RU2577047C1 - Dry construction mix - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: dry plastering mix, including Portland cement, sand, methyl cellulose, contains sand with size modulus of 1.43 with maximum sand size of 1.25 mm or with size modulus of 2.41 and maximum sand size of 2.5 mm.

EFFECT: production of high-quality finishing material with increased water-retaining and plasticising properties, high adhesive properties.

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Description

 The invention relates to the field of building materials, namely the production of dry building mixtures, and can be used for the preparation of mortars for the production of high-quality internal finishing plastering works.

Recently, dry mixes for the preparation of mortar have become widespread, allowing to bring technologies to a qualitatively new level, namely, guaranteed consistently high quality of mixtures, imparting special properties to them through the use of various chemical additives, reducing losses in production due to the fine packing of dry mixes, reduction of transportation costs by reducing the volume of transportation, etc.

In accordance with the standard (GOST 28013-98), mortars must comply with the main quality indicators: mobility, water retention ability, delamination, average density, and after hardening must have compressive strength.

Known dry building mixture containing in wt. h: cement 45-55, sand 45-55, plasticizer based on methyl cellulose and methoxypropyl cellulose 0.4-0.5, lime mixture for mining drilling SIGB 0.5-2.0 (see US Pat. RU 2119467, IPC C04B 28/02, publ. 09/27/1998).

The closest analogue to the proposed invention is a dry building mixture containing in parts by weight: cement 30-40, sand 60-70, methyl cellulose 0.03-0.06 (see US Pat. RU 2184098, IPC C04B, publ. 27.06 .2002).

The objective of the invention is to obtain mortars with high water holding capacity and stable characteristics.

This object is achieved in that the dry building mixture, including Portland cement, sand and methyl cellulose, contains sand with a particle size modulus of 1.43 with a maximum sand size of 1.25 mm, 2.41 with a maximum sand size of 2.5 mm and 1.92 - obtained as a result of proportional mixing of sand with particle size modules of 1.43 and 2.41, with the following ratio of components:

Sand: Portland cement by weight - 9-11

Methyl cellulose,% by weight of Sand + Portland cement - 0.03-0.06.

The invention is as follows. Portland cement (characteristics are shown in Table 1) are mixed with sand having a particle size modulus of 1.43-2.41 (characteristics are shown in Tables 2 and 3) and methyl cellulose. After mixing, the finished mixture is packaged in paper bags.

Table 4 shows the specific compositions of the described dry mix.

To test the dry mixture, mortars are prepared from the indicated compositions (Table 4) by adding water to the mixture.

Tests are carried out on samples - cubes with dimensions of 70.7 × 70.7 × 70.7 mm, made on a porous base at the age of 28 days.

The obtained test results are given in table. 5.

As can be seen from the table. 5 data, the described dry mortar provides obtaining mortars with stable characteristics and high water holding capacity of 96-98%. The addition of methyl cellulose leads to a saving in cement, significantly reduces delamination, and also allows more efficient use of sands with a low modulus of fineness in the compositions of low-grade solutions (no more than M25).

Claims (1)

A dry mortar comprising Portland cement, sand and methyl cellulose, characterized in that it contains sand with a particle size modulus of 1.43 and a maximum sand size of 1.25 mm or with a particle size modulus of 2.41 and a maximum sand size of 2.5 mm in the following ratio components:
Sand: Portland cement by weight - 9-11
Methyl cellulose,% by weight of Sand + Portland cement - 0.03-0.06.