RU2620666C2 - Mortar - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to mortar compositions and can be used for finishing, plastering and masonry works. The mortar contains a mineral binder, sand, additives and water. The mortar is a product of joint grinding of mineral binder, sand fraction below 5 mm and a mineral additive to the specific surface - 400-450 m²/kg. The mineral binder is cement clinker and lime flour, and the mineral additive is the mixture of tylose, vinnapas, PAA grade. Praestol flocculant, in the following ratio, wt %: cement clinker 50, sand 34-36, limestone flour (calcite) - 13-15, PAA - 0.1 tylose - 0.2 vinnopas 0.05-0.2, water - to obtain the desired mobility.

EFFECT: invention provides a mortar, which reduces shrinkage, peelability, increases strength and water retention, improves adhesion.

1 ex

Description

The invention relates to compositions of building mixtures and can be used to perform finishing, plastering and masonry work.

Building mixtures are known, including astringent inorganic substances, fine aggregates, additives and water (Chekhov A.P. et al. Concrete and mortar reference materials. Kiev, Budivelnyk, 1983, p. 183).

A building mixture is also known, including the product of co-grinding cement clinker, sand, gypsum stone, mineral additives and water (Butt Yu.M. et al. Technology of binders, Moscow, 1965, pp. 593, 598, 599).

The disadvantage of this building mixture is the presence of shrinkage deformations.

The closest in technological essence and the achieved effect is a building mixture containing a joint grinding product of a mineral binder, sand fraction less than 2.6 mm and a mineral additive to a specific surface of 350-400 m ² / kg in ratios, in particular: cement clinker - 1, sand - 2, gypsum stone 2 ÷ 3.6% by weight of cement binder, expanded vermiculite - 1 ÷ 2% by weight of cement binder, water - until the specified mobility is obtained (Belan V.I. et al. Building mixture patent RU 97116768 A, IPC S041 B38 / 08).

The task to be solved is to obtain a building mixture with the necessary strength and mobility for finishing, plastering and masonry work with a significant reduction in shrinkage deformation.

The problem is solved due to the fact that the building mixture contains the product of co-grinding cement clinker, limestone powder and sand of polymer additives to a specific surface of 350 ÷ 400 m ² / kg, and polyacrylamide (PAA), Tylose and Vinnopas are used as polymer additives, the following ratio of components:

Cement clinker - 50% by weight

Sand - 34% -36%

Calcite (limestone flour) - 13% -15%

PAA - 0.1%

Tylose - 0.2%

Vinopas - 0.05 ÷ 0.2%

Water - until a given mobility is obtained.

The use of PAA brand flocculant Praestol, manufactured in Perm, can improve the strength characteristics of the mixture. Flocculants like Praestol (PAA) produce:

- Neogenic - by polymerization of acrylamide;

- cationic - by copolymerization of acrylamide and a cationic comonomer based on acrylic acid (for example, sodium acrylate).

Physico-chemical indicators of flocculants are as follows:

- Appearance - white or yellowish loose powder;

- particle size distribution,% granules larger than 1250 microns in size - not more than 10%;

- flowability, g / s - not less than - 1.5;

- bulk density - 550-700 g / cm ³ .

Tilosa finds the main use in building mixtures and paints. The initial use of Tylose in construction mixtures as a water-retaining agent has now become much wider. Thanks to special modifications of the polymer structure and auxiliary additives, Tylose has a great influence on almost all the basic properties of building mixtures. Tylose is cellulose ethers; methylhydroxyethyl cellulose is used for use in building mixtures.

Vinnapas RE 523 Z dispersible powder was used. This rheologically neutral dispersible powder is used for the manufacture of a new generation of self-leveling floors and in wall products. Dispersible powders are dispersions dried by spray drying. When mixed in water, they again form a stable dispersion, the characteristics of which are comparable to the characteristics of the initial dispersion. The dispersible powder additive acts in three ways: it increases the ability of the solution to retain water through the formation of a film, reduces its evaporation and, finally, it strengthens the solution as an additional binder.

The introduction of a certain fraction of sand into the composition of the construction mixture, as a mineral binder - cement clinker, limestone flour, as polymer additives - a mixture of PAA, Tylose, Vinnopas in the indicated quantities and their joint grinding to 350 ÷ 400 m ² / kg allows to obtain a more uniform a building mixture of a given mobility, which is applied to the surface with a thinner and more even layer and when dried, practically does not shrink and displace when facing decorative materials.

