RU2631124C1 - Complex additive - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: complex additive comprises, wt %: talc 82.3-84.9, silicic acid sol 4.6-6.0, a foaming additive based on protein 1.3-1.5, eighteen-hydrate aluminium sulfate 9.2-10.2.

EFFECT: low coefficient of thermal conductivity.

1 tbl, 1 ex

Description

The invention relates to building materials and can be used as a complex additive in the mortar mixture in the production of foam concrete.

Known complex additive in mortar mixtures containing amylose and sol of silicic acid (RU No. 2278839, C04B 22/08, publ. June 27, 2006).

Closest to the proposed invention is a complex additive containing a sol of silicic acid, a foaming additive based on protein and sodium chloride in the following ratio, wt. %: sol of silicic acid - 20.4-29.4, a foam-based additive on a protein basis - 8.2-11.8, sodium chloride - 58.8-71.4 (RU No. 2381192, C04B 24/14, publ. 02/10/2010).

The disadvantage of such complex additives is an insufficient physical and mechanical indicator: the coefficient of thermal conductivity of the resulting foam concrete.

The objective of the invention is to reduce the coefficient of thermal conductivity of foam.

The technical result of the invention is achieved in that a complex additive for a foam concrete mixture containing a silica sol and a protein-based foam-forming additive additionally contains talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ) and eighteen-aluminum aluminum sulfate (Al ₂ (SO ₄ ) ₃ ⋅18H ₂ O) in the following ratios of components, wt. %:

talc 82.3-84.9 silicic acid sol 4.6-6.0 foaming agent protein based 1.3-1.5 aluminum sulfate eighteen 9.2-10.2

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.

Concrete example

The complex additive for the foam concrete mixture is added to the foam concrete mixture in the following ratios of components, wt%:

talc 82.3-84.9 silicic acid sol 4.6-6.0 foaming agent protein based 1.3-1.5 aluminum sulfate eighteen 9.2-10.2

The following brands can be used as a protein-based foaming additive: Addiment SB 31L (dark brown liquid, foaming range: 6-10; the main active substance is proteine hydrolyzate (Khitrov A.V. so-called “Technology and properties of foam concrete, taking into account the nature of the foam introduced.” St. Petersburg: PGUPS, 2006); application: as an additive for the production of foam concrete; trademark RENIMENT SB 31L; manufacturer SIKA ADDIMENT GmbH В -69171 Leimen, Germany), as well as "FOAMCEM" (the main active substance is proteingid Rolizate; scope: foaming agent for the preparation of lightweight cellular concrete; manufacturer Laston Italiana SPA) and GreenFroth-P (the main active substance is protehydrolyzate; scope: for the production of foam concrete, as well as for the manufacture of light wall and finishing; manufacturer ISOLTECH snc di Scarpa & C ”Via C. Colombo, 41 24020 RANICA (BG), Italy).

To the cement mixture composition, wt. %: Portland cement grade M400-D20 - 80%, siliceous aggregate - 8.5% add the specified complex additive for foam concrete in the amount of 29% by weight of cement, while talc is introduced to the mixture of cement and aggregate in the amount of 11.5% by weight cement, aluminum sulphate eighteen is introduced into the mixing water in an amount of 3.5% by weight of cement with a water-binding ratio (W / B) of 0.37. The resulting mixing water is introduced into the cement mixture. Addiment SB 31L, a protein-based concentrated foaming additive, is dosed in an amount of 0.49% by weight of cement, silica sol with a percentage concentration of silica of 26.7% in an amount of 1.8% and water in an amount of 15.5% by weight of cement is mixed in a plastic container and get a solution of a foaming additive. Using a foam generator, building foam is obtained. The resulting construction foam is mixed with the prepared mortar until a homogeneous foam concrete mixture is obtained.

Samples of medium density foam D500, made with the proposed complex additive for foam concrete, harden under natural conditions.

The determination of the coefficient of thermal conductivity was carried out at the age of 28 days in accordance with GOST 7076-99. The results are presented in the table. The analysis of the results suggests that the introduction of the specified complex additives for the foam concrete mixture leads to a decrease in the coefficient of thermal conductivity of foam concrete in comparison with the values achieved when using the prototype.

Claims (2)

A complex additive comprising a silica sol, a protein-based foaming additive, characterized in that it additionally contains talc and aluminum eighteen-sulfate in the following ratio, wt.%: talc 82.3-84.9 silicic acid sol 4.6-6.0 protein-based foaming agent 1.3-1.5 aluminum sulphate eighteen 9.2-10.2