RU2303579C1 - Multi-purpose dry cement composition - Google Patents

Abstract

FIELD: manufacture of building materials; manufacture of dry cement composition for masonry.

SUBSTANCE: proposed dry cement composition is used for masonry from cellular concrete blocks, gas-and-ash concrete blocks inclusive and light concretes, it may be also used as putty mixture for external and internal surfaces of buildings and structures from cellular concrete, ceramic and lime-and-sand bricks, expanded-clay lightweight concrete and concrete. Proposed dry cement composition contains Portland cement, calcium-containing component, re-dispersed powder, cellulose ester, modifying additive; used as calcium-containing component is ground marble and used as re-dispersed powder are monomers of vinyl acetate, ethylene, polyvinyl alcohol Mowilith Pulver DM 1142P; used as cellulose ester is Walocer MKX 25000PF50L; used as modifying agent is are water-repellent agents in form of sodium oleate and calcium stearate and additionally lime-and-ash binder, fly ash of Reftinsk steam central power plant, air-entraining component in form of lauryl of sodium sulfate, anti-frothing agent in form of polyglycols of liquid hydrocarbons - Agitan P9=801 and/or superplasticizing agent of form of sulfo-melamine formaldehyde at the following ratio of components, mass-%: Portland cement, 19.00-27.50; ground marble, 10.00-10.50; re-dispersed powder, 1.10-1.80; cellulose ester, 0.20-0.25; sodium oleate, 0.10-0.30; calcium stearate, 0.10-0.30; lime-and-ash binder, 4.50-5.0; fly ash of Reftinsk steam central power plant, 54.75-64.33; air-entraining component, 0.01-0.02; anti-frothing agent, 0.10-0.15 and superplasticizing agent, 0.05-0.10. Lime-and-ash binder may contain lime and ash of Reftinsk steam central power plant at ratio of components of 1:1.

EFFECT: low cost of composition; enhanced ecology due to use of power plant wastes; extended field of application.

2 cl, 2 tbl

Description

The invention relates to the field of building materials, in particular to cement compositions used for masonry work using building blocks of aerated concrete, including autoclaved aerated concrete, as well as expanded clay concrete and other types of light concrete, as well as a putty mixture for finishing alignment of the external and internal surfaces of buildings and structures made of cellular concrete, ceramic and silicate bricks, expanded clay concrete and concrete operating in conditions of periodic moisturizing.

Known dry mortar mixture (see RF patent No. 2204540, 7MPK C04B 26/00, C04B 26/06, C04B 28/00, C04B 28/10, published 05/20/2003), containing binder in the form of Portland cement, aggregate and modifying an additive comprising silica fume, plasticizer, dolomite or limestone flour, water-soluble cellulose ether, a dispersion powder in the form of polyvinyl acetate or acrylate copolymers in the following ratio of components of the modifying additive, wt.%:

Silica fume 0.1-30.0 Plasticizer 0.5-3.0 Dolomite or limestone flour 40.0-92.0 Water soluble cellulose ether 0.1-3.0 Redispersible powder in the form copolymers of polyvinyl acetate or acrylate 0.3-24.0

wherein the aggregate includes wt.%: silica sand 99.9-85.0 with the fineness modulus MKR. not more than 1.5 and dust-like quartz 0.10-15 in the following ratio of mixture components, wt.%:

Astringent 25.0-35.0 Aggregate 55.0-74.0 Modifying additive 1.0-10.0

A disadvantage of the known dry mortar mixture is its high cost, since enriched quartz sand obtained by dividing natural sand into fractions and then mixing certain fractions in a given proportion is used as a filler, which increases the complexity of manufacturing the mixture. In addition, quartz sand must be pre-dried, which is quite time-consuming and costly operation. The market value of sand is 2-3 times higher than the cost of man-made aggregates, such as ash. At the same time, the use of a significant amount of Portland cement (up to 35%) in the composition of the known mixture also increases its cost.