Grinding the components to the specified specific surface, on the one hand, allows you to get the strength and mobility necessary for finishing, plastering or masonry work, and on the other hand, not to increase more energy consumption to obtain a technical result.

The amount of cement clinker is selected from the ratio of ensuring the strength of building mixtures.

Calcite (limestone powder) provides a better setting of the mortar and its water-holding ability. The amount of it is selected from the preservation of the necessary setting time.

The use of cement clinker and limestone flour as a mineral binder, grinding them with the rest of the components makes it possible to obtain a more uniform, cheaper mixture than when using cement.

The introduction of a certain fraction of sand into the building mixture, which is subjected to joint grinding with the other components of the building mixture, also allows you to apply a thinner, even layer of the mixture on the surface, which leads to a significant reduction in shrinkage deformation and better adhesion to the surface and finishing materials.

Thus, the joint grinding of the components of the claimed building mixture to a specific surface of 400 m ² / kg provides a finely divided homogeneous mixture, which can be applied to the surface with an even thin layer, which provides a significant reduction in shrinkage deformation. The inventive building mixture allows you to get the necessary strength and mobility of the mixture when performing finishing, plastering and masonry work. The resulting mixture after grinding can be stored in dry form for up to 2 months. Water is added immediately before work is performed until a given mobility is obtained.

Example

To obtain a building mixture is taken:

- 10.0 kg. (50% by weight) of cement clinker of the Montenegrin cement plant:

- 2.9 kg (14.5% by weight) of limestone flour of the Iskitim plant;

- 7.0 kg (35% by weight) of the sand of the Ob river fraction of less than 5.0 mm;

- 0.02 kg PAA (0.1% by weight);

- 0.04 kg of tylose (0.2% by weight);

- 0.04 kg Vinnopas (0.2% by weight);

- 2 liters of water (added after preparation to a given mobility).

Proportional to the fractional compositions, a joint grinding is carried out in a grinder - disassembler E 656 RE with an electric drive power W = 2.2 kW.

The main characteristics of the grinder are as follows:

- the size of the crushed material is not more than 20 mm

- rotor speed - 4000 min ^-1 .

The crushed material is a dry and clean product. Samples were prepared from the obtained building mixture and subjected to tests at W / C = 0.2, i.e. 2 L of water. Water is added until the desired mobility is obtained.

The strength of the resulting mixture was determined on samples - cubes measuring 7.07 × 7.07 × 7.07 cm after 7 and 28 days of hardening under normal conditions by testing the samples on a P-50 press. The compressive strength was measured. Mobility was determined according to GOST 5802-86. Draft of a cone of 7 cm (Pk2) on the IKP Stroitsnil device. Shrinkage strains were determined on 40 × 40 × 160 mm samples on an IZV-2 device. Tests showed that the compressive strength was R _cr = 15.8 ÷ 17.7 MPa. density q = 1700-1940 kg / m ³ , average linear shrinkage 0.3 mm / m, water holding capacity = 99.8%.

Thus, the inventive building mixture can reduce shrinkage deformation, increase strength, reduce delamination, increase water retention and improve adhesion to the surface

The building mixture, including mineral binder, sand, polymer additives and water, is characterized in that it contains a joint grinding product of the mineral binder, sand fraction less than 5 mm to a specific surface of 400 m ² / kg, and clinker and limestone are used as the mineral binder flour, and as a polymer additive - a mixture of Tylose, Vinnopas and polyacrylamide (PAA), in the following ratio of components, wt.% by weight:

Cement clinker - 50;

Sand - 34-36;

Calcite (limestone flour) - 13-15;

PAA - 0.1;

Tylose - 0.2;

Vinopas 0.05-0.2;

Water - until a given mobility is obtained.

Claims (8)

Building mixture, including mineral binders, sand, additives and water, characterized in that it contains a joint grinding product of a mineral binder, sand fractions of less than 5 mm and a mineral additive to a specific surface of 400-450 m ² / kg, and as a mineral binder they use cement clinker and lime flour, and as a mineral additive they use a mixture of tylose, vinnapas and polyacrylamide PAA brand flocculant Praestol, in the following ratio, wt.%: cement clinker - 50; sand - 34 -36; lime flour (calcite) - 15-13; PAA - 0.1; tylose - 0.2; winnest - 0.05 -: - 0.2; water - until a given mobility is obtained.