DE102009052435A1 - Raw material mixture for autoclave aerated concrete, consists of cement, sand, agent producing protein-containing foam, ash- and slag residues from solid fuel combustion, sodium fluoride additive and water - Google Patents

Abstract

The raw material mixture for autoclave aerated concrete, consists of cement (48.54-49.60 wt.%), sand (5.82-6.23 wt.%), agent producing protein-containing foam (0.34-0.36 wt.%), ash- and slag residues (14.90-15.10 wt.%) from solid fuel combustion with specific surface of 300 m 2>/kg, sodium fluoride additive (0.21-0.24 wt.%) and water (29.13-29.53 wt.%).

Description

The invention relates to a raw material mixture for Autoklavebeton according to the preamble of the claim.

The invention can be used in the field of building materials. It can be used in particular for the production of products suitable for industrial and civil engineering.

From the patent RU No. 2145315 (C04B 38/10, 02.03.1999) is a mixture for thermal insulation foam concrete, the following ingredients (in wt .-%):
Cement - 43.0-46.2;
fine flour slag [with a Fe (II) content of max. 4%] - 12.0-14.4;
Sand - 18,0-15,0;
a foam-forming agent [based on sodium stearate having a density of 1.15-1.77 g / cm ³ ] - 9.5-10.3;
a chemical additive "DEA", which contains a post-mortar and modifier. The modifier is a blown porous product having a density of 0.5 g / cm ³ in an amount of (wt.)% 3.0-0.5. This product contains calcium and magnesium silicates - 0.4-0.54, aluminum powder - 0.5-0.64; Fiber Fiber - 1.4-1.8; Water - 12.0-14.4.

The deficiencies of the above mixture are insufficient compression strength, increased thermal conductivity, and low vapor transmission rate.

From the patent RU No. 2306300 (C04B 38/10, 20.09.2007) a mixture for a foam concrete is known, which has the following composition (wt .-%):
Cement - 51.88-56.52;
Lime - 1.57-2.06;
Sand - 9.84-10.25;
Ashes left over from sewage sludge incineration - 6,41-7,36;
Hemihydrate gypsum (CaSO ₄ .5H ₂ O) - 1.05-1.54;
Plastic fibers - 0.15-0.17;
a 20% brine solution of orthosilicic acid at pH 3.1-4.0 - 0.03-0.04;
a foam-producing agent - 0.18-0.27;
Water - 24.25-26.43.

The shortcomings of this known mixture consist in an insufficient compression strength, an increased thermal conductivity and a low vapor transmission rate.

The state of the art as the prototype of the notified mixture, which first appears in the application, is a mixture for autoclave foam concrete having the following composition (wt.)%: Cement - 37.8-42.6; Sand - 31.3-37.8; modified proteinaceous foam-forming agent - 9,1-9,3 and water - 15,1-17,0 [ RU No. 2255074 , C04B 38/10, 27.06.2005].

The shortcomings of this known prototype composition include insufficient compression strength, increased thermal conductivity, and low vapor transmission rate.

It is an object of the invention to achieve an increase in the compression strength, a decrease in the coefficient of thermal conductivity and an increase in the vapor permeability number.

The stated object is solved by the features of the claim.

The technical result is achieved in the following way:
The raw material mixture for autoclave foam concrete contains cement, sand, proteinaceous foaming agent and water. According to the invention, this mixture contains addition Sb-31 as a proteinaceous foam-producing agent, an additional additive NaF and the fine flour ash and slag residues from solid fuel combustion with a specific surface area S _sp. of at least 300 m ² / kg. The quantitative ratio is as follows (% by weight): cement 48.54 to 49.60 sand 5.82 to 6.23 foaming agent 0.34 to 0.36 above ash and slag residues 14.90 to 15.10 NaF additive 0.21 to 0.24 water 29.13 to 29.53

The registered totality of all these materials shows completely new properties of the mixture. It makes it possible to achieve the following new technical results, namely: improved thermal conductivity and vapor permeability and increased compression strength over the prior art and the prototype.

New is the application of the additive NaF and the flour fine ashes and slag residues (Table 1) of solid fuel combustion with S _sp. of at least 300 m ² / kg. This makes it possible to get a high technical result. If S _sp. is less than 300 m ² / kg, then the silicate activation of the ash and slag residues with the additive NaF will not increase. Consequently, the technical characteristics can not be achieved. The increase of the compression strength and the vapor permeability number and the reduction of the thermal conductivity are missing.

The chemical mineral content of ash and slag residues after solid fuel combustion is as follows (Table 1): TABLE 1 Ash analysis,% SiO ₂ Fe ₂ O ₃ Al ₂ O ₃ CaO MgO SO ₃ Na ₂ O ₃ K ₂ O 59.2 8.2 24.2 2.6 0.5 1.3 0.63 2.3

As a proteinaceous foam-producing agent, Sb-31 additive is used. This agent has a complicated composition: Table 2 description Wt .-%: Alkanes C12-C19 64 Isobutyl alcohol (isobutanol) 2 aliphatic amines C7-C9 (calculated by monoethanolamine) 21 formaldehyde 13

Addiment Sb-31 is a chemical foaming agent. It is prepared by the process of special conversion of the natural protein macromolecules by hydrolysis in water solution. The Sb-31 additive was specially developed for foam development. This foam is required in the production of porous lightweight concrete. He corresponds ASTM 869-80 ,

This composition of raw material mixture for autoclave foam concrete is unknown and new.

