SU1399296A1 - Method of preparing concrete mix - Google Patents

Abstract

The invention relates to methods for preparing a concrete mix and may find application in the construction materials industry. The aim of the invention is to increase the water resistance and reduce the corrosion of concrete. The method is carried out as follows. The filler is mixed with dement and finely dispersed calcium carbonate, taken in an amount of 5-15% by weight of cement, after which the mixture is treated with a solution of hydrochloric acid in an amount of 1-2% by weight of cement. The water resistance of concrete is 8-10 atm, the corrosion rate of reinforcement in concrete is 0.0008 - 0.0014 mm / year. 1 tab. and S cl

Description

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The invention relates to methods for preparing a concrete mix and may find application in the manufacture of building materials.

The purpose of the invention is to waterproof the concrete and reduce corrosion of the reinforcement.

Raw materials: Belgorodsky Portland cement, carbonate crushed stone of fractions 5-10 and 10-20 mm, river quartz sand with Mk 1.89, finely dispersed calcium carbonate — screenings of carbonate rubble and sand with a particle size of less than 0.15 mm, hydrochloric acid.

Example 1. The ratio of cement; sand: crushed stone (c: p: u) equals 1: 1: 2.2, w / c 0.39.

The preparation of the concrete mix is carried out in the following sequence. Aggregates, cement and finely dispersed calcium carbonate are mixed in quantities of 5% by weight of cement, after which the mixture is treated with an aqueous solution of hydrochloric acid in an amount of 1% by weight of cement for 30 seconds, then water is added.

In the same way, the mixture is prepared according to examples 2, 3 and 4. The ratios of the main components and the amount of the additives added according to examples 1-4 are tabulated.

the concrete mix is placed in molds and compacted by vibration.

For watertight testing, they CRAFT sample cylinders with a diameter and height of 15 cm, and for

Determination of corrosion of reinforcement samples - cubes 10x10x10 cm.

Corrosion of the reinforcement is determined on polished steel samples with a length and diameter of 8 mm, which are placed in concrete samples and held at a relative humidity of over 90% and a temperature of 20 ° C. The corrosion rate of the reinforcement was determined by the mass loss over a specified period of time. The test results are shown in the table.

When testing concrete received

according to the prototype method under similar conditions, the water resistance is 5 atm, the corrosion rate of reinforcement in concrete after 6 months is 0.0090 mm / year,

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So when using

The proposed method increases the water resistance of concrete by 2 times, and the corrosion rate of reinforcement decreases 4-10 times.

Claims (1)

Invention Formula The method of preparing a concrete mix by mixing cement, water and a filler treated with hydrochloric acid in the amount of 1-2% of the cement mass is excellent so that, in order to increase the water tightness and reduce corrosion of the reinforcement, the aggregate is before processing mixed with cement and fine calcium carbonate in the amount of 5-15% by weight of cement.