RU2392252C1 - Raw mix for cellular concrete fabrication - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: raw mix for fabrication of cellular concrete includes the following components, wt %: portland cement 26.490 - 28.638, ground sand with specific surface S_sp. of at least 200 m²/kg 18.962 - 19.300, multi-layer carbon nanotubes with size of 10^-9 - 5.9·10^-8 m 0.001 - 0.002, ashes and slag waste from combustion of solid fuel with specific surface S_sp. of at least 300 m2/kg and content of SiO₂ of at least 55.0%, CaO of not more than 3.0 % 28.895 - 29.270, bentonite clay with specific surface S_sp. of at least 350 m²/kg 0.704 - 0.758, foaming agent 0.305 - 0.330, water 22.495 - 23.850.

EFFECT: improved thermal and sound protective properties of cellular concrete.

1 ex, 2 tbl

Description

The invention relates to the field of building materials and can be used for the manufacture of cellular concrete used in industrial and civil engineering.

Known raw material mixture containing, wt.%: Portland cement 43.0-46.2, slag of metallurgical production 12.0-14.4, sand 15.0-18.0, a foaming additive based on sodium stearate with a density of 1.15- 1.7 g / cm ³ 9.5-10.3, DEYA chemical additive 0.4-0.5, aluminum powder 0.5-0.6, fiber 1.4-1.8, water 12, 0-14.4 (RF patent No. 2145315, С04В 38/10, 03/02/1999).

The disadvantage of this technical solution is the reduced sound and heat-shielding properties of the material.

Known raw mix containing, wt.%: Portland cement 44.0-47.0, montmorillonite clay, comprising at least 60% of the mineral 11.0-13.8, foam-forming additive "NIKA" 0.5-0.7, water 40.0-42.8 (RF patent No. 2145586, С04В 38/10, 03/02/1999).

The disadvantages of this technical solution include the reduced sound and heat-shielding properties of the material.

The closest in technical essence to the claimed raw material mixture is a composition consisting of Portland cement, multilayer carbon nanotubes and water, containing, wt.%: Portland cement 33.0-77.0, multilayer carbon nanotubes in size (6.0 · 10 ^-8 ... 2.0 · 10 ^-7 ) m 0.0001-2.0, water - the rest (RF patent No. 2233254, С04В 28/02 // СВВ 111: 20).

The disadvantage of this technical solution is the reduced sound and heat-shielding properties of the material.

The problem to which the invention is directed, is the creation of cellular concrete with improved sound and heat-shielding properties.

The problem is achieved in that the raw material mixture for the manufacture of cellular concrete, including Portland cement, ground sand, multilayer carbon nanotubes, a foaming additive and water, contains ground sand with a specific surface area S _beats. not less than 200 m ² / kg, multilayer carbon nanotubes with a size of 10 ^-9 ... 5.94 · 10 ^-8 m and additional ash and slag waste from the combustion of solid fuels with a specific surface area S _beats. not less than 300 m ² / kg and SiO ₂ content _of not less than 55.0%, CaO not more than 3.0% and bentonite clay with a specific surface area S _beats. not less than 350 m ² / kg, with the following ratio of components, wt.%:

Portland cement 26,490-28,638 specified sand 18,962-19,300 specified ash and slag waste 28,895-29,270 indicated clay 0.704-0.758 specified nanotubes 0.001-0.002 foaming additive 0.305-0.330 water 22,495-23,850

New in comparison with the raw material mixture selected for the prototype is that ground sand is introduced with a specific surface - S _beats. not less than 200 m ² / kg, multilayer carbon nanotubes (MWCNTs) taken in the size of 10 ^-9 ... 5.9 · 10 ^-8 m and, in addition, ash and slag waste from burning solid fuel with a specific surface area - S _beats. not less than 300 m ² / kg with a content of SiO _{2 of} not less than 55.0% and CaO not more than 3.0%, bentonite clay with a specific surface - S _beats. not less than 350 m ² / kg.

According to the data of physical and chemical studies: X-ray phase and defirmational methods of analysis, it was found that in the presence of ash and slag waste from burning solid fuel with a specific surface area - S _beats. not less than 300 m ² / kg and a SiO ₂ content _of not less than 55.0%, CaO not more than 3.0%, and also in the presence of MWCNTs with sizes of 10 ^-9 ... 5.9 · 10 ^-8 m, an increased amount of calcium hydrosilicates is formed, represented mainly by low-basic calcium hydrosilicates type CSH (I) having a fibrous structure.

Table 1 Chemical and mineralogical composition of ash and slag waste from solid fuel combustion The chemical composition of the ash,% 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

The presence of bentonite clay in the composition of the raw material mixture has a positive effect on the formation of a stable structure of cellular concrete, which, in the presence of an increased amount of hydrated compounds, differs in the formation of small pores and, according to microscopic studies, small elongated pores open on one side are formed in the hardened foam concrete. All the above changes that occur during the hardening of cellular concrete (foam concrete) contribute to the improvement of sound and heat-shielding properties of the material.

At the time of application, according to the authors and the applicant, the inventive raw mix for the manufacture of cellular concrete is unknown and has a world novelty.

The inventive combination of essential features exhibits a new property of the raw mix for the manufacture of cellular concrete in the presence of ground sand with a specific surface - S _beats. not less than 200 m ² / kg, ash and slag waste from the combustion of solid fuels with a specific surface area - S _beats. not less than 300 m ² / kg and SiO ₂ content not less than 55.0%, CaO not more than 3.0%, bentonite clay with a specific surface - S _beats. not less than 350 m ² / kg, foaming additives and MWCNTs with a size of 10 ^-9 ... 5.9 · 10 ^-8 m, which allow to obtain improved heat and sound-proof properties of the material compared to the prototype.

The claimed invention is industrially applicable and can be used for the manufacture of heat-insulating structural concrete (foam concrete) with improved heat and sound-proofing properties.

Execution example

1. Preparation of mortar

1.1. Dose:

- Portland cement;

- ground sand with a specific surface - S _beats. not less than 200 m ² / kg;

- ash and slag waste from the combustion of solid fuels with a specific surface area - S _beats. not less than 300 m ² / kg and SiO ₂ content _of not less than 55.0%, CaO not more than 3.0%;

- bentonite clay with a specific surface - S _beats. not less than 350 m ² / kg;

- MWCNTs with a size of 10 ^-9 ... 5.9 · 10 ^-8 m;

- water.

1.2. Dosage materials are transported to a concrete mixer, where the components are mixed until a homogeneous mortar is obtained.

2. Preparation of construction foam

2.1. Dose:

- a concentrated solution of Addimen Sb-31 foam concentrate, which is a chemical foaming agent obtained by the special conversion process of natural protein macromolecules by hydrolysis in an aqueous solution, corresponding to ASTM 869-80, has a complex composition, wt.%: C ₁₂ -C alkanes ₁₉ - 64, isobutyl alcohol (isobutanol) - 2, aliphatic amines C ₇ -C ₉ (calculation according to monoethanolamine) - 21, formaldehyde - 13.

You can also use concentrated solutions of foam concentrates "NIKA" or "QUIN".

The raw materials used for the preparation of NIKA additives must satisfy the requirements established in the regulatory documents for these materials and meet the following characteristics: keratin-containing proteins: pH 6.5-7.0;

sulfuric acid according to GOST 2184-77; sodium alkali (caustic soda) according to GOST 2263-79; iron sulfate according to GOST 4148-78; sodium fluoride according to GOST 2871-75. The liquid is dark brown. Density not less than 1.026 kg / m ³ . The multiplicity of the foam is not less than 6. The stability of the foam is not less than 18 min (TU 5743-001-49990652-99).

The raw materials used for the preparation of KVIN additives must meet the requirements established in the regulatory documents for these materials and meet the following characteristics: sodium salts of higher fatty acids: pH 9.5-10.0, p = 1.005-1.01 g / cm ³ ; an aqueous solution of sodium silicate: pH 9.5-10.0, p = 1.010-1.012 g / cm ³ . The liquid is dark brown. The density is not less than 1.0-1.015 kg / m ³ . The multiplicity of the foam is not less than 6. The stability of the foam is not less than 12 minutes (TU 5743-001-49990652-99).

- water.

2.2. Dosage components are mixed in a polyethylene container until the solution is homogeneous.

2.3. Using a foam generator, building foam is obtained.

3. Preparation of the raw mix

3.1. Using the foam generator pump, the resulting construction foam is transported to a concrete mixer, where the prepared mortar and construction foam are mixed together to obtain a homogeneous raw material mixture of aerated concrete.

3.2. The obtained raw mix of aerated concrete from a foam mixer using a gerotor pump is poured into the form of the required products, the curing of which is carried out in accordance with the technological regulations.

Studies of physical and mechanical characteristics were carried out in accordance with the requirements of GOST 12852-87 “Cellular concrete. General requirements for test methods ”, GOST 16297-80 on sound permeability, GOST 7076-87 on thermal conductivity.

The results are presented in table 2.

Analysis of experimental data shows that the claimed raw material mixture for the manufacture of aerated concrete in comparison with the prototype provides aerated concrete with improved technical characteristics, namely: reducing sound permeability by 20%, lowering the thermal conductivity by 19%.

Claims (1)

The raw material mixture for the manufacture of aerated concrete, including Portland cement, ground sand, multilayer carbon nanotubes, a foaming additive and water, characterized in that it contains ground sand with a specific surface area S _beats. not less than 200 m ² / kg, multilayer carbon nanotubes 10 ^-9 ... 5.9 · 10 ^-8 m in size and, in addition, ash and slag waste from solid fuel combustion with a specific surface area S _beats. not less than 300 m ² / kg and SiO ₂ content _of not less than 55.0%, CaO not more than 3.0% and bentonite clay with a specific surface area S _beats. not less than 350 m ² / kg in the following ratio of components, wt.%:
Portland cement 26,490-28,638 specified sand 18,962-19,300 specified ash and slag waste 28,895-29,270 indicated clay 0.704-0.758 specified nanotubes 0.001-0.002 foaming additive 0.305-0.330 water 22,495-23,850