RU2256632C1 - Autoclave ash foamed concrete - Google Patents

Abstract

FIELD: manufacture of building materials; manufacture of articles for industrial and civil engineering.

SUBSTANCE: proposed autoclave foamed concrete contains cement, lime, filler, water and foaming agent in form of sand and ash after burning sediment of waste water at the following relationship of components, mass-%: cement, 28.7-33.5; lime, 4.6-7.6; sand, 17.5-18.1; ash, 17.5-18.1; foaming agent, 0.32-0.33 and water, 26.57-27.18. Proposed concrete absorbs ions of heavy metals and makes it possible to utilize industrial wastes.

EFFECT: improved protective properties of concrete; enhanced ecological safety; facilitated procedure.

1 tbl, 1 ex

Description

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

Known heat-insulating concrete containing, by weight. %: cement - 44.0-47.00; “NIKA” foaming additive (based on hydrolyzed blood of cattle, where aluminum sulfate Al ₃ (SO ₄ ) _{3 was} used as a stabilizer) - 0.5-0.7, montmorillonite clay (including at least 60% of the mineral (Al, Mg) ₂ (OH) ₂ [Si ₄ O ₁₀ ] · H ₂ O and with a specific surface of 1500-2000 cm ² / g) - 11.0-13.8 and water - 40.0-42.8 (RF patent No. 2145586 C 04 B 38/10, 03/02/1999).

Known heat-insulating concrete, containing, wt.%: Cement - 43,0-46,2; finely ground slag of metallurgical production (with an Fe (II) content of not more than 4%) - 12.0-14.4; sand - 18.0-15.0; a foaming additive (based on sodium stearate of a density of 1.15-1.7 g / cm ³ ) - 9.5-10.3; DEYA chemical additive (includes post-yeast distillery vinasse and modifier - expanded porous product with a bulk density of 0.5 g / cm ³ in an amount, wt.% 3.0 ± 0.5, represented by calcium-magnesium silicates) - 0.4- 0.5; aluminum powder - 0.5-0.6; fiber - 1.4-1.8 and water - 12.0-14.4 (RF patent No. 2145315 C 04 B 38/10, 02.03.1999).

Closest to the claimed mixture selected for the prototype, is a mixture for cellular autoclaved foam concrete containing cement - 38.0-42.0; sand - 28.0-30.0; lime - 4.2-4.6; complex foaming additive (sodium abietate C ₁₉ H ₂₉ COONa · 3C ₁₅ H ₂₉ COOH - 30.30-33.67; potassium alkali KOH - 6.88-7.64; glue - 10.67-11.83; water - 34.11-37.86 and salts of fatty acids - 9.0-18.0) - 0.4-0.7 and water - 25.4-26.7 (RF patent No. 2205814 C 04 V 38/10 , 05/06/2002).

The disadvantages of these analogues and prototype include insufficient thermal insulation properties of the material (increased coefficient of thermal conductivity) and low environmental protection properties (in terms of protection against heavy metal ions).

The objective of the invention is the creation of a new mixture that provides autoclaved ash concrete with improved protective properties in thermal insulation and environmental performance, by improving the ability of the material to adsorb heavy metal ions.

The problem is solved in that this autoclaved ash foam, including cement, lime, aggregate, water, a foaming additive, as a filler it contains sand and ash from burning sewage sludge, in the following ratio of components, wt.%:

cement 28.7-33.5

lime 4.6-7.6

sand 17.5-18.1

ash 17.5-18.1

foaming additive 0.32-0.33

water 26.57-27.18

At the time of application, according to the authors and the applicant, the inventive mixture for autoclaved ash-concrete is not known and has a world novelty.

The claimed combination of essential features exhibits a new property that allows you to obtain the specified technical result, namely: the thermal insulation properties of the material are improved (thermal conductivity decreases) and the ability to adsorb heavy metal ions with equal other physical and mechanical properties is improved in comparison with the known technical solutions.

The prior art is the use of ash from the combustion of sewage sludge for the production of heavy concrete, light concrete and in ceramics (ceramic brick production). The indicated technical result is obtained due to a new combination of components, which are cured under hydrothermal conditions at a temperature of 175 ° C and at a pressure of 8 atm. and provide a tobermorite binder in a gel state, which gives the resulting foam concrete a lower value of the coefficient of thermal conductivity and increased protective ability for heavy metal ions.

The claimed invention is industrially applicable and can be used in industrial and civil engineering for the manufacture of products characterized by improved thermal conductivity and environmental protection.

In addition, the use of ash from the burning of sewage sludge as a filler for the manufacture of autoclaved ash foam will allow the utilization of ash from the burning of sewage sludge, expand the raw material base of construction, and simplify the technology for the production of autoclaved foam concrete.

The feasibility of the invention is confirmed by examples of specific performance.

An example of a specific implementation.

Production of autoclaved ash-foam concrete.

1. Dose cement using a dispenser.

2. Dose lime using a dispenser.

3. The sand is crushed by a continuous wet mill to a specific surface S _beats. ≈ 200 m ² kg.

4. Dose the sand slurry using a dispenser.

5. Dose the ash (specific surface S _beats ≈ 200-3 00 m ² / kg) using a batcher.

6. Dose water through a flow meter into a sand grinding mill, into a tank for preparing a working solution of a foaming additive, into a weight batcher in front of the mixer.

7. Prepare a foaming additive (“NEOPOR” - oligopeptides and protein hydrolysates with pH = 6-8) from a foam concentrate (Makhambetova UK, Soltambekov TK, Estemesov ZA “Modern foam concrete”, St. Petersburg, 1997):

7.1. dosing the resulting foaming additive;

7.2. the metered foaming additive is mixed with water in a 1:25 combination to form a working solution of the foaming additive.

7.3. the resulting working solution of the foaming additive with the help of a foam generator is converted into foam with a bulk density of 80 g / l.

8. Dosed slurry of sand and ash, water, cement, lime enter the mixer, where mixing is carried out for 2 minutes.

9. To the prepared mortar mixture add the resulting foam and mix thoroughly for 1 minute until a homogeneous foam concrete mixture is obtained.

10. The resulting foam concrete mixture is used for the preparation of products and samples that are autoclaved:

10.1. pre-aged in pre-exposure chambers with t = 30-40 ° C for 4-6 hours;

10.2. hardening of concrete in an autoclave according to the scheme 2.5-12-4 (hours), where 2.5 hours is the temperature rise from 20 ° C to 175 ° C; 12 hours - isothermal heating at t = 175 ° C and pressure p = 8 atm .; 4 hours - cooling at normal pressure.

11. Foam concrete samples after autoclaving are subjected to tests in accordance with the requirements of TU 5741-004-51556791-2002 “Small wall blocks made of cellular concrete (foam concrete)”. Autoclaved ash foam test results are presented in the table.

An analysis of the results shows that autoclaved ash-foam based on the proposed composition is characterized by reduced thermal conductivity and improved environmental performance due to improved ability of the material to adsorb heavy metal ions.

This material can be recommended for the manufacture of products characterized by improved thermal conductivity and environmental protection for housing and civil engineering.

Claims (1)

Autoclaved ash-foam, including cement, lime, aggregate, water, a foaming additive, characterized in that it contains sand and ash as a filler from burning sewage sludge, in the following ratio, wt.%: Cement 28.7 - 33.5 Lime 4.6 - 7.6 Sand 17.5 - 18.1 Indicated ash 17.5 - 18.1 Foaming additive 0.32 - 0.33 Water 26.57 - 27.18