RU1835396C - Method for manufacturing of addition for cement-and-concrete mixture - Google Patents

Abstract

Usage: construction, production of additives for concrete mixture hardening at low temperature. SUMMARY OF THE INVENTION: a method of preparing an additive for a cement-concrete mixture, comprising treating aqueous condensate from washing the air of oxidizing columns of the production of synthetic fatty acids with sodium hydroxide or soda at a ratio of said aqueous condensate and Na (10-15): 1, respectively, at a temperature of 90-100 ° C for 1-2 m “In order to increase the plasticizing properties of the specified additive, an aqueous-alcoholic solution in an amount of 10-15% of its weight is distilled off. Concrete strength after 28 days of hardening at (-15) ° C -complies up to 32.8 MPa. 2 tab. w Ј

Description

The invention relates to the construction and production of building materials, in particular to methods for -; preparation of additives for concrete mixtures used in the manufacture of concrete and reinforced concrete products hardening at a negative temperature

A known method of preparing additives for cement concrete mixture is to process a mixture of organic acids - waste production of caustic soda about

The closest to the proposed technical essence and the achieved result is a method of preparing a complex additive for concrete mix by neutralizing with alkali at room temperature formic and acetic acids, which are waste products in the production of terpineol and containing sodium murevate and sodium acetate in the following ratio of components, wt.%:

Sodium formate 50 - 75 Sodium acetic acid 25 - 50.

I

This admixture does not allow concrete of sufficient strength at low temperatures.

00 GJ SL SO U O

The aim of the invention is to increase the strength of concrete at temperatures up to (15) ° C.

This goal is achieved by the fact that g as an aqueous solution of carboxylic acids use an aqueous condensate from washing air of oxidizing acids, which is treated with sodium hydroxide or soda at a ratio of K), respectively, the specified aqueous condensate and Na (): 1 at a temperature of 90-100 ° C for 1-2 hours

  In order to increase plasticize- jg

their properties from the specified additives are shed with a water-alcohol solution in the amount of 10-15 wt.% „

Composition of water condensate: Mura-20 sodium salts

Acidic acid 10 - T8 Sodium salts of acetic acid 7 12 Sodium salts of propionic acid 3 5 25 Sodium salts of butyric acid 1 3 Low molecular weight alcohols C, Water Else 30 :

pH 1.2-2.6.,

Acid number 180-2AO mg / KOH / g Ether number mg / KOH / g Mass fraction

dry residue 1,, 0% Q From the reaction product of the aqueous condensate with sodium hydroxide, Т0 of a 15% aqueous solution of low- is distilled off; of molecular alcohol by weight of the mixture by flash evaporation, 45

The method of preparation of the additive consists in loading water condensate into a flask with a mixing device and mixing mixture I

35

g)

g

0

fifty

Q 5

5

when heated for 1-2 hours, after which the mixture is cooled.

The concrete mixture using the proposed additives is prepared on Portland cement grade (OO with a flow rate of 350 kg / m3, sand MKr-2.1, granite gravel fr mm and water with a mass ratio of 1: 1,: 0.53.

The mobility of the concrete mixture is determined in accordance with GOST 10181-62, and the compressive strength of concrete is determined in accordance with GOST 10180-71 on samples of size stored before testing under isothermal conditions, Samples are maintained: at negative ambient temperatures, thawed before testing, in for hours in indoor conditions.

Table 1 presents the conditions for the preparation of the additive and the properties of concrete mixtures and concrete with its introduction, as well as data on the prototype and analogue

In the table. Figure 2 shows variations in the ratio of the components of the additive for examples 2-6 of the table. 1 o

Claims (2)

The claims 1 o A method for preparing an additive for a cement concrete mixture comprising. treatment with caustic soda or soda of an aqueous solution of carbolic acids, which, in order to increase the strength of concrete at a temperature of -15 ° C, as an aqueous solution of carboxylic acids, water condensate is used from washing the air of oxidizing columns producing synthetic fatty acids , while it is treated with sodium hydroxide or soda with a ratio of water condensate: 10-15: 1 at 90-100 ° C for 1-2 hours, " 2. The method according to claim 1, excellent. moreover, and in order to increase the plasticizing properties, an aqueous-alcoholic solution in an amount of 10-15% of it is distilled off from said additive. assu „ Table I The influence of the conditions for obtaining additives on the properties of concrete products made using the specified additives Test case   Table The ratio of the components of the water condensate in examples 2-6 4,5 +20 15 / 51.5 21.0 / 69.6 26.3 / 87, 30.1 / 100