RU2624942C1 - Mixture for autoclave foam concrete - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: mixture for autoclave foam concrete, including portland cement, quicklime lime, sand in the form of sand slurry with a density of about 1.6 g/l, obtained by wet grinding to a specific surface of particles of 280-300 m²/kg, foam-based protein-based additive, water and waste-condensate, formed during the autoclave processing of the cut foam concrete massif, additionally contains muscovite, co-grinded with sand wet grinding, ferrous sulfate, at the following ratio of components, wt %: Portland cement 17.00-19.38, mentioned muscovite 1.75-1.95, ferrous sulfate 0.52-0.59, mentioned lime 6.9-7.18, mentioned sand 43.42-45.03, mentioned foaming agent 0.23-0.24, water 19.46-19.61, mentioned waste-condensate 8.34-8.40.

EFFECT: increase in the coefficient of vapor permeability and decrease in the coefficient of thermal conductivity of finished products.

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Description

The invention relates to the field of building materials, in particular to cellular concrete autoclaved.

A known mixture for the manufacture of foam concrete containing cement, sand, lime, water and a complex foaming additive in the following ratio of components, wt.%: C ₁₉ H ₂₉ COONa⋅3C ₁₅ H ₂₉ COOH - 30.34-33.67, KOH - 6 , 88-7.64, glue - 10.67-11.83, water - 34.11-37.86, fatty acid salt - 9.0-18, and the following ratio of the components of the mixture for cellular foam concrete: cement - 38 -42, sand - 28-30, lime - 4.2-4.6, complex foaming additive - 0.4-0.7, water - 25.4-26.7 (RU No. 2205814, С04В 38/10, 05/06/2002).

Closest to the claimed mixture is a mixture for the manufacture of autoclaved foam concrete, consisting of Portland cement, lime, sand, water, a foaming additive and waste condensate in the following ratio of components, wt.%: Portland cement - 17.52-19.90, lime - 6 , 9-7.18, sand - 45.17-47.05, foaming additive - 0.23-0.24, water - 19.46-19.61, waste condensate - 8.34-8.40 ( RU No. 2403232, С04В 38/19, 11/10/2010).

The disadvantage of these mixtures is the lack of physical and mechanical properties: the vapor permeability and thermal conductivity of the finished product.

The objective of the invention is the creation of a new mixture, providing autoclaved foam with improved characteristics, namely with a high coefficient of vapor permeability and low coefficient of thermal conductivity of the finished product.

The technical result is achieved in that the mixture for autoclaved foam concrete containing Portland cement, lime, sand, water, a foaming additive and waste condensate formed during the autoclave treatment of the cut raw foam concrete array additionally contains muscovite KAl ₃ Si ₃ O ₁₀ ( OH) ₂ and ferrous sulfate, seven-water FeSO ₄ ⋅ 7H ₂ O, in the following ratio of components, wt.%:

Portland cement - 17.00-19.38

muscovite - 1.75-1.95

ferrous sulfate seven-water - 0.52-0.59

lime - 6.9-7.18

sand - 43.42-45.03

foaming additive - 0.23-0.24

water - 19.46-19.61

waste condensate - 8.34-8.40

EXAMPLE OF SPECIFIC PERFORMANCE

Production of autoclaved foam concrete

1. Preparation of raw materials

- wet grinding of sand together with muscovite KAL ₃ Si ₃ O ₁₀ (OH) ₂ to obtain a slurry density of about 1.6 g / l with a specific particle surface of 280-300 m ² / kg. Muscovite KAL ₃ Si ₃ O ₁₀ (OH) ₂ includes: silica - 48%, alumina + iron oxide - 40%, potassium oxide - 8%, magnesium oxide - 2%, water - 2%.

- selection of the autoclave condensate formed during the production into metal containers for cooling to t about 20 ° C. The composition of the waste condensate includes calcium (Ca ²⁺ ), magnesium (Mg ²⁺ ), iron (Fe ²⁺ ), iron (Fe ³⁺ ), bicarbonate (HCO ₃ ^- ), ammonium (NH ₄ ⁺ ) ^ions , pH about 13.

2. Dosing and loading into the mixer of raw materials:

- sludge with the required parameters;

- water in accordance with GOST 23732-79;

- liquid waste condensate;

- ferrous sulfate;

- quicklime ground powder with a quenching rate of up to 8 min and containing active calcium oxide + magnesium oxide of at least 70%, “burn-out” of not more than 2%;

- Portland cement PC 400 D0-D20 and PC 500 D0-D20, with a content of tricalcium aluminate C ₃ A of not more than 6%;

3. Mixing the raw materials in the mixer.

4. Porization of the mixture due to separately prepared foam from a foaming agent solution. The following can be used as a foaming agent: a protein-based foaming agent (Addiment SB 31L), which includes protein hydrolysates, density 1.09 kg / l, pH about 7-7.5; a foaming agent based on derivatives of carboxylic acids ("KVIN"), a density of approximately 1.3 kg / l, a pH of about 8-9, and a foaming agent based on resin acids - a glucose rosin foaming agent (KKPO), a density of 1.2 kg / l, pH approximately 8.5-9.5 (Khitrov A.V. Obtaining modern autoclaved foam concrete, taking into account the nature of building foams introduced. Author, dissertation for the participation of the candidate of technical sciences, S-Pb, PSUPS, 2000, p. 9, 15).

5. Transportation with the help of a concrete distributor of foam concrete mixture to the holding chamber and its laying in the molds.

6. Exposure of foam arrays to a set of cutting strength equal to 0.028 MPa, (cutting strength is determined by a plastometer, the time of setting of cutting strength by a raw concrete array is shown in the table).

7. Cutting foam arrays into products.

8. Autoclave processing of products.

9. Samples of foam concrete products after autoclaving are subjected to tests to determine the coefficient of vapor permeability and thermal conductivity according to GOST 31360, the results are presented in the table.

An analysis of the results shows that autoclaved foam concrete based on the proposed composition has increased vapor permeability and a lower coefficient of thermal conductivity compared to the prototype - the improved characteristics correspond to foam concrete with a lower density grade in accordance with GOST 31359-2007.

The achieved effect is due to the fact that the introduced additives have high values of standard entropy, S ⁰ ₂₉₈ , i.e. a high degree of disorder, which contributes to a greater dispersion of the heat wave in foam concrete products and a decrease in their thermal conductivity coefficient, as well as an increase in the vapor permeability coefficient.

Claims (2)

A mixture for autoclaved foam concrete, including Portland cement, quicklime powder, sand in the form of sand slurry with a density of about 1.6 g / l, obtained by wet grinding to a specific particle surface of 280-300 m ² / kg, a protein-based foam-forming additive, water, waste condensate formed during production during autoclaving of the cut raw foam concrete mass, characterized in that it additionally contains muscovite, co-milled with sand and wet grinding, and ferrous sulfate in the following ratio and components, wt.%: Portland cement 17.00-19.38 specified muscovite 1.75-1.95 ferrous sulfate 0.52-0.59 specified lime 6.9-7.18 specified sand 43.42-45.03 specified foaming additive 0.23-0.24 water 19.46-19.61 specified condensate waste 8.34-8.40