RU2458879C1 - Foaming agent for making foamed concrete - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of construction materials and can be used in production of foamed concrete. The foaming agent for making foamed concrete contains the following in wt %: sodium alkylbenzene sulphonate 0.03 - 0.20, sodium chloride 2, chalk with specific surface area 450 m²/kg 3, engine oil 1-3, water - the balance.

EFFECT: high expansion rate and stability of foam, low density of foamed concrete without significant loss in strength.

1 ex, 1 tbl

Description

The invention relates to the construction materials industry and can be used in the production technology of cellular concrete.

Known foaming agent for the preparation of cellular concrete, including as a surfactant - saponified wood pitch in an amount of 3-6%, and as a foam stabilizer - clay powder in an amount of 16-18 wt.% [SU No. 1152946, С04В 28/02, 1985] . The main disadvantage of this foaming agent is the increased water demand and, as a result, the high average density of foam concrete products.

The closest to the present invention is a foaming agent for the manufacture of cellular concrete containing sodium surfactant alpha-olefinosulfonate (AOC) in the amount of 0.04-0.12 wt.%, Water, and various foam stabilizers additives: casein glue - 0.02-0.20 wt.%, waste from the glycerin industry - 0.011-0.110 wt.%, hydrolyzed proteins - 0.004-0.024 wt.%, etc. [RU 2199509, С04В 38/10, 2003] .

The main disadvantage of this foaming agent is the low multiplicity of the foam, which leads to an increase in the density of foam concrete products, and the invaluable stability of the obtained foam over time, because these indicators are most important when assessing the interaction of foam with a binder (cement). It should also be noted the minimum number of foam stabilizers introduced into the composition of the foaming agent, which makes it difficult to dispense them on a production scale.

The objective of the present invention is to increase the multiplicity and stability of the foam and, as a consequence, reduce the average density of aerated concrete without significant loss of strength of the products.

The problem is achieved in that additives - activators of the foaming process and additives - stabilizers of the foam, are introduced to the aqueous solution, which is a surfactant, sodium alkylbenzenesulfonate (ABS). Sodium chloride is used as an activator of foaming, and chalk with a specific surface of 450 m ² / kg and engine oil are used as foam stabilizers in the following ratio of components, wt.%:

ABS - 0.03-0.20

Sodium Chloride - 2

Chalk - 3

Engine oil - 1-3

Water - The rest.

Execution example. The working solution is prepared in the following sequence: sodium alkylbenzenesulfonate (ABS) is mixed with machine oil, water and sodium chloride are added to the resulting solution. Pre-prepared chalk is added to the activated foaming solution, then this whole mixture is foamed in a rotary type mixer for 2 minutes at a speed of 600-800 rpm, after which the main indicators of the quality of the foam (multiplicity, foam resistance, etc.) are determined.

For experimental verification of the inventive foaming agent were prepared 12 mixtures of four with each activator and foam stabilizers (see table).

From the table it follows that the foaming agents of the proposed composition (1-12) for the manufacture of cellular concrete have a significantly higher foam ratio, which can significantly reduce the density of foam concrete products without significant loss of strength.

A comparative analysis with the prototype allows us to conclude that the inventive foaming agent differs from the known using new components as an activator and stabilizers, namely sodium chloride, engine oil and chalk. The use of these additives makes it possible to increase the multiplicity and resistance of foam systems by influencing these additives on the basic rheological characteristics of a surfactant, namely, viscosity and surface tension. The addition of sodium chloride to a surfactant reduces its viscosity and increases surface tension, i.e. directly affects the degree of colloidy of its aqueous solution. When mixed, additives, stabilizers, chalk and engine oil themselves form a colloidal system, which, when preparing the foam, is evenly distributed along the Plateau-Gibbs channels, and, concentrating in the nodes, increases the viscosity of the surfactant solution, and thereby reduces the self-destruction of the foam over time.

In addition, the use of the above substances allows you to control the process of structure formation, while obtaining finely porous foam concrete with prevailing closed porosity, which reduces water demand and, as a result, reduces the average density of foam concrete products.

On the basis of the foaming agent, the proposed composition, it is possible to obtain various products from foam concrete, which can be used as building and heat-insulating material in the construction and thermal insulation of various civil and industrial facilities.

Claims (1)

Foaming agent for the manufacture of cellular concrete, including a surfactant, foam stabilizers and water, characterized in that it contains sodium alkylbenzenesulfonate - ABS as a surfactant, and chalk with a specific surface area of 450 m ² / kg and machine oil and additionally contains a foam activator - sodium chloride in the following ratio of components, wt.%:
ABS 0.03-0.20 Sodium chloride 2 a piece of chalk 3 Machine oil 1-3 Water Rest