The closest in technical essence is a universal dry cement composition (see RF patent No. 2181705, 7MPK С04В 28/04, published April 27, 2002), including Portland cement, sand (aggregate), limestone or dolomite flour (calcium-containing component), redispersion polyvinyl acetate powder, cellulose methyl ester (cellulose ester), superplasticizer based on sodium salts of the condensation product of aromatic derivatives or melamine, tartaric acid, condensed silica fume and the regulator is solid I (modifying additive) selected from the group of sulfates, or chlorides, or carbonates, or nitrites, or nitrates of alkali and / or alkaline-earth metals, technical modified lignosulfonates, neutralized air-entraining resin, non-trilotrimethylphosphoric acid, or mixtures thereof with a ratio of components, wt .%:

Portland cement 10-70 Sand 85-1.0 Superplasticizer 0.05-1.5 Limestone or dolomite flour 0.5-85 Cellulose Methyl Ester 0.01-2.5 Condensed Silica Fume 0.25-3.5 Polyvinyl acetate 0.01-5.0 Hardening regulator 0.0001-0.9 Wine acid 0.01-0.1

A disadvantage of the known universal dry cement composition, as well as the above analogue, is its high cost, since enriched quartz sand obtained by drying, dividing natural sand into fractions, mixing certain fractions in a given proportion is used as a filler, which increases the complexity of manufacturing the composition. Moreover, the use in the composition of a known composition of a significant amount (up to 70%) of expensive Portland cement grade PC 500 DO and dolomite or limestone flour (up to 85%) also increases its cost.

Despite its versatility, the well-known dry cement composition does not provide sufficient strength and performance characteristics when laying building blocks of cellular concrete, including autoclaved aerated concrete, expanded clay concrete and other types of lightweight concrete, as it does not contain additives to compensate for the shrinkage of cement binder, as well as cannot be used for finishing alignment of the outer surfaces of these materials, since it does not have sufficient water-repellent properties, it is necessary E to protect from moisture porous blocks.

The prior art is the use of fly ash in small quantities in the production of building materials (see USSR author's certificate No. 1724623, 5MPK S04B 26/04 "Polymer concrete mix", published on 04/07/1992). Known polymer concrete mixture contains 7-10% fly ash and is used for the manufacture of chemically resistant products.

Also known is the raw material mixture for the production of lightweight aggregate in the form of granules, followed by heat treatment of 300-400 ° C (see RF patent No. 2214977, 7MPK S04B 18/04, "Raw mix and method of production of lightweight aggregate", published October 23, 2003) where fly ash contains 5.3-6.3%.

Known mixtures cannot be used for the finish leveling of the external and internal surfaces of buildings and structures made of cellular concrete, since they do not provide sufficient adhesive ability and adhesion of the solution to the main material of porous surfaces, which does not allow to provide the necessary strength and deformability of hardened solutions. And even more so, they cannot be used for masonry work using building blocks of cellular concrete, expanded clay concrete and other types of lightweight concrete.

The technical result of the claimed invention provides for reducing the cost of universal dry cement composition, improving the environment through the use of GRES waste, expanding its scope for filling the internal and external surfaces of buildings and structures made of cellular concrete, including autoclaved aerated concrete, expanded clay concrete and other types of lightweight concrete , as well as for masonry building blocks of these materials.

The specified technical result is achieved in that the universal dry cement composition, including Portland cement, aggregate, calcium component, dispersion powder, cellulose ester, modifying additive, according to the invention, includes lime-ash binder, fly ash of Reftinskaya state district power station as a filler, ground marble as a calcium-containing component, a dispersion powder in the form of monomers of vinyl acetate, ethylene, polyvinyl alcohol, and the modifying additive includes hyd offisers in the form of sodium oleate and calcium stearate, as well as anti-foaming agent in the form of polyglycols of liquid hydrocarbons or a superplasticizer in the form of sulfomelamine formaldehyde and an air-entraining component in the form of sodium lauryl sulfate in the ratio of components, wt.%:

Portland cement 19.00-27.50 Calcium ash binder 4.50-5.00 Fly ash of Reftinskaya state district power station 54.75-64.33 Ground marble 10.00-10.50 Redispersible powder in the form monomers of vinyl acetate, ethylene and polyvinyl alcohol 1.10-1.80 Cellulose ester 0.20-0.25 Sodium oleate 0.10-0.30 Calcium stearate 0.10-0.30 Polyglycol Antifoam liquid hydrocarbons 0.10-0.15 Superplasticizer in the form of sulfomelamine formaldehyde 0.05-0.10 Sodium lauryl sulfate 0.01-0.02

At the same time, the lime-ash binder contains lime and fly ash of the Reftinskaya state district power station with a component ratio of 1: 1.

