost any weather conditions, including at freezing temperatures. This mineral formation belongs to the class of aluminosilicates having a high dispersion, i.e. having a crystal size of less than 1 μN and, therefore, having a large specific surface. The specific features of the crystal-chemical structure determine the presence of ion-exchange cations on their surface, which strongly affect the physicochemical properties of minerals. The waterproofing board, which contains bentonite clay, has a long service life, withstands an almost unlimited number of hydration-dehydration cycles and easily tolerates the change of seasons. An important property of a waterproofing screen made of bentonite clay is that the material is independently restored in case of damage. The introduction of the optimal amount (2.0 - 8.0%) of bentonite clay into the composition ensures the achievement of a technical result.

The produced white needle wollastonite filler MIVOLL is a purified natural calcium metasilicate fractionated during the production process (see FIG. 2). Being almost universal in chemical composition, it is subjected to special processing methods:

- for the formation of narrow particle size classes with the maximum preservation of high characteristic ratios characteristic of the feedstock - as a rule, at least 10: 1. Grade "97" is the most "long-needle" brand MIVOLL with increased whiteness. Grade “96” - these are mostly “powder” grades;

- to obtain granular discharge forms that facilitate the dosage and introduction of MIVOLL into polymer systems;

- for the production of sizing grades MIVALL, improving adhesion properties, lyophilicity, dispersibility, strength characteristics, etc.

MIVALL wollastonite gives special resistance to UV radiation and water resistance to materials using it, has a biocidal effect, does not contain asbestos-forming substances, is not carcinogenic and is classified as safe, provides a pronounced reinforcing effect in compositions operated under conditions of deformation, alternating, abrasive loads . Main applications: paint and varnish and critical building materials, plastics, rubber and friction products, porcelain and earthenware ceramics, metallurgical and electrode production.

In ceramics: the use of MIVALL wollastonite increases the strength of the product, reduces air and fire shrinkage, defect formation on the surface, allows you to control the dullness and saturation of color tones, is an effective source of calcium.

Mineral composition: wollastonite \ metasilicate \ of two structural polytypes 1TR and 2M.

Chemical composition: CaO - 45-48%, SiO ₂ - 50-53%, Fe ₂ O ₃ - 0.05-0.2%, Al ₂ O ₃ - 0.1-0.3%, MgO - 0, 4-1.0%.

Physical and other characteristics: density, g / cm ³ - 29, hardness (Mohs) - 4.5-5, refractive index - 1.64, pH - 9.5-10.5, humidity - <0.2 %, loss on ignition - <1.2%, water-soluble substances - <0.3%.

Microcalcite - ground and micronized marble MIKARB series "STANDARD", grade "96", is used as a universal white filler (see figure 3). The raw material is fine-crystalline marble of high natural quality with minimal inclusions of chromophores and other harmful impurities and having excellent estimates of weather, wear resistance.

Areas of use are:

- construction industry - dry and ready-to-use building mixtures, putties, decorative compositions;

- adhesives, sealants, mastics, sealing compositions;

- ceramics, electrodes;

- oil industry.

Mineral composition: crystalline calcium carbonate / calcite, marble / high purity.

Chemical composition: CaCO ₃ - 98-99%, MgCO ₃ - 0.5-1.0%, Fe ₂ O ₃ - 0.05-0.1%, Al ₂ O ₃ - 0.02-0.05% , SiO ₂ - <0.5%, water-soluble salts - <0.2%.

Physical and other characteristics: density g / cm ³ - 2.7-2.75, hardness (according to Mohs) - 2.5-3.0, abrasiveness (ASTM 503-89) - 10.3, refractive index - 1, 59, pH 9.2-9.7, humidity <0.3.

Scope: noise-suppressing material with a specific gravity from 80 kg to 1000 kg per 1 m ³ and thermal conductivity from 0.04-0.08 W / m ² C °, which allows you to adjust the density of this material for its intended purpose.

1. Walls of the structure (foam blocks). Specific gravity from 350-500 kg / m ³ . Mostly monolithic and precast monolithic structures. Option: they use mobile foam complexes 1.5-2 times stronger than prefabricated versions of blocks with light reinforcement. For a building, it is enough to have a wall thickness of 250 mm, which corresponds to a 1000 mm brick wall in terms of thermal conductivity. When using smooth plastic formwork, the walls do not require plastering, which saves considerable money.

2. Flooring floors on ceilings. As a powerful sound insulator. Enough 80-100 mm nanomicroconcrete, which decides to completely soundproof the floors according to the sanitary standards of the Russian Federation for sound insulation. Conventional foam concrete needs 2 times more to achieve the same effect.

3. Interfloor ceilings. Using non-separable formwork and reinforced structures, it is poured with monolithic nanomicropenobeton with a specific density of 500-1000 kg / m ³ . At the same time, the ceiling is the floor of the upper floor and the ceiling of the previous one. This design is a lightweight, powerful thermal and acoustic insulator between floors. Additional sound insulation is not required, which saves significant money.

