RU2197451C2 - Method of producing raw material mix for manufacture of unsteamed foam concrete - Google Patents

Abstract

FIELD: manufacture of building materials, particularly, warmth-keeping jacket for building structures. SUBSTANCE: method includes separate preparation of foam from foaming agent, water and cement setting accelerator; introduction of polymer modifying additive into foam; preparation of cement mortar from cement, filler, fibrous filler and additives in the form of initiator and accelerator of polymer setting, and water; activation of said mortar and subsequent mixing of foam and cement mortar. Raw material mixture contains the following ratio of components, mas.%: cement, 35-65; filler, 0-30; fibrous filler, 0-8; cement setting accelerator, 0.3-1.6; foaming agent, 0.4-0.85; polymer modifying additive, 0.5-10.0; polymer setting initiator, 0.15-0.30; polymer setting accelerator, 0.2-3.5; water, the balance. Foaming agent is used in the form of sodium salts of secondary alkyl sulfates or oxide of alkyl dimethylamine. Setting accelerator is used in the form of alkali metal salts - potassium or sodium sulfate, or sodium fluoride, or sodium fluosilicate. Modifying additive is used in the form of acrylic emulsions of copolymers of styrene, acrylic and metacrylic monomers, acrylates and metacrylates in ratio of 1(:0.15-0.35) to setting initiator. Said additive is introduced in amount of not more 5 mas.% of dry matter. Setting initiator of acrylic copolymers is sodium or potassium methyl siliconate, and their setting accelerator is lime or sodium water glass. EFFECT: reduced density, higher strength of concretes, reduced sorption moistening of material. 9 cl, 2 tbl

Description

 The invention relates to the field of building materials industry, namely the production of insulation for building structures - walls, ceilings, coatings, etc., by preparing and pouring foam mass in building conditions or using heat-insulating plates (blocks) made in the factory.

A known method of preparing a non-shrinking aerated concrete mixture to obtain products from non-autoclaved aerated concrete of increased strength, according to which separate preparation of a cement mortar and foam is made, after mixing, aerated concrete mixture is obtained [1]. The disadvantages of this method are the complexity of the process, the inability to obtain foam with a density of less than 400 kg / m ³ , increased hygroscopicity and water absorption.

Also known is a raw material mixture for the manufacture of quick-hardening foam concrete containing Portland cement, ash, foaming agent, aluminum sulfate, semi-aquatic gypsum, alkali metal carbonate, calcium chloride and water [2]. A disadvantage of the known technical solution is the multicomponent formulation and the high density of foam concrete (550-990 kg / m ³ ).

 An object of the invention is to obtain a quick-hardening mixture for the preparation of non-autoclaved foam concrete, reducing the density, increasing strength, reducing the sorption moisture of the material for use in the form of plates (blocks) or filling foam in construction as an effective thermal insulation of building structures, walls, roofs.

 The solution to the technical problem is achieved by the fact that the method of obtaining the raw material mixture for the manufacture of non-autoclaved foam concrete involves the separate preparation of foam from a foaming agent and water, the preparation of a cement mortar from cement, aggregate, additives and water, followed by mixing the foam and cement mortar, and an accelerator is additionally introduced in the preparation of foam hardening of the cement, and a modifying polymer additive is introduced into the finished foam; in the preparation of the cement mortar, initiato is used as additives p curing the polymer and the polymer curing accelerator, a fiber filler is additionally introduced, after preparation, said solution is activated, and the raw mixture contains components in the following ratio, wt. %: cement - 35-65, aggregate - 0-30, fibrous filler - 0-8, cement hardening accelerator - 0.3-1.6, foaming agent - 0.4-0.85, modifying polymer additive - 0.5 -10.0, polymer curing initiator - 0.15-0.30, polymer curing accelerator - 0.2-3.5, the rest is water; as a foaming agent, sodium salts of secondary alkyl sulfates or alkyldimethylamine oxide are used, alkali metal salts (potassium sulfate, sodium sulfate, sodium fluoride, sodium silicofluoride) are used as an accelerator for cement hardening, acrylic emulsions of styrene, acrylic and methylene methylene copolymers are used as a modifying polymer additive esters of acrylic and methacrylic acids in relation to the curing initiator of acrylic copolymers 1: (0.15-0.35), as the initiator Denia acrylic copolymer solution using sodium or potassium methylsiliconate as acrylic copolymers used curing accelerators lime or sodium water glass, acrylic copolymers is administered in an amount not exceeding 5 wt.% solids. At the same time, sodium or potassium methylsiliconate plasticizes the cement mortar and reduces its water-cement ratio, and after curing the foam concrete hydrophobizes its structure.