Fly ash of the Reftinskaya state district power station obtained by burning Ekibastuz coal has the following composition, wt.%:

SiO ₂ 58-62 Al ₂ About ₃ 25-30 Fe ₂ O ₃ 5-8 CaO and MgO 3-5 R ₂ O 0.5-0.7 SO ₃ 0.1-0.3 pp 1-2

The fly ash of Reftinskaya TPP, in contrast to the known ones, is characterized by uniformity of properties. It consists of 90% aluminosilicates, with about 30% being silicon oxide (SiO ₂ ), due to which ash has some astringent properties.

Fly ash of the Reftinskaya TPP consists of 70% of the amorphous phase in the form of glass and practically does not contain unburned particles, which are harmful impurities. This increases the activity of fly ash and allows it to be used in the claimed universal dry cement composition in large quantities (up to 64.33%).

The fly ash of the Reftinskaya TPP, which has some astringent properties, can significantly reduce the content of Portland cement in the universal dry cement composition, which reduces the cost of the latter.

In addition, the fly ash of the Reftinskaya TPP, in comparison with quartz sand, is a finely dispersed component with a specific surface area of 3000-3500 cm ² / g that does not require additional drying, grinding and sieving, which also reduces the cost of a universal dry cement composition.

Fly ash of Reftinskaya state district power station according to the sanitary-epidemiological conclusion No. 66.01.08.000.P.001474 issued by TsGSEN of the Sverdlovsk region does not contain radioactive elements and meets all the standards for building materials, including dry mixes.

An important advantage of the claimed composition is that its production contributes to the solution of the environmental problem by reducing ash dumps that pollute the environment.

The introduction of Portland cement ПЦ 400-Д20 in an amount of 19-27.5% provides the necessary strength and performance characteristics of putty coatings and masonry glue. Less than 19% of Portland cement in the composition leads to a decrease in strength characteristics, and more than 27.5% do not give a significant increase in strength, therefore, it is not economically feasible.

The introduction of lime-ash binder in the ratio of lime and ash 1: 1 in an amount of 4.5-5.0% provides compensation for shrinkage of Portland cement. The content of lime-ash binder of less than 4.5% does not fully compensate for shrinkage, and more than 5.0% leads to the effect of expansion of the solution, which is technologically undesirable.

The introduction of 10.0-10.5% ground marble and 54.75-64.33% fly ash of the Reftinskaya state district power station, which has some astringent properties, makes it possible to provide the necessary technological and strength characteristics of a universal dry cement composition for both finish alignment of internal and external surfaces , and for masonry blocks of cellular concrete, including gas-ash concrete autoclaved, as well as expanded clay concrete and other types of lightweight concrete. The content in the composition of fly ash more than 64.33% leads to a decrease in strength and increase the coefficient of water absorption.

The introduction of a redispersion powder (RPP brand Mowilith Pulver DM 1142P) in the form of monomers of vinyl acetate, ethylene, polyvinyl alcohol in an amount of 1.1-1.8% allows the formation of films at the boundary during hardening and as a result of gradual dehydration of the solution from the aqueous dispersion of monomers solution-surface sections serve as glue providing good adhesion of materials. The indicated quantity is optimal for a combination of components with fly ash of Reftinskaya state district power station. The content of this component of more than 1.8% is not economically feasible.

To prevent separation of the mobile solution and water suction from it when applied to the surface, a water-retaining component is introduced into the composition - cellulose ester (Walocel MKX 25000 PF50L brand), containing hydroxyethyl and hydroxypropyl methyl cellulose, in an amount of 0.20-0.25%.

