RU2731482C1 - Plaster composition for finishing aerocrete - Google Patents

Abstract

FIELD: construction.SUBSTANCE: invention relates to construction materials. Heat-insulating dry construction mixture for plastering external and internal walls of buildings, constructed from aerocrete blocks, includes, wt%: slaked lime 37.06–44.85; white cement 5.93–12.56; filler – aluminosilicate ash microspheres 22.88–40.02; ground aerocrete waste with specific surface of 650 m/kg 6.84–12.60; plasticiser C-3 0.38–0.52; redispersible powder Vinnapas 8031 H 1.60–2.74; mineral additive – a mixture of hydrosilicates and calcium hydroaluminosilicates 2.22–6.28.EFFECT: high crack resistance of finishing coatings.1 cl, 6 tbl

Description

The invention relates to the field of building materials, namely to multicomponent heat-insulating dry building mixtures based on a lime-cement binder, and can be used as a finishing compound for plastering the external and internal walls of buildings constructed from aerated concrete blocks of various densities.

Known heat-insulating plaster compositions containing slaked lime, expanded perlite, Portland cement, quartz sand, foam glass, polypropylene fiber, limestone flour, foaming agent based on sodium lauryl sulfate, methylcellulose, a water-soluble additive based on modified RU starch, and a water-soluble additive based on modified RU starch, and 2490234, priority date 06.02.2012, publication date 20.08.2013, Usatova T.A., Kalinin A.Ya., Keskinov A.L., Golunov S.A., Babayan I.S., Taletskaya T.V., VA Avdeev VA) [1].

The closest in technical essence and the achieved result is a mixture based on binders and mineral filler, used for plastering predominantly walls made of aerated concrete, including weight. %: lime-cement binder 35.6-48.9, quartz sand 3.5-13.1, cellulose ether 0.07-0.13, adhesive additive - redispersible powder 1.1-2 (based on vinyl acetate monomers, verstat and acrylate), a porous aggregate from waste aerated concrete production with a particle size of up to 5 mm 44.4-51.2, which has a polyfractional composition, with the following ratio of fractions, wt. %: fraction 2.5-5 mm - 17.2-32.0, fraction 1.25-2.5 mm - 14.6-22.6, fraction 0.63-1.25 mm - 11.2- 15.8, fraction 0.315-0.63 mm - 11.3-13.7, fraction 0.14-0.315 mm - 9.2-15.2, fraction 0-0.14 mm - 9.1-28, 1 (RU 2309133, priority date 02/26/2006, publication date 10/27/2007, VF Chernykh, SA Udodov, AE Durov) [2].

The disadvantage of these dry mixes is the rather low crack resistance of the coatings obtained when using them due to the high average density, low adhesion strength with aerated concrete, significant shrinkage deformations, low ultimate tensile finishing coatings, low water-holding capacity of the finishing composition.

The objective of the invention is to eliminate these disadvantages.

The problem is solved by the fact that the formulation of a heat-insulating dry construction mixture for plastering the external and internal walls of buildings built from aerated concrete blocks, including fluff lime, white cement, filler, crushed waste from the production of aerated concrete, a plasticizer, polymer and mineral additive, contains as filler ash microspheres aluminosilicate, as ground waste of aerated concrete production - ground waste of aerated concrete with a specific surface area of 650 m ² / kg, as a plasticizer - additive C-3, as a polymer additive - redispersible powder Vinnapas 8031 N, as a mineral additive - a mixture hydrosilicates and hydroaluminosilicates of calcium, with the following ratio of components, wt. %:

Fluff lime 37.06-44.85 White cement 5.93-12.56 Ash microspheres, aluminosilicate 22.88-40.02 Crushed waste from aerated concrete production 6.84-12.60 Plasticizer S-3 0.38-0.52 Redispersible powder Vinnapas 8031 N 1.60-2.74 Mineral additive 2.22-6.28

A dry construction mixture is prepared in the form of a homogeneous mixture consisting of fluff lime, ash microspheres of aluminosilicate, a mineral additive in the form of a mixture of hydrosilicates and hydroaluminosilicates of calcium, crushed waste from aerated concrete production, white cement, C-3, Vinnapas 8031 N, which is diluted with water before use to the state of an easily movable plastic paste.

