SU882964A1 - Foam generator for producing porous concrete mix - Google Patents

Description

one

The invention relates to the field of the manufacture of cutting materials. Gas formers are known for the porisation of a concrete mix, including aluminum powder and an additive (.1.

Their disadvantage is low activity.

Closest to the invention is a synthetic foaming agent 2 comprising surfactant (surfactant) - secondary alkyl sulfates, carboxymethyl cellulose and water. The composition of the blowing agent in terms of dry substances, May. %: secondary alkyl sulphates 0.62 Carboxymethylcellulose 0.13 Water 99.25

The disadvantages of this blowing agent are

a) the multiplicity of technical foam at elevated temperatures decreases due to the low surface activity of the used surfactant — secondary alkyl sulfates;

b) the durability of the foam concrete mixture at elevated temperatures decreases by 2-5% due to low concentrations of carboxymethyl cellulose in the foaming agent and second alkyl sulfates;

c) foam concrete mixtures based on the known blowing agent quickly thicken with increasing temperature, and their molding properties deteriorate sharply due to the chemical nature of the surfactant used and the low concentration of carboxymethyl cellulose;

g) the process of hardening of the foam during its heat treatment occurs

for a long time (from 14 to 18 hours), which is associated with the absence in the composition of the foaming agent used substances that accelerate the hardening of the concrete.

15 The purpose of the invention is to increase the multiplicity of technical foam and the durability of the concrete mix at elevated temperatures, to improve the molding properties of the hot foam concrete mix

20 acceleration of foam concrete hardening.

This goal is achieved by the fact that the foaming agent comprising a surfactant, carboxymethyl cellulose and water additionally contains potassium carbonate, and as a surfactant sodium alkyl benzene sulfonates based on kerosene or paraffins + IG H SOgNa, where n 10 g 18, in the following ratio

30 tov, may. %: Surface-active 0.4-2.67 substance Carboxymethylcellulose, 13-2.43 Potassium carbonate 0.67-4.9 Remaining For the preparation of the frother, three dosages of the components were prepared, May. % / g: Sodium alkyl benzene 0, 4 1.4 sulfonates on os30 110 nove kerosene or paraffins Carboxymethylcellulose, 13 1.28 2.43 lulose 10 100 200 0.67 2.56, 9 Potassium carbonate 50 200 400 98.8 94, 76 90 7400 7400 740 The indicated dosages of the components were mixed in a container for 5 minutes at and kept for 4 hours until a homogeneous mass was obtained. The effectiveness of the proposed foaming agent was determined as follows. 1. For each dosage of a frother with a volume of 1 ml, a technical foam was heated with a temperature of 5.30, 60, and 70 ° C and its multiplicity was determined (the ratio of the volume mass of the frother to the bulk weight of the foam. Foam was prepared by applying a frother in a mixer The temperature of the foam was increased by heating the water in the vessel, inside of which there was a mixer capacity, for 3 minutes. 2. The resistance of the foam concrete mixture was evaluated by the resistance coefficient, which was defined as the ratio of the volume of foam paste to the sum of equal volumes Foam and cement paste prior to their mixing. Foam was prepared by beating a 10 ml volume generator in a mixer for 3 minutes, foam temperature was 5, 30, 60 and 7 ° C. At the same time, a cement test was prepared with a total substitution ratio of 0.4 and with a temperature of 5.30, 60 and by manually mixing for 3 m of cement and water, previously heated (or cooled) to a given temperature, the volume of cement paste in each experiment was equal to the volume of foam. SfexeM foam and cement paste were mixed in a mixer for 3 minutes, the volume of the foam-cement paste was determined and the coefficient of persistence was calculated. 3. The molding properties of the hot foam concrete mixture were evaluated by the amount of precipitation of the cone from the foam mixture. For this, foam concrete mixes with a temperature of 20 and 60 s were prepared in the mixer for 3 minutes. The cost of materials per batch was as follows: cement grade 400 2 kg, silica sand 6 kg, frother 0.74 kg, water 1.0 kg. Then, the foam concrete mixture was placed in a standard cone with the dimensions: bottom diameter 1000 mm, upper diameter 70 mm, height 60 mm, and sealed with a bayonet, the cone was removed, and the diameter of the foam concrete mixture was measured. 4. Samples of 160 X 40 X 40 mm were molded from these mixtures, the samples were hardened in a steam chamber for 6.5-10 hours, then some samples (9 pcs. Each) were tested for flexural strength and compression, and another (9 pcs.) was kept for 28 days at 20 + 2 ° С and relative humidity of air 95 + 5%, and then tested for strength under bending and compression. Acceleration of foam concrete hardening was estimated by the strength of steamed samples as a percentage of the strength of 28 daily samples. For comparison, similar tests were carried out for each known foam former, g / may. %: Secondary alkyl sulfates 25 / 0.62 Carboxymethylcellulose 5 / 0.13 Water4000 / 99.25 The results of the tests performed are summarized in table. 1 and 2. It can be seen from the above data that the proposed frother for the production of foam concrete, in comparison with the known, allows to increase the foam multiplicity at elevated temperatures by 1.2-1.4 times, to increase the resistance of the foam concrete mixture to 1.05-1 , 15 times, to improve the molding properties by 1.08-1.25 times and speed up the process of curing foam concrete by 1.1-1 | 35 times. The expected effect of admixing the foaming agent, as compared with the known, is as follows: 1. The technical foam increases at elevated temperatures by 22-37%, which allows reducing the foaming agent consumption by 1 m of the foam concrete mixture by 10-20 liters, the cost of 1 m of foam concrete due to this, it decreases by 0.1-0.2 rubles, 2. The cost of the foam concrete mixture at elevated temperatures increases by 5-14%, thereby improving the structure of the foam concrete and increasing its durability. 3. The molding properties of the hot foam concrete mixture are improved, the cone slump is reduced by 8–25%, which reduces the water content of the hot mixture while maintaining the desired flexibility of the mixture, while improving the quality of the products.

4. The duration of heat treatment of foam concrete is reduced by 10-35%, which allows reducing the consumption of thermal energy by 15-40% and increasing the output

products by 5-15%. The reduction in the cost of production of 1 m of foam concrete products is 0.81.7 rubles.

Table 1

Known Secondary alkyl sulfonates 0.62; Carboxymethylcellulose 0.13; Water 99.253.0 4.6 Suppliers: frother, Sodium alkyl benzene sulfonates based on kerosene or paraffins 0.4; carboxymethylcellulose 0.13, potassium carbonate 0.67, water 98.83.6 4.5

Sodium alkyl benzene sulphonates based on kerosene or paraffins 1.4; carboxymethylcellulose 1.28; potassium carbonate 2.56; water 94,763,0

Sodium alkylenesol sulfonates based on kerosene or paraffins 2.67; carboxymethylcellulose 2.43; potassium carbonate 4.9; water 90,02,5

Prototype

Secondary alkyl sulfates 0.62; carboxymethylcellulose 0.13; water 99,25 Proposed frother

Sodium alkyl benzene sulphonates based on kerosene or paraffins 0.4; carboxymethylcellulose 0.13, potassium carbonate 0.67; water 98,8

0.92 0.95 0.96 0.95

0.94 0.96 0.97 0.97

10.0 2.5 19.5 5.0 30.5 7.6

16.0 3.9 24.0 6.1 30.6 7.7 0.91 0.91 0.87 0.85 4.5 4.0 0.9 0.91 0.92 0.92 5, 5 5.3

Claims (2)

Sodium alkyl benzene sulphonates based on kerosene or paraffins 1.4; carboxymethyl cellulose Jf28, potassium carbonate 2.56; water 94.76 Sodium alkyl benzene sulphate based on kerosene or paraffins 2.67 / carboxymethylcellulose and 2.43; carbon dioxide 4.9; water 90.0 Claims of the invention Foaming agent for porous concrete mixture, including surfactant, carboxymethylcellulose and water, characterized in that, in order to increase the multiplicity of technical foam and resistance of the foam concrete mixture at elevated temperatures, improve the molding properties of hot foam concrete mixture and speed hardening of foam concrete; it contains sodium alkyl benzene sulfonates based on kerosene or paraffins as a surfactant, where n 10-g 18, and additionally potassium carbonate in the following ratio onentov, May. %: Continued table. 2 19.6 5.2 29.6 7.2 33.0 7.9 18.0 4.8 26.8 6.8 31.0 7.6 Surfactant0.4-2.67 Carboxymethylcellulose0, 13-2.43 Potassium carbonate 0.67-4.9 WaterErestary Sources of information accepted into account in the examination 1. The author's certificate of the USSR 376337, cl. From 04 To 15/02, 1971. 2. Instructions for the manufacture and use of wall panels and blocks, of expanded clay foam concrete for livestock and poultry buildings of veins 0.3-77, M., ONTI, TsNIIEPselostroy, 1977, p. 20.