4. Partitions. Filling the partitions with monolithic nano-micro-concrete with light reinforcement with a specific gravity of 350-500 kg / m ³ and a thickness of 100 mm, a sufficiently strong partition structure is provided, as well as reliable sound insulation between adjacent rooms.

5. Roofing (flat). On reinforced concrete floors with a ramp, nanomicropen concrete is poured. A thickness of 150 mm is sufficient, additional screed and insulation are not required, which is 1.5-2 times cheaper than a roof made from traditional materials used in the construction of a soft roof. Labor costs are 5 times less than when working with traditional materials. The specific gravity of nano-micro-concrete is 250-350 kg / m ³ , which significantly reduces the load on the roof.

6. The roof is pitched. The specific gravity of the composition is 80-200 kg / m ³ . Nanomikropenobeton is poured between the supporting rafters. A thickness of 150 mm is sufficient to provide complete sound insulation.

7. Pipes of heating networks. The specific gravity of the composition is 80-150 kg / m3. The composition is poured into the cavity between the outer waterproof shell and the pipe. It is used as a powerful heat insulator that does not lose its properties during long-term operation (more than 30 years) under the influence of high temperature and soil pressure, as well as in channelless laying. It has no mass loss, and also consists of 100% non-combustible materials, does not shrink under the influence of temperature, which cannot be said about the currently used polyurethane foam, which has a mass loss under the influence of temperature, emits toxic gas and loses strength after 10 years of operation is a combustible material with the emission of toxic gases during combustion.

8. Dome structures of large spans. Using reinforcement up to 500 kg / per 1 m ³ and nano-micro-concrete up to 1200 kg per 1 m ³ , it is possible to build dome structures up to 50 m, because the composition has a low specific gravity and great strength up to 300 kg / cm ² .

The invention is illustrated by examples of its implementation.

Example 1

Cement M-500 in an amount of 20 wt.%, Bentonite clay - 2.0%, microspheres - 3.0%, foaming agent - 1.0% and water - 3.0% were mixed. Then a mixture of silicon nanostructures AEROSIL - 2.0%, MIVOLL "97" - 2.0%, MIKARB "STANDARD" "96" - 2.0% was added, the resulting composition was thoroughly mixed until a homogeneous composition was poured into molds. The composition solidified under normal conditions.

Example 2

Cement M-500 in the amount of 35 wt.%, Bentonite clay - 4.0%, microspheres - 10.0%, foaming agent - 2.0% and water - 5.0% were mixed. Then a mixture of silicon nanostructures AEROSIL - 4.0%, MIVOLL "97" - 3.0%, MIKARB "STANDARD" "96" - 3.0% was added, the resulting composition was thoroughly mixed until a homogeneous composition was poured into molds. The composition solidified under normal conditions

Example 3

Cement M-500 in the amount of 45 wt.%, Bentonite clay - 8.0%, microspheres - 20.0%, foaming agent - 4.0% and water - 10.0% were mixed. Then ATROSIL nanostructures were added - 5.0%, MIVOLL-97 - 5.0%, MIKARB-STANDART -96 - 8.0%, the resulting composition was thoroughly mixed to obtain a homogeneous composition, which was poured into molds. The composition solidified under normal conditions.

Example 4

Cement 75 wt.%, Bentonite clay 8.0%, microspheres - 25%, foaming agent - 4.0% and water - 15.0% were mixed. Then a mixture of AEROSIL nanostructures - 5.0%, MIVOLL-97 - 5.5% and MIKARB STANDART -96 - 5.0% were added.

With a low content of mineral binder and filler and the need to increase the volume of the composition, the flow of foaming agent was increased.

The obtained samples of the composition according to examples 1-4 ensured the achievement of the technical results of the invention: high strength combined with high technological properties of building materials, namely an environmentally friendly product with increased lightness, free flowability, fire resistance, seismic resistance, low reactivity and low thermal conductivity. The presented combination of ingredients of the composition provides a synergistic effect. At the same time, going beyond the indicated optimal limits for the content of the ingredients of the composition leads to a weakening of these high technological properties

Claims (1)

Composition for producing building materials containing a mineral binder, fillers, water and nanomaterials, characterized in that as a mineral binder contains cement M-500 and bentonite clay, filler - aluminosilicate microspheres (Al ₂ O ₃ ) with a diameter of 5.0-500 microns , as nanomaterials additionally contains the microstructure of the needle wollastonite filler MIVALL 97, purified by natural calcium silicate, and fractional microcalcite MIKARB "STANDARD" -96 and blowing agent PB-2000, in the following enii, wt.%:
Bentonite clay 2.0-8.0 Aluminosilicate microspheres with a diameter of 5.0-500.0 microns 3.0-25.0 MIVALL-97 1,5-5,5 MIKARB "STANDARD" -96 2.0-8.0 Silicon nanostructures AEROSIL 2.0-5.0 PB 200 foaming agent 1.0-4.0 Water 3.0-15 Cement M-500 Rest

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