RU2420469C1 - Dry construction mixture - Google Patents

Abstract

FIELD: construction. ^ SUBSTANCE: invention relates to dry construction mixtures and can be used in production of construction materials for laying outer and inner walls of buildings and structures, as well as plastering and finishing work. The dry construction mixture contains the following in wt %: portland cement 35-70, finely ground volcanic sand from Kantyshevo deposits 30-65. ^ EFFECT: high efficiency of construction works, possibility of using the mixture for different types of construction works, high strength and reliability of the construction material during multiple freezing to minus 20C and thawing. ^ 2 tbl

Description

The invention relates to dry building mixes and can be used in the production of building materials for laying the outer and inner walls of buildings and structures, as well as for plastering and finishing work.

Known gypsum binder containing active mineral additives, including oxides of calcium, aluminum, silica (see patent RU No. 2285677 IPC ⁹ С04В 7/13, publ. 20.10.2006).

The disadvantage of this binder is the need to introduce additional ingredients into the dry building mix to change the construction and technical properties, which leads to an increase in its cost.

Closest to the claimed technical solution is a dry cement mixture comprising Portland cement and a mineral additive (see patent RU No. 2148041 IPC ⁹ С04В 7/13, 28/02, publ. 04/27/2000).

The disadvantage of the prototype is the need for the introduction into a dry building mixture of additional ingredients to change the construction and technical properties, as well as the choice of additives to perform various types of work, which complicates the process and leads to an increase in its cost.

The objective of the invention is to increase the efficiency of construction work, the ability to change the construction and technical properties for various types of construction work.

The solution to the technical problem is achieved by the fact that in the known dry building mixture, including Portland cement and an active mineral additive, according to the invention, finely ground sand of volcanic origin of the Kantyshevsky deposit is used as an active mineral additive, with the following ratio of components to mass. %:

Portland cement - 30-75 sand of volcanic origin Kantyshevsky field - 65-30.

This invention will improve the efficiency of construction work, change the construction and technical properties of the mixture for various types of construction work, such as plastering, finishing, etc.

The invention is illustrated by tables, in which table 1 presents the compressive strength of various compositions of dry building mixtures, and in table 2 - the composition of the mineral additives of volcanic origin Kantyshevsky field.

Dry building mix is made as follows. As an active mineral additive, sand of volcanic origin from the Kantyshevsky deposit was used (see Table 2), which was previously crushed in a ball mill in order to increase the fineness of grinding and homogenize the resulting product. The grinding fineness was from 5 to 10 μm and the specific surface area was more than 4 × 10 ³ cm ² / g.

To prepare the dry building mixture, various quantitative ratios of the active mineral additives of volcanic origin of the Kantyshevsky deposit and cement were taken (see Table 1), mixed, prepared samples with dimensions of 40 × 40 × 160 mm in accordance with GOST 310-85 and tested 28-day samples for compressive strength.

Their frost resistance was also determined; for this, samples were placed in a freezer at a temperature of -20 ° C and subjected to alternate freezing and thawing at room temperature for 24 hours. After 25 cycles of alternate freezing and thawing, the samples were tested for compressive strength, the test results showed high strength and reliability of the dry mortar, even with repeated freezing and thawing.

From table 1 it is seen that, depending on the ratio of Portland cement and mineral additives, the area of their application was determined. Samples 2 and 3 can be used for the preparation of concrete, samples 4 and 5 for the preparation of masonry and plaster mortars. Sample 6 - for putty mortars, repairing cracks and leveling the plaster surface of internal and external walls.

When the content of the mineral additive is more than 75%, the strength of the mixture is sharply reduced (2 times), when the content is less than 30%, the efficiency of using the mixture decreases due to its high cost.

The proposed dry building mix will allow, in comparison with the prototype, to increase the efficiency of its use and use it for various construction works, changing the content of the mineral additive.

Strength characteristics of samples during compression of various compositions of dry mortar

Table 1 Sample The amount of partyland cement, wt.% The amount of mineral additives, wt.% Compressive strength of 28-day-old samples, MPa one one hundred 0 55.3 2 70 thirty 51.6 3 60 40 45.9 four fifty fifty 34.8 5 40 60 25.3 6 thirty 70 12,4

The mineralogical composition of the sand of the Kantyshevsky deposit

table 2 Mineral Chemical formula Amount, % Anorthite (Ca / Na / K) (Al, Si) 2Si ₂ O ₈ 40-45 Crossit Na ₂ (Fe, Mg) 5 (Si, Al) 8O ₂ (OH) ₂ 10-15 Quartz SiO ₂ up to 5 Aluminosilicates rest

Claims (1)

Dry building mix, including Portland cement and an active mineral additive, characterized in that finely ground sand of volcanic origin of the Kantyshevsky deposit is used as an active mineral additive in the following ratio of components, wt.%:
Portland cement 35-70 fine sand volcanic origin Kantyshevsky field 30-65