Regulation of the rheological properties of the claimed composition and reduction of water demand is achieved using superplasticizer (brand Melment F10) in the form of sulfomethylamine formaldehyde - a polycondensation product based on melamine formaldehyde, polycarboxylate and polyethylene glycol, introduced in an amount of 0.05-0.10. The introduction of superplasticizer increases the mobility and processability of the solution, significantly reduces water demand and, together with cellulose ester, vinyl acetate, ethylene, polyvinyl alcohol monomers, increases the final strength, density and uniformity of the hardened stone, as well as reduces shrinkage.

To ensure the rheological properties of the solution when the content of the specified component is less than 0.05%, an increase in water is required, which negatively affects the properties of the solution. More than 0.10% is technologically impractical.

Introduction to the composition of water-repellent components in the form of sodium oleate (C ₁₆ H ₃₃ COONa) and calcium stearate (C ₁₇ H ₃₅ COO) ₂ Ca in an amount of 0.10-0.30% of each improves the water-repellent effect when applying the solution on porous surfaces due to reduction of water absorption and vapor permeability, which allows for high manufacturability and durability of the mortar, especially for blocks of cellular concrete, which 60-70% consists of pores, and therefore, a high coefficient of water absorption. The specified number of water-repellent components protects the blocks from moisture and increases the durability of their operation.

Introduction to the composition of the universal dry cement composition used for masonry work, the air-entraining component in the form of sodium lauryl sulfate (brand Esapon 1214) in an amount of 0.01-0.02%, forming in a solution based on Portland cement, marble and fly ash stable pores, acts as a wetting agent and plasticizer, increases the elasticity of the solution, prevents shrinkage and cracking, increases frost resistance and reduces the risk of “efflorescence”.

Universal dry cement composition contains anti-foaming agent (brand Agitan P-801) in the form of polyglycols of liquid hydrocarbons in an amount of 0.10-0.15%, which during puttying can increase the portability of the solution.

The introduction of modern and highly active polymer additives into the universal dry cement composition, which provide the necessary rheological and physico-mechanical properties of the solution, makes it possible, together with Portland cement, marble and calcareous binders, to use the fly ash of Reftinskaya state district power station as a filler, which, along with a reduction in the content of these additives in the volume of the composition significantly reduces the cost of a universal dry cement composition.

Technical solutions that coincide with the totality of the essential features of the invention have not been identified, which allows us to conclude that the invention meets the condition of patentability "novelty".

The claimed essential features of the invention, predetermining the receipt of the specified technical result, do not explicitly follow from the prior art, which allows us to conclude that the invention meets the condition of patentability "inventive step".

The patentability condition "industrial applicability" is confirmed by examples of a specific embodiment of the invention.

The following components are used to prepare a universal dry cement composition: Portland cement ПЦ 400-Д20 in accordance with GOST 10178, fly ash of Reftinskaya state district power station in accordance with GOST 25818, lump lime in accordance with GOST 9179-77, ground marble MM-80 in accordance with TU 5716-009-00281950-2003 .

Preparation of universal dry cement composition is as follows.

Separately, a calcareous-ash binder is prepared with a ratio of lime and fly ash of Reftinskaya TPP 1: 1. Then, in accordance with the specified percentage composition, the components are dosed and combined with a lime-ash binder. Mix the components. The resulting dry cement composition is Packed in standard bags and sent to the consumer.

The solution mixture is prepared as follows.

Dry cement composition is poured into the container and water is added. The water-solid ratio that provides the mortar mixture is 0.50-0.60. They are mixed for 4-5 minutes, kept for 4-5 minutes, and then intensively mixed for 30 seconds. Then the finished putty mixture is applied manually or by machine to the surface. Layer thickness in one pass 1-3 mm. If you need to apply several layers, make sure that the previous layer is dry. The adhesion strength of the solution to the base at the age of 28 days is at least 0.2 MPa. The thickness of the layer of the mounting mortar mixture is 3-5 mm.

Table 1 presents examples of the compositions of the universal dry cement composition.

