RU2493124C1 - Masonry mixture - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: masonry mixture is intended for production of mortars, for binding elements of different masonries (bricks, natural stone, concrete blocks). Masonry mixture includes Portland cement - 14-17%, slaked lime - 3-5%, quartz sand - 75.24-81.28%, calcium stearate - 0.11-0.13%, sodium oleate - 0.11-0.13%, red sludge - 1.5-4.5%.

EFFECT: inclusion of alumina production waste - red sludge - in production of dry building mixtures, which makes it possible to vacate territories, occupied with sludge fields, with improvement of all indicators of ready masonry mortar.

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Description

The invention relates to the production of building materials. The mixture is intended for the preparation of solutions for connecting elements of various masonry (brick, natural stone, concrete blocks).

Cement, cement-lime and cement-clay mortars are most often used for masonry [1]. Cement-lime mortars usually include Portland cement, lime and quartz sand in various proportions, depending on the purpose, in combination with a small amount of organic additives [2]. Such a composition was chosen as a prototype. Weaknesses of masonry mortars are low strength, unacceptable deformation during hardening, poor water-holding ability, low adhesion to masonry, etc.

The objective of the invention is the creation of a dry cement-lime masonry mixture using as an additive waste production of alumina - red mud - while maintaining or improving all indicators of the finished masonry mortar.

The problem is solved in that in the composition of the masonry mixture, including Portland cement, slaked lime, quartz sand and organic additives, according to the claimed solution, calcium stearate and sodium oleate are taken as organic additives, and crushed red mud with a specific surface area of at least 12000 is also added cm ² / g, a residual moisture content of not more than 2% and a water-soluble alkali content of not more than 0.6% with the following content of all components,% wt .:

Portland cement - 14-17,

slaked lime - 3-5,

quartz sand - 75.24-81.28,

calcium stearate - 0.11-0.13,

sodium oleate - 0.11-0.13,

red mud - 1.5-4.5.

Extensive experimental studies have made it possible to determine both the possibility of achieving this task and the permissible limits of the content of red mud in the composition of masonry mixtures. It has been experimentally established that red mud is best introduced into the composition in an amount of 1.5-4.5%.

Red mud has a complex composition with an Al ₂ O ₃ content of at least 10%, Fe ₂ O ₃ at least 50%, Na ₂ O at no more than 5%, TiO _{2 at} up to 7%, CaO at up to 8%, SiO ₂ - up to 6% and cannot be considered an equivalent replacement for any of the other components of the masonry mixture.

In the course of the experiments, it was also found that only finely ground red mud with a specific surface area of at least 12,000 cm ² / g, a residual moisture content of not more than 2%, and a water-soluble alkali content of not more than 0.6% are suitable for preparing solutions of acceptable quality.

Red mud was introduced in the following amounts:

- control - 0%,

- option 1 - 1.5%,

- option 2 - 4.5%,

- option 3 - 2.5%.

The table shows the results of test tests of solutions prepared from masonry mixtures. The determination of the relative linear strains was carried out on samples 40 × 40 × 160 mm in size at a temperature of 20 ± 2 ° С. The table shows that the addition of red mud reduces the kinetics of the development of deformations during hardening, however, in general, after 28 days, the deformations turn out to be close in all cases and do not go beyond the recommended limit for masonry mortars: 1.20 mm / m. It is clearly seen that the inclusion of red mud in the composition of the mixtures significantly increases the strength characteristics: if the bending strength increases insignificantly, it increases by 1.5-2 times during compression, and the adhesion to the base increases almost threefold. Also, water-holding ability is noticeably growing.

Analysis of the results allows us to conclude that option 1 and option 2,3 significantly improve the quality of the masonry mixture. Higher red mud content showed worse results. Therefore, it is logical to designate the optimal range of red mud content as 1.5-4.5%.

The technical result of the invention is the involvement of waste from the production of alumina - red mud - in the manufacture of dry building mixtures, which allows you to free occupied by sludge fields and reduces the cost of the finished product.

Information sources

1. V.G. Mikulsky and others. Building materials. Textbook ed. // M., Publishing house of the association of construction universities, 2004, p. 308.

2. E.G. Muradov. Materials for the preparation of concrete mix and mortar // M. "Higher School", 1987, p.100.

Table 1 Masonry mix No. of examples The starting components,% wt. Portland cement Slaked lime Calcium stearate Sodium stearate Red mud Quartz sand one 14.0 3.0 0.11 0.11 1,5 81.28 2 15.0 4.0 0.13 0.11 4,5 76.26 3 17.0 5,0 0.13 0.13 2,5 75.24 four 13.0 3.0 0.10 0.10 1,0 82.80 5 18.0 6.0 0.20 0.20 5,0 70.60 Prototype 17.0 5,0 0.11 0.11 0 77.78 No. of examples The properties Water retention capacity,% Bending strength after 28 days, MPa Compressive strength, MPa, in a day The strength of adhesion to the base after 28 days, MPa Linear deformation, mm / m, in a day 3 7 28 one 7 fourteen twenty 23 28 one 80.3 2.9 4.7 9,4 13.8 0.30 0.06 0.18 -0.23 -0.84 -0.91 -0.94 2 82,2 2.6 4,5 9.3 12.9 0.29 0.08 0.20 -0.18 -0.80 -0.89 -0.91 3 82,4 2,4 4.4 9.3 11.2 0.28 0.18 0.28 -0.16 -0.78 -0.86 -0.90 four 79.0 2.2 3.8 6.6 9.9 0.25 0.01 0.00 -0.25 -0.88 -0.94 -0.94 5 78.1 2,3 4.0 7.1 10,2 0.27 0.04 -0.07 -0.28 -0.92 -0.99 -1.03 Prototype 77.5 2.1 1,2 3.0 7.2 0.11 -0.01 -0.06 -0.51 -0.87 -0.99 -1.00

Claims (1)

A masonry mixture including Portland cement, slaked lime, silica sand and organic additives, characterized in that calcium stearate and sodium oleate are taken as organic additives, and crushed red mud is also added with a specific surface area of at least 12,000 cm ² / g, residual moisture not more than 2% and a water-soluble alkali content of not more than 0.6% with the following content of all components, wt.%:
Portland cement 14-17 slaked lime 3-5 quartz sand 75.24-81.28 calcium stearate 0.11-0.13 sodium oleate 0.11-0.13 red mud 1,5-4,5