The following materials were used to prepare the composition:

- slaked lime (fluff) with an activity of 86%, specific surface area of 1050 m ² / kg (meets the requirements of GOST 9179-77) [3];

- white cement without mineral additives (meets the requirements of GOST 965-89) [4];

- ash microspheres, aluminosilicate (meets the requirements of TU 5951-001-87368658-15). The main indicators of ash microspheres of aluminosilicate are shown in Table 1.

- crushed waste from the production of aerated concrete, obtained by crushing aerated concrete crushed to a specific surface area S _beats = 650 m ² / kg;

- С-3 - a plasticizing additive obtained by the interaction of technical sulfonic acids and naphthalene lingosulfonates with formaldehyde (meets the requirements of TU 5730-004-97474489-2007). The main indicators of the additive C-3 are shown in table 2.

- additive Vinnapas 8031 N - water-redispersible dispersion powder of a terpolymer of ethylene, vinyl laurate and vinyl chloride. The main indicators of the Vinnapas 8031 N additive are shown in table 3.

- a mineral additive is a modifying additive based on a mixture of hydrosilicates and hydroaluminosilicates. The main indicators of the mineral additive are presented in table 4.

Specific examples of formulations of a heat-insulating plaster composition for finishing aerated concrete and the properties of coatings based on it are given in table. 5, 6.

To study the properties of the presented formulations of a heat-insulating plaster composition for finishing walls from aerated concrete blocks, the following techniques were used.

To determine the average density, the samples of the studied finishing coating were dried to constant weight at a temperature of 100-110 ° C and weighed with an error of 0.1 g. The average density of the material ρ _av (kg / m ³ ) was calculated by the formula:

where m is the mass of the sample, kg;

V - sample volume, m3, determined by the formula:

where a, b, c are the dimensions of the sample edges, kg;

To assess the crack resistance of the coatings, the crack resistance coefficient K _{tr was used} , determined by the formula:

where ε _pre - ultimate elongation, mm / mm;

ε _us - shrinkage deformations during hardening, mm / mm.

The compressive strength of the samples obtained as a result of the research was determined using a testing machine of the IR 5057-50 type in accordance with GOST 5802-86 [6] on cube samples measuring 0.0707 × 0.0707 × 0.0707 m at the age of 28 days. The range of applied forces, depending on the force transducer used, varied from 50 to 50,000 N, the traverse speed was changed using built-in speed controllers in the range from 0.06 to 6 m / h. The compressive strength R _comp (Pa) of the finishing coating samples was determined by the formula:

where P - destructive force, N;

F is the cross-sectional area of the sample before testing, m ² .

To assess the adhesive strength of the adhesion of the coating based on the composition being developed with the aerated concrete substrate, the method of punching off the stamp (normal pull-off) was used according to GOST 31356-2007 [7]. The investigated finishing composition was applied to aerated concrete. After 27 days of storage of the samples, square stamps with a size of 0.05 × 0.05 m were glued to the finishing coating using epoxy glue (EDP-TU 0751-018-48284381-00). After 24 hours of storage, the force required to detach the die from the test specimen was measured using a dynamometer. To determine the adhesion strength of the coating to the substrate R _adg (MPa), the following formula was used:

where P is the separation force, MN;

F is the contact area of the stamp with the coating, m ² .

The coefficient of constructive quality for adhesion strength KKK _ss , taking into account the positive effect of reduced density and increased adhesion strength, was determined by the formula:

where R _ad is the adhesion strength of the coating to the substrate, MPa;

ρ _cf - material density, g / cm ³ .