The above-mentioned technical result is achieved thanks to the use of very fine ash and slag residues of solid fuel combustion with the additive NaF. This additive contributes to increasing the hydration activity of the hardening system. The formation of an increased amount of tobermorite (5CaO · 6SiO ₂ · 9H ₂ O) water-rich calcium hydrosilicates occurs not only through chemical interaction with the cement, but also through the incorporation of the silicates into the hydration process. These silicates are part of the fine flour ash and slag residues. Thanks to the existing additive NaF a water structuring comes about. Hydrogen bonds of the F ^- anion are formed. Consequently, a simplified process of energy transfer arises from Hydrogen proton via the hydrogen bonding system. The degree of hydration of the silicate component of not only the Portland cement but also of the silicates belonging to the very fine ash and slag residues increases. This enhancement of the degree of hydration is achieved by a shift in the acid-base balance of the hardening system. This contributes accordingly to an increase in strength of the material produced.

The claimed invention is industrially applicable and can be used in the manufacture of autoclave-treated thermal insulation, construction and thermal insulation foam concrete. This concrete has improved properties in terms of thermal conductivity and vapor permeability and increased compression strength.

The feasibility of the invention will be confirmed by way of examples that demonstrate actual use.

Example 1:

• 1. Preparation of the raw material mortar mix for autoclave foam concrete: 1.1. The following are metered: Cement - PCM 400; Sand S _sp. = 200 m ² / kg; fine-grained ash and slag residues with S _sp. = 300 m ² / kg; NaF additive and water. 1.2. The dosed materials are conveyed into a foam concrete mixer. Here, the components are mixed to produce a homogeneous mortar mix.
• 2. Preparation of construction foam 2.1. It will be dosed: a concentrated solution of proteinaceous foam-forming agent Sb-31 and Add Water. 2.2. The dosed ingredients are mixed in a PE container until a homogeneous solution is achieved. The construction foam is made from this solution by means of a foam generator.
• 3. The prepared construction foam is conveyed by means of a pump of the foam generator in the concrete mixer. In this concrete mixer, a combined mixing with the prepared mortar mixture is achieved until a homogeneous foam concrete mass is formed.
• 4. The autoclave foam concrete mix produced is poured from the foam concrete mixer into the concrete molds using a gerotor pump to produce the required products and the test samples for inspection. The hardening of the products takes place in the autoclave in accordance with the procedural process.

Example 2:

• 1. Preparation of raw material mortar mix for autoclave foam concrete: 1.1. The following are metered: Cement -
  
  400; Sand S _sp. = 200 m ² / kg; fine-grained ash and slag residues with S _sp. > 300 m ² / kg; NaF additive and water. 1.2. The dosed materials are conveyed into the foam concrete mixer. Here, the components are mixed to produce a homogeneous mortar mix.
• 2. Preparation of construction foam 2.1. It will be dosed: a concentrated solution of proteinaceous foam-forming agent Sb-31 and Add Water. 2.2. The dosed ingredients are mixed in a PE container until a homogeneous solution is achieved. The construction foam is made from this solution by means of a foam generator.
• 3. The prepared construction foam is mixed with the prepared mortar mixture.
• 4. The manufactured raw material mixture is poured into molds. The hardening of the products takes place in an autoclave in accordance with the procedural process.

The researches of physico-chemical characteristics were carried out according to the requirements of GOST 12852-87 "Honeycomb concrete. General requirements for examination procedures ". These characteristics are included in Table 3.

The analysis of the experimental data shows that the notified raw material mixture for autoclave foam concrete, compared to the prototype, ensures the production of autoclave foam concrete with increased technical characteristics, namely: an increase of the compression strength by 12%; a reduction of the thermal conductivity by 10% and an increase of the vapor permeability by 10%. Table 3 Pos. No. Material consumption per 1 m ³ of foam concrete,% Mean density in dry condition, kg / m ³ Vapor Transmission Rate, μ = mg / m · hr · Pa Strength of foam concrete after 28 days, MPa, R _k . Cement PCM 400 PPOB * M-3 Addiment Sb-31 ** NaF *** water Sand S _sp. = 200 m ² / kg ZSO **** 1 prototype 40.4 9.2 - - 15.85 34,55 - 600 0.19 3.0 2 48.54 - 0.36 0.24 29.53 6,23 15.1 600 0.2 3.4 3 49.07 - 0.35 0.225 29.33 6,025 15.0 600 0.21 3.5 4 49.6 - 0.34 0.21 29.13 5.82 14.9 600 0.2 3.3 * Proteinaceous foam-producing agent modified by a complex modifier M-3;
** - Foaming additive Addiment Sb-31;
*** - chemical NaF additive;
**** - fine-grained ash and slag residues with S _sp. of ≥ 300 m ² / kg

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• RU 2145315 [0003]
• RU 2306300 [0005]
• RU 2255074 [0007]

Cited non-patent literature

• ASTM-869-80 [0016]

Claims (1)

Raw material mixture for Autoklavschaumbeton having cement, sand, proteinaceous foam-producing agent and water, characterized in that this raw material mixture Addiment Sb-31 as proteinaceous foam-producing agent, the additional additive NaF and fine flour ash and slag residues from solid fuel combustion with specific surface area S _sp of at least 300 m ² / kg and that this raw material mixture has a weight ratio in wt .-%: cement 48.54 to 49.60 sand 5.82 to 6.23 foaming agent 0.34 to 0.36 above ash and slag residues 14.90 to 15.10 NaF additive 0.21 to 0.24 water 29.13 to 29.53