 As a foaming agent, the Progress preparation is used - sodium salts of secondary alkyl sulfates (TU 38-10719-82), or alkyldimethylamine oxide (TU 2413-016-131644-01-95).

 The modifying additive of the polymer is introduced in an amount of not more than 5% dry matter to obtain a non-combustible material.

 The raw material mixture for the manufacture of foam concrete is prepared as follows. The cement slurry is activated, including water, cement, aggregate, fibrous filler and additives, for example, in a rotary type activator. In the foam obtained in the foam generator from the foaming agent, water and cement hardening accelerator, a modifying polymer additive is introduced. The resulting foam is mixed with cement mortar in a mixer until a homogeneous mass is obtained. Samples (products) are formed from the mixture obtained, hardening under normal conditions or during heat and moisture treatment. After 28 days, the samples were subjected to physical, mechanical, thermophysical tests and tests for sorption moisture.

 The compositions of the mixtures for examples 1-6 are shown in table 1. Physico-mechanical and thermophysical indicators for examples 1-6, analogue [1], prototype [2] and SNiP are shown in table 2.

As can be seen from tables 1 and 2, the test results of samples of autoclave-free foam concrete obtained from the above formulations confirm that the technical task is to obtain quick-hardening foam concrete, including especially lightweight, with a density of less than 400 kg / m ³ and sorption humidification below the required SNiP values resolved. In this case, the strength characteristics of the tested samples have higher values than the given values of these indicators for analog and prototype.

Literature
1. RU 2139268 C1, 10.10.99.

 2. RU 2136634 C1, 09/10/99.

Claims (8)

1. A method of obtaining a raw material mixture for the manufacture of non-autoclaved foam concrete, comprising separately preparing foam from a foaming agent and water, preparing a cement mortar from cement, aggregate, additives and water, followed by mixing the foam and cement mortar, characterized in that during the preparation of the foam, a hardening accelerator is additionally introduced cement, and a polymer modifying additive is introduced into the finished foam; in the preparation of the cement mortar, the polymer curing initiator and accelerator are used as additives a curing polymer, an additional fibrous filler is added, after preparation, said solution is activated, and the raw mixture contains components in the following ratio, wt. %:
Cement - 35-65
Placeholder - 0-30
Fibrous filler - 0-8
Cement hardening accelerator - 0.3-1.6
Frother - 0.4-0.85
The modifying additive of the polymer is 0.5-10.0
Polymer Curing Initiator - 0.15-0.30
Polymer Curing Accelerator - 0.2-3.5
Water - Else
2. The method according to p. 1, characterized in that as a foaming agent, sodium salts of secondary alkyl sulfates or alkyldimethylamine oxide are used.  3. The method according to p. 1, characterized in that as the accelerator of hardening of cement using alkali metal salts.  4. The method according to p. 3, characterized in that the salts of alkali metals are potassium sulfate or sodium sulfate, or sodium fluoride, or sodium silicofluoride.  5. The method according to p. 1, characterized in that the acrylic emulsions of styrene copolymers, acrylic and methacrylic monomers, esters of acrylic and methacrylic acids in proportion to the curing initiator of acrylic copolymers 1: (0.15-0.35) are used as a modifying polymer additive. )  6. The method according to p. 5, characterized in that a solution of sodium or potassium methylsiliconate is used as the initiator of the curing of the acrylic copolymers.  7. The method according to p. 1, characterized in that as the accelerator of the curing of the polymer using lime or sodium liquid glass.  8. The method according to p. 5, characterized in that the acrylic copolymers are introduced in an amount not exceeding 5 wt. % dry matter.  9. The method according to p. 6, characterized in that the sodium or potassium methylsiliconate plasticizes the cement mortar and reduces its water-cement ratio, and after curing the foam concrete hydrophobizes its structure.

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