The water-holding capacity of the developed finishing composition was carried out in accordance with GOST 5802-86 [6]. Before the start of the study, 10 sheets of blotting paper 0.15 × 0.15 m in size, previously weighed with an error of up to 0.1 g, were placed on a glass plate 0.15 × 0.15 m in size and 5 mm thick. a layer of gauze, and a metal ring having an inner diameter of 0.10 m and a height of 12 mm was placed on top, after which the installation was weighed. The thoroughly mixed plaster was placed flush with the edges of the metal ring and the unit was weighed. After 10 minutes, the metal ring with the plaster composition was carefully removed together with gauze, the blotting paper was weighed with an error of up to 0.1 g. The water-holding capacity of the finishing mixture V (%) was determined by the formula:

where m ₁ is the mass of blotting paper before testing, kg;

m ₂ is the mass of blotting paper after testing, kg;

m ₃ - weight of the installation without finishing mixture, kg;

m ₄ - weight of the installation with the finishing mixture, kg.

LIST OF REFERENCES

1. The composition of the heat-insulating plaster mixture: US Pat. 2490234 Rus. Federation: IPC С04В 41/50, С04В 28/04, С04В 111/20 T.A. Usatova, A. Ya. Kalinin, A.L. Keskinov, S.A. Golunov, I.S. Babayan, T.V. Taletskaya, V.A. Avdeev; applicant and patentee State budgetary institution of the city of Moscow "City coordination expert and scientific center." ENLACOM - No. 2012103939/03, filed 06.02.2012; published 20.08.2013.

2. Dry mix for aerated concrete plaster: US Pat. 2309133 Rus. Federation: IPC С04В 38/00. V.F. Chernykh, S.A. Udodov, A.E. Durov; applicant and patent holder GOU VPO "Kuban State Technological University" (KubSTU) - No. 2006105946/03, app. 02/26/2006; publ. 27.10.2007.

3. GOST 9179-77. Construction lime. Specifications [Text]. - Instead of GOST 9179-70; entered 1979-01-01. - Moscow .: IPK Publishing house of standards, 2001. - 7 p.

4. GOST 965-89. Portland cements are white. Specifications [Text]. - Instead of GOST 965-78; entered 1990-01-01. - Moscow: IPK Publishing house of standards, 2002. - 7 p.

5. GOST 12966 - 1985. Purified technical aluminum sulfate. Specifications [Text]. - Instead of GOST 12966 - 1975; entered 1985. - 30 - 09. - Moscow: Ministry for the production of mineral fertilizers of the USSR; Moscow: IPK publishing house of standards, 1985. - 12 p.

6.GOST 5802-1986. Building solutions. Test methods [Text]. - Instead of GOST 5802 - 1978; entered 1986 - 01 - 07. - Moscow: Ministry of Construction of Russia, 1985 .-- 15 p.

7. GOST 31356-2007 Dry building mixtures based on cement binder. Test methods. - M .: MNTKS, 2008 .-- 16 p.

Claims (2)

Heat-insulating dry mortar for plastering the external and internal walls of buildings built of aerated concrete blocks, includes: fluff lime, white cement, filler, crushed waste from the production of aerated concrete, plasticizer, polymer and mineral additive, characterized in that it contains ash as a filler aluminosilicate microspheres, as ground waste of aerated concrete production, ground waste of aerated concrete with a specific surface area of 650 m ² / kg, as a plasticizer additive C-3, as a polymer additive redispersible powder Vinnapas 8031 N, as a mineral additive a mixture of hydrosilicates and calcium hydroaluminosilicates in the following ratio of components, wt%: Fluff lime 37.06-44.85 White cement 5.93-12.56 Ash microspheres, aluminosilicate 22.88-40.02 Crushed waste from aerated concrete production 6.84-12.60 Plasticizer S-3 0.38-0.52 Redispersible powder Vinnapas 8031 N 1.60-2.74 Mineral additive 2.22-6.28