RU2477716C1 - Mixture for producing autoclaved cellular concrete - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to construction materials and particularly to autoclaved lightweight concrete. The mixture for producing autoclaved cellular concrete, which contains portland cement, ground unslaked lime, sludge with density of 1.6 kg/ and specific surface area of 290 m²/kg, obtained by combined wet grinding of sand and wastes - scrap foam formed when stripping and sorting finished foam blocks, a protein and water based foaming additive, additionally contains nepheline sludge ground to specific surface area of 430 m²/kg, with the following ratio of components, wt %: portland cement 33.49-37.75, said nepheline sludge 5.46-6.23, said lime 2.77-3.15, sand 25.33-26.5, said foaming additive 0.37-0.39, said wastes 5.8-7.4, water 22.52-22.84.

EFFECT: high frost resistance and quality class of the obtained articles.

1 ex, 2 tbl

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 on a protein basis 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, a complex foam-forming additive on a protein basis - 0.4-0.7, water - 25.4-26.7 (RU No. 2205814, C04B 38/10, 05/06/2002).

Closest to the claimed mixture is a mixture for the manufacture of autoclaved foam concrete, consisting of cement, lime, sand, waste - foam, water, a foam-based additive on a protein basis in the following ratio of components, wt.%: Cement - 26.78-30.78, lime - 5.55-6.3, sand - 25.33-26.50, waste - foam - 5.8-7.4, foam-based additive on a protein basis - 0.37-0.39, water - 32, 17-32.63 (RU No. 2394795, C04B 38/10, 05/04/2009).

The disadvantages of these mixtures are insufficiently high physical and mechanical indicators - frost resistance and quality category of the obtained products.

The objective of the invention is the creation of a new mixture, providing autoclaved foam concrete with improved physical and mechanical characteristics, namely increased frost resistance and quality category of the resulting products.

This object is achieved in that the mixture for autoclaved foam concrete, including cement, lime, sand, waste - foam, a protein-based foam-forming additive and water, contains Portland cement as cement, quick-ground lime, sludge with a density of 1.6 kg / l s a specific surface area of 290 m ² / kg, wet milling the resulting joint sand with waste-penoboem formed during disassembly and sorting of finished foam blocks and further it contains as binder nepheline slurry, milled to a specific surface of 430 m ² / kg, etc. the following component ratio, wt.%:

Portland cement  33.49-37.75 specified nepheline sludge  5.46-6.23 specified lime  2.77-3.15 sand  25.33-26.5 specified foaming additive  0.37-0.39 specified waste  5.8-7.4 water  22.52-22.84

EXAMPLE OF SPECIFIC PERFORMANCE

Production of autoclaved foam concrete

1. Preparation of raw materials.

- joint wet grinding of sand with waste - foam, formed during the dismantling and sorting of finished foam blocks, with the receipt of slurry density of 1.6 kg / l and with a specific particle surface of 290 m ² / kg,

- grinding nepheline sludge to a specific surface of 430 m ² / kg.

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

- sludge with the specified parameters;

- water in accordance with GOST 23732-79;

- quicklime ground powder with a quenching rate of up to 8 min and containing active calcium oxide and magnesium oxide of at least 70%, “burn-out” of no more than 2% with a specific particle surface of 610 m ² / kg;

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

- nepheline sludge, consisting of up to 75% of dicalcium silicate, the chemical composition is shown in table 1.

Table 1 The content of oxides in terms of dry matter,% one 2 3 four 5 6 7 8 9 10 SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Cdo MgO SO ₃ K ₂ O p.p.p. Na ₂ O TiO ₂ 26.29 3.30 3.71 50.57 1,56 0.65 0.70 11.03 1,64 0.39

3. Mixing the raw materials in the mixer.

4. Porization of the mixture due to separately prepared foam from a solution of a foaming additive. The following brands can be used as a foaming additive: Addiment SB 31L (trademark RENIMENT SB 31L, manufacturer SIKA ADDIMENT GmbH В-69171 Leimen, Germany, base - protein hydralizates, dark brown liquid, foaming pH range: 6-10 (Khitrov A.V., abstract for the degree of Doctor of Technical Sciences “Technology and properties of foam concrete, taking into account the nature of the foam introduced.” St. Petersburg, PGUPS, 2006), “FoamCem” (the main active substance is proteine hydrolyzate ; scope: foaming agent for the preparation of lightweight cellular concrete; manufacturer Laston Italiana SPA), Neopor (manufacturer of Neopor System GmbH, Germany, protein base, dark liquid, surface tension 45-55 J / m ² , foaming pH range: 6-8 (Khitrov A.V., abstract for competition academic degree of candidate of technical sciences “Obtaining modern autoclaved foam concrete, taking into account the nature of the introduced building foams.” St. Petersburg, PGUPS, 2000).

5. Transportation of the foam mixture into the holding chamber and its laying in the molds.

6. Exposure of foam arrays to a set of cutting strength of about 0.028 MPa.

7. Cutting foam arrays into products.

8. Autoclave processing of products.

9. Samples of foam concrete products after autoclaving are subjected to frost tests according to GOST 31359-2007 and their quality category is assessed according to GOST 31360-2007, the results are presented in table 2.

An analysis of the results shows that autoclaved foam concrete based on the proposed composition has increased frost resistance and I (highest) quality category of the products obtained.

Claims (1)

A mixture for autoclaved foam concrete, including Portland cement, quicklime powder, sludge with a density of 1.6 kg / l and a specific surface area of 290 m ² / kg, obtained by joint wet grinding of sand with waste - foam, formed during the dismantling and sorting of finished foam blocks, a foaming additive on protein-based and water, characterized in that it additionally contains nepheline sludge, ground to a specific surface of 430 m ² / kg, in the following ratio, wt.%:
Portland cement 33.49-37.75 specified nepheline sludge 5.46-6.23 specified lime 2.77-3.15 sand 25.33-26.5 specified foaming additive 0.37-0.39 specified waste 5.8-7.4 water 22.52-22.84