RU2359947C2 - Film-forming material for curing of newly placed concrete - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention pertains to the area of construction operations and may be employed for protection from dehydration of new concrete in construction of highways and airdromes, ameliorative and water engineering. Film-forming material for maturing of newly placed concrete contains styrene-butadiene latex "БС" 50, stiffener - sodium carboxymethyl cellulose, stabiliser ethoxylated octyl phenol "ОП-10", filler - kaolin clay, dispersing agent "НФ", adhesive additive - methylol melamine derivations mixture and water, with the following ratio of components, wt %: above said latex - 57-66, said stiffener - 0.18-0.35, said stabiliser - 0.60-0.65, kaolin clay - 14.3-16.0, dispersing agent "НФ" - 0.73-0.80, said adhesive additive - 0.03-0.04, water - the rest.

EFFECT: getting environmentally safe low toxic film-forming material, reduced specific moisture permeability of the film, enhanced strength of concrete.

6 tbl

Description

The invention relates to the field of construction production and can be used to protect against dehydration of freshly laid concrete in the construction of roads and airfields, reclamation and hydraulic engineering.

A known composition for protective coating of concrete, which contains wt.%: Bone glue 3-4, laundry soap 70% 3-4, 30% solution of expanded polystyrene in a mixture of solvents acetone: gasoline in a ratio of 1: 1 39-50, water 42-55. Achieved accelerated drying of the composition and increase the strength of concrete (see RF patent No. 2148561, IPC С04В 26/00, С04В 40/04, С04В 41/63).

However, this composition is characterized by the presence of environmentally and fire hazardous components.

The closest in technical essence and the achieved result is a composition for the protection of freshly laid concrete, which contains, wt.%: High melting paraffin hydrocarbons 3-25; low melting paraffin hydrocarbons 3-40; fatty acids of the fraction C10 - C13, or C10 - C16, or C17 - C20. or C10 - C21 0.5-3; fatty acids of the C21 - C25 fraction or their bottoms 1-6: triethanolamine, or diethylethanolamine, or morpholine 0.3-5, potassium hydroxide, or potash, or aqueous ammonia solution 0.3-2; latex 2-25; complexing agent 0.035-0.7; dispersant 0.05-3; unsaturated polymeric oxidized acids or alkyd resins 0.05-8; driers 0.001-0.03; water is the rest. The composition is characterized by low viscosity and the absence of thixotropy, high water retention capacity and light reflectance of the coating formed on the concrete (see RF application for invention No. 92000579, IPC 41B 41/63).

The disadvantage of this composition is the increase in viscosity during storage, as well as the complex cooking process, which consists in heating and homogenizing the ingredients to a temperature of 70-90 ° C, including higher fatty acids and alkaline components.

The technical task of the invention is to obtain an environmentally friendly and low-toxic film-forming material on a water basis for the care of freshly laid concrete, characterized by a low specific moisture permeability of the film, which allows to increase the strength of concrete while reducing cost.

The essence of the invention lies in the fact that the film-forming material for the care of freshly laid concrete containing latex, thickener, dispersant. water, according to the solution, contains BS 50 latex butadiene styrene, sodium carboxymethyl cellulose as a thickener, NF dispersant as a dispersant, and OP-10 ethoxylated octylphenol as a dispersant, filler - kaolin and an adhesive additive - a mixture of methylolmelamine derivatives, in the following ratio of components, wt. .%:

specified latex 57-66; specified thickener 0.18-0.35; specified stabilizer 0.60-0.65: kaolin (brand KR) 14.3-16.0: dispersant NF 0.73-0.80; specified adhesive additive 0.03-0.04; water rest.

The process of preparing the proposed film-forming material is reduced to dosing and mixing the components. The latex is loaded into the reactor, then a 20% solution of OP-10, solution (NaKMU) -6% solution of 7MF blanose, 50% dispersion of kaolin, glycazine or metazine.

The film-forming material is applied to the fully finished surface of the concrete coating after the disappearance of the water film from it by special machines - dispensers of film-forming materials of the DS-105A type.

By the degree of impact on the human body, BS-50 latex is a low-hazard and low-toxic product of hazard class 4 according to GOST 12.1.007-76. Excipient OP-10 (ethoxylated octylphenol) and NF dispersant (methylenebisnaphthalene sulfonate disodium), textile auxiliary glycazine or methazine (a mixture of methylolmelamine derivatives) sodium carboxymethyl cellulose (Blanose 7MF or 85/500 “O” type) is dangerous 3 hazard classes according to GOST 12.1.007-76 and make up about 15% by weight.

The use of latex in the film-forming material in combination with OP-10, sodium carboxymethyl cellulose provides low toxicity. stable material with a shelf life of at least 12 months, having a low specific moisture permeability of the film.

A decrease in latex content below 57 wt.% Leads to a decrease in water-holding ability. An increase in the content of latex over 66 wt.% Is impractical due to the increase in the cost of the material.

The use of other latexes as a binder, such as styrene-butadiene SKS-65GP, leads to a decrease in the protective ability due to the production of more rigid films.

The use of MTs-100 domestic methyl cellulose, sodium carboxymethyl cellulose of technical grade 70/450 "O" and 85/500 "O" in the same quantities as 7MF blanose as a thickener does not allow obtaining the material with the required viscosity, an increase in the recipe .% of these thickeners reduces the stability of the material during storage and increases the specific moisture permeability of the film.

An increase in kaolin filler over 16 wt.% Also leads to an increase in the specific moisture permeability of the film, delamination of the composition during storage, a decrease below 14.3 wt.% Leads to an unjustified rise in price of the composition. Specific compositions and properties of the film-forming material are shown in tables 1 and 2.

table 2 Composition Song Number By
table 1 Mass fraction of solids,%, 45 ± 2 Conditional viscosity at a temperature of (20 ± 2) ° С according to the B3-246 viscometer with a nozzle diameter of 4 mm, 18 ± 2 The specific moisture permeability of the film from the composition on the surface of freshly laid concrete after 3 days, g / cm ² , not more than 0,055 Water dilution resistance one 43.0 21 0.058 Acc. 2 43.0 twenty 0,048 Acc. 3 43.0 16 0,047 Acc. four 43.0 22 0,050 Acc. 5 43.9 twenty 0,045 Acc. 6 42.8 16 0,055 Acc. 7 46.5 twenty 0,060 Acc. 8 44.6 eighteen 0,039 Acc. 9 46.8 twenty 0,037 Acc. 10 46.7 twenty 0,040 Not acc. eleven 47.0 twenty 0,035 Acc. 12 47.0 21 ** 0,036 Acc. Concrete without care - - 0.290 Acc.

* Cement-sand mixture composition B / C = 0.4

** Thicken during storage

Preparation of film-forming material for the care of freshly laid concrete

1. Preparation of a solution of an auxiliary substance OP-10

Name of ingredients Parts of the mass, wt.% Mass fraction of solids in solution,% Substance auxiliary OP-10 20,0 20,0 Water 80.0 - Total: 100.0 20,0

Pour water with a temperature of (65 ± 5) ° С into the container and, with stirring, introduce the auxiliary OP-10 substance, which is heated until liquefied. Stirred for at least 30 minutes until a clear solution is obtained.

2. Preparation of carboxymethyl cellulose solution - Blanose 7MF

Name of ingredients Parts of the mass, wt.% Mass fraction of solids in solution,% Carboxymethyl Cellulose - Blanose 7MF 6.0 6.0 Water 94.0 - Total: 100.0 6.0

Pour water with a temperature of (35 ± 5) ° С into the container, add carboxymethyl cellulose - blanose 7MF, mix until completely dissolved for 60 minutes and leave to swell for at least 24 hours.

3. Preparation of kaolin dispersion

Name of ingredients Parts of the mass, wt.% Mass fraction of solids in solution,% Kaolin 50,0 50,0 Dispersant NF 2.5 2.5 Water 47.5 - Total: 100.0 52,5

The ingredients are loaded into a ball mill in the order specified in the recipe. The processing time of the dispersion