Table 1
Examples of specific performance of the composition No.
p / p The composition of the components The content of components,% Example 1 Example 2 Example 3 one Portland cement PC-400-D20 19.00 23.40 27,50 2 Fly ash of Reftinskaya state district power station 64.33 59.54 54.75 3 Calcium ash binder 5.00 4,50 5.00 four Ground marble MM-80 10.0 10.50 10.0 5 Redispersion powder in the form of monomers of vinyl acetate, ethylene, polyvinyl alcohol RPP Mowilith Pulver DM1142P 1.10 1,50 1.80 6 Cellulose Ester-Walogel MKX 25000 PF50L 0.25 0.20 0.20 7 Sodium oleate 0.10 0.10 0.30 8 Calcium stearate 0.10 0.10 0.30 9 Antifoaming Agent-Agitan P801-Liquid Hydrocarbon Polyglycols - 0.10 0.15 10 Superplasticizer Melment F10-sulfomelamide formaldehyde 0.10 0.05 - eleven Espoon1214-lauryl sodium sulfate entraining component 0.02 0.01 -

Example 1 shows a mounting adhesive mixture for masonry work using building blocks of cellular concrete, including autoclaved gas-concrete, as well as expanded clay and other types of lightweight concrete

Example 2 shows a putty mixture for finishing leveling the internal surfaces of buildings and structures made of cellular concrete, as well as ceramic and silicate bricks, expanded clay concrete and concrete after preliminary alignment of gross surface defects using leveling cement-lime and cement plasters.

Example 3 shows a putty mixture for the finish leveling of the internal and external surfaces of buildings and structures made of cellular concrete, including autoclaved aerated concrete, operated under periodic wetting conditions. The putty mixture can also be used to finish leveling surfaces of ceramic and silicate bricks, expanded clay concrete and concrete, after preliminary leveling of rough surface defects with the help of leveling cement-lime and cement plasters.

Table 2 shows the technical characteristics and test results of the claimed compositions of the universal dry cement composition.

table 2
Specifications and Test Results No.
p / p Name of indicator Units measuring Example 1 Example 2 Example 3 one Bulk density kg / m 700-790 720-760 730-830 2 Mixing water consumption l / kg 0.41-0.48 0.45-0.52 0.40-0.50 3 Mortar mobility mm 68-70 68-70 68-70 four Material consumption with a layer of 1 mm kg / m ² 1,5 1,6 1.7 5 The time of use of the mortar mixture, not less hour 2.0 1,5 1,5 6 Adhesion to base, not less than MPa 0.2 0.2 0.2 7 Application temperature ° C + 5 ÷ + 35 + 5 ÷ + 35 + 5 ÷ + 35

Claims (2)

1. A universal dry cement composition including Portland cement, a calcium-containing component, a dispersion powder, cellulose ester, a modifying additive, characterized in that it contains ground marble as a calcium-containing component, and monomers of vinyl acetate, ethylene, polyvinyl alcohol - RPP as a dispersion powder Mowilith Pulver DM 1142P, as a cellulose ester - Walocel MKX 25000PF50L, as a modifying additive - water repellents in the form of sodium oleate and calcium stearate and additionally ash-ash binder, fly ash of Reftinskaya state district power station, air-entraining component in the form of sodium lauryl sulfate, antifoam in the form of liquid hydrocarbon polyglycols - Agitan P801 and / or superplasticizer in the form of sulfomelamine formaldehyde in the following ratio, wt.%: Portland cement 19.00-27.50 ground marble 10.00-10.50 specified redispersion powder 1.10-1.80 specified cellulose ester 0.20-0.25 sodium oleate 0.10-0.30 calcium stearate 0.10-0.30 lime-ash binder 4.50-5.00 fly ash of Reftinskaya state district power station 54.75-64.33 specified air-entraining component 0.01-0.02 specified antifoam 0.10-0.15 specified superplasticizer 0.05-0.10 2. The universal dry cement composition according to claim 1, characterized in that the lime-ash binder contains lime and fly ash of the Reftinskaya state district power station with a component ratio of 1: 1.