RU2381193C1 - Additive for concrete mixture - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: invention refers to construction materials and can be used as additive for concretes and building mortars. Additive for concrete mixture includes the following, wt %: after-yeasty grains with content of dry matters - 4-5 wt %, pH - 5.0-6.0, density - 1.016 g/cm³ 94.00-96.10, sodium fluoride 0.45-0.50, potassium bichromate 0.45-0.50, calcium hydroxide 3.00-5.00.

EFFECT: improving strength at compression in early and design phase, decreasing water absorption and increasing cold resistance of concrete and building mortar.

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Description

The invention relates to the production of concrete of different densities and mortars and can be used in industrial and civil engineering, and for special purposes.

Known additive for concrete mix (RU No. 2058947, C04B 28/00, bull. No. 12 from 04/27/96), consisting of citrogypsum and calcium citrate filtrate.

The disadvantage of this technical solution is the low value of compressive strength at an early and design age, the increased value of water absorption and the low value of frost resistance.

Known additive for concrete mix, consisting of potassium chromate and magnesium compounds (SU No. 827440, C04B 28/02, from 07.05.81).

The disadvantage of this technical solution is the low value of compressive strength at an early and design age, the increased value of water absorption and the low value of frost resistance.

Closest to the claimed additive for concrete mixture is an additive (RU No. 2123482, C04B 28/00, dated 06/19/97) containing post-yeast distillery with a solids content of 3.5-4.5 wt.%, While the pH is 4, 5-5.5 and a density of 1.014 g / cm ³ , the modifier represented by the expanded porous product with a bulk density of 0.6 g / cm ³ is 3.0 ± 0.5 wt.%.

The disadvantage of this technical solution is the low value of compressive strength at an early and design age, the increased value of water absorption and the low value of frost resistance.

The objective of the invention is to create a new additive for concrete mix, the use of which would allow to achieve a technical result, consisting in increasing compressive strength at an early and design age, reducing water absorption and increasing frost resistance of concrete of different density or mortar.

This object is achieved in that the additive for concrete mix includes post-yeast distillery vinasse and a modifier represented by sodium fluoride, potassium dichromate and calcium hydroxide, and post-yeast vinasse has a density of 1.016 g / cm ³ , pH 5.0-6.0, and dry content substances - 4.0-5.0 wt.%, with the following weight ratio of components, wt.%:

Post-yeast Bard 94.00-96.10 Sodium fluoride 0.45-0.50 Potassium dichromate 0.45-0.50 Calcium hydroxide 3.00-5.00

A new, in comparison with the known additives in concrete, is the combination of the well-known post-yeast distillery stillage having a density of 1.016 g / cm ³ , pH of 5.0-6.0, dry matter content of 4.0-5.0 wt.%, with a modifier consisting of sodium fluoride, potassium dichromate and calcium hydroxide.

The use of potassium dichromate contributes to the oxidation of all forms of nitrogen in the filtrate to the nitrate form of nitrogen, which is practically absent in the initial filtrate, but its presence significantly enhances the activating effect of the filtrate; sodium fluoride mainly has a preservative effect, i.e. blocks the possible residual process of mass fermentation, which underlies the production of the main yeast product, the waste of which is the post-yeast vinasse, and at the same time additionally enhances the activating effect of the filtrate; calcium hydroxide has a stabilizing and additionally activating effect, because removes the PO ₄ ^-3 group from the filtrate, forming sparingly soluble compounds Ca ₃ (PO ₄ ) ₂ .

Thus, the filtrate of yeast production in the presence of the specified modifier has an effective activating effect, which allows to achieve the desired technical result.

At the filing date, according to the authors and the applicant, the claimed admixture in the concrete mixture is not known and this technical solution has world novelty.

The claimed combination of essential features exhibits a new property: increasing the strength of concrete at an early and design age, reducing water absorption and increasing frost resistance compared to the prototype.

It is another property of the aggregate that is not equal to the known properties of the distinguishing features that allows us to recognize this aggregate as compared with the new solutions known in science and technology, and the claimed invention corresponds to the eligibility criterion - inventive step.

The claimed invention is industrially applicable and can be used for the manufacture of additives for concrete mix.

Concrete example

1. Preparation of the additive

Dose:

- leachate filtrate having a density of 1.016 g / cm ³ , pH 5.5 ± 0.5, solids content of 4.5 ± 0.5 wt.%;

- sodium fluoride;

- potassium dichromate;

- calcium hydroxide.

The dosed components are transported to a mixer with a low-speed mixer, where mixing is carried out for 30 minutes and a ready-mixed concrete mix is obtained.

The finished product is transported in a vertical cone-shaped container equipped with a supply of compressed air for periodic bubbling of the additive, in order to prevent possible precipitation.

2. Preparation of concrete or mortar

Dose:

- additive in an amount of 1 wt.% by weight of cement;

- water;

- cement;

- sand;

- crushed stone.

The dosed additive is transported to the dosed mixing water and then all the dosed components are transported to the concrete mixer, where all components are thoroughly mixed; further preparation of the concrete mixture is carried out according to the technology adopted at the factory.

Evaluation of the effectiveness of the additive was carried out according to the parameters of compressive strength at an early and design age according to GOST 10180-90 “Concretes. Methods for determining the strength of control samples "; water absorption - according to GOST 12730.3-78 (1994) “Concretes. The method of determining water absorption "and the value of frost resistance - according to GOST 10060 (0-2) -95" Concretes. Methods for determining frost resistance. " The results obtained for concrete of class B22.5 with the following ratio: C: P: SC = 1: 2.13: 2.61 are presented in the table.

An analysis of the data shows that when using the inventive additive, the compressive strength at the age of 3 days increases by 71.9%, at the design age - by 43%, water absorption decreases by 27% and frost resistance increases by 3 times.

Claims (1)

Additive for concrete mixture, including post-yeast distillery vinasse and a modifier, characterized in that it contains sodium fluoride, potassium dichromate and calcium hydroxide as a modifier, and the post-yeast distillery distillate has a density of 1.016 g / cm ³ , pH 5-6, and solids content 4-5 wt.%, With the following weight ratio of components, wt.%:
Post-yeast Bard 94.00-96.10 Sodium fluoride 0.45-0.50 Potassium dichromate 0.45-0.50 Calcium hydroxide 3.00-5.00