SU1235845A1 - Method of preparing concrete mix based on large-size carbonate filler - Google Patents

Description

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This invention relates to the technology of obtaining construction products by molding them from a mixture of coarse and freshly filled water.

The aim of the invention is to improve the workability of the mixture.

The pretreatment of a large carbonate filler with an aqueous solution of acetic acid provides calcium acetate on its surface as a result of the chemical interaction between calcium carbonate and acetic acid. Calcium acetate contributes to a sharp increase in the workability of the concrete mix. In addition, calcium acetate, as a compound easily soluble, is easily removed from the surface of the carbonate aggregate during mixing and is distributed in a cement paste. In this case, a fresh filler surface is exposed, i.e. it is activated. This improves the adhesion of the cement paste (stone) to the aggregate. For this reason, with a dramatic improvement in the workability of the concrete mix on a carbonate aggregate treated with a solution of y:: acetic acid, the following was observed:

Example 1. To prepare a concrete mix. Take the following amount of components, kg / m:

Mobility cm

1.0

Compressive strength at 28 days old, MPa 35.0

As follows from the table. 1, when treating a carbonate aggregate with a solution of acetic acid, its concentration should be 1.2 1.2 1.3 mol / l.

O- 10

15

358452

Crushed stone limestone 1 fraction 10-20 mm 990 Sand 1.25-5.0 mm 310 Sand fr. About 14-1.25 mm 490 5 Cement390

Acetic acid solution.190

For testing, limestone crushed stone from the Kamensky deposit, Chernorechensky cement M400, sand from the Voznesensky deposit (river) with M 2.2 are used.

Lime crushed stone is pretreated with a solution of acetic acid.

- I

acids at a concentration of 1.2-10, 1.6-10, 1,310. To do this, coarse carbon & filler and acetic acid solution are simultaneously fed into the mixer (pan), mixed for 1.0 min. Then sand and cement are introduced into this mixture, mixed for another 2. 0 minutes until a homogeneous mass is obtained. The mobility of the concrete mixture is determined; samples of 10x10x10 cm are molded on a laboratory vibroplatform. After 28 days of wet curing, the specimens are tested on a hydraulic press. The test results are shown in Table. 1. For comparison, a concrete mixture was tested on a carbonate aggregate treated with a 30% aqueous solution of carbonic acid for 80 seconds.

Table 1

20

25

thirty

3: 5

3.0

5.0

9.0

31.5

34.0

33.0

Example 2. Concrete mixtures were prepared on a carbonate aggregate of the same composition as in Example 1. The carbonate aggregate of the 10-20 mm fraction was processed

a solution of acetic acid concentration 1,2 tO H 1,3-KG mol / l for 0.50, 1.0 and 1.5 minutes

The results of tests of concrete mixtures are given in Table. 2

Table

2.5 9.0

3.0 9.0

3.5 9.0

Editor N. Egorova

Compiled by I. Inozemtsev

Tehred O.Gortvay Proofreader S. Cherni

Order 3056/20 Circulation 640 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Paushska nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

.

35845-4

As follows from the table. 2, the processing time of carbonate rubble should be equal to 0.5-1.5 minutes.

The use of concrete mixes on a carbonate aggregate treated with a solution of acetic acid allows to significantly increase the mobility of the concrete mix while maintaining the strength of the concrete. This will lead to an improvement in the energy consumption for laying and compacting the concrete mix during molding and in general to abandon the molding equipment (injection molding method). If necessary, save

f5 workability can reduce water consumption, which will lead to an increase in concrete strength or (while maintaining strength) to a decrease in cement consumption.

Claims (1)

METHOD FOR PREPARING A LARGE CONCRETE MIXTURE FOR CARBONATE Aggregates by treating the latter with an aqueous acid solution and subsequent mixing with the cement and sand, characterized in that, in order to improve the workability of the mixture, carbonate filler treated with an aqueous solution of acetic acid concentration of 1.2 * "10 ^'e - 1.3 * 10 mol / L for 0.51.5 minutes. (L No. from 01 cl. T 23584 5