SU876587A1 - Method of preparing concrete mix - Google Patents

Description

(54) METHOD FOR PREPARING A CONCRETE MIXTURE

The invention relates to the production of concrete mixtures, in particular to the preparation of concrete mixtures with additives. A known method for preparing concrete cm s consists in mixing cement, aggregate, additives (phenol, cresol, naphthol) and water 1. The closest to the proposed method to the technical essence and the achieved result is a method for preparing a concrete mix, including mixing cement and aggregate with the subsequent introduction of the by-product of the distillation of raw benzene with the mixing water. The purpose of the invention is to increase the strength of the concrete. This goal is achieved by the fact that in the method of preparing a concrete mix, which includes a cement and filler mix, followed by the introduction of the additive water by-product, rectification of the raw benzene with the mixing water, introduces the alkaline waters of the raw benzene rectification In an amount of 0.1 - 0, 5% by weight of cement in terms of dehydrated product. At the coke-chemical plants in the benzene distillation workshops, after the benzene-toluene-xylene fraction is purified from the sulphate treatment of the benzene fraction, alkaline waters of the benzene rectification are formed. In the process of washing, the benzene-toluene xylene fraction with an aqueous solution of sodium hydroxide, the sulfonic acid formed after the sulfate purification, as well as esters, excess sulfuric acid and hydrogen sulfide impurities are neutralized with alkali to form salts. Therefore, the alkaline waters of benzene rectification include sodium salts of acid esters and sulfonic acids, sodium sulfate and sulfide, excess alkali and pyridine. If the alkaline waters of benzene distillation contain 77.65% water, sodium sulfate () is 7.44%, a mixture of salts of acid esters corresponding to the general formula; Ro-5-Ma or RSQijNa is 7.46%; a mixture of salts of organic sulfonic acids, sulfobenzene .Na sulfotoluene CH CH SOgNa, and sulphoxyl acid — (CHafy CH SOtNa 6.63%; pyrvdine C H N 0.03%; sodium hydroxide NaOH, 0.7%; sodium sulfide, 0.12%. If the alkaline waters of benzene distillation contain more or less water, the percentage of salts and pyridine increase or decrease, respectively. Sulfosalt, which is part of alkaline waters, are surface-active they retain these properties during the preparation of This property of surfactants is essential for complex chemical additives in concrete. In addition, sodium sulfate, which increases their efficiency, is included in alkaline water rectification of benzene, since after washing the fraction of benzene-toluene-xylene, alkaline waters are then subjected to additional evaporation in order to completely recover benzene, toluene and xiool, the concentration of salts and pyridine in alkaline waters increases in the process of evaporation, since not only benzene but also water evaporates. . By complete evaporation of water in coke-chemical plants, a mixture of salts and pyridine can be obtained in a dry water. Making a mixture of dry salts from alkaline waters of benzene rectification by the complete evaporation of water is more rational, since in this type the process will be more transportable and its

no chemical indicators

Compressive strength after steaming, kgf / cm

The mobility of the concrete mix, cm

Water / cement ratio

Test results for sample cubes

with additives

prepared

SHVRB acid tar

0.5% of

17.4

0.1% of

g weight tsevesa price ment ment

272

246

100

3

3 0.40

3 0.50

0.42 MUST be added directly to cement in cement plants. The use of alkaline waters of benzene rectification as a complex chemical additive in the concrete mix will allow utilizing this waste. For tests of alkaline waters of benzene rectification, Portland cement 400 is used as a complex chemical additive, crushed granite fraction 20–40 mm with a strength of 800–900 kg / cm, sand with a particle size module of 1.6. With the same material consumption, three concrete mixes are made. The prepared acidic tars are added to the concrete of the calculations; 13.4 kg per 1 m of concrete and 17.4 kg per 1 m of concrete. Alkaline waters of benzene rectification (SCHRB) are added to concrete at the rate of 0.1% and 0.5% by weight of cement, calculated on the dry matter. In addition, cubic samples are prepared without chemical additives (control) When adding prepared acidic resin, the water-cement ratio is 0.52 and 0.5, depending on the dose of the additive, and 0.42 and 0.4, respectively, for addition of the URBRB. Without chemical additives, the water / cement ratio is 0.55. Thus, when adding SHVRB, the volume of water used to prepare the concrete mix is reduced by 17–22%, while the mobility of the concrete mix does not differ from the mobility of the concrete mix without chemical additives. Such a significant decrease in water contributes to an increase in concrete strength. The table shows the chemical indices of the sample cubes.

5876587 6

Claims (1)

1. Patent of Germany N 1228543, cl. From 04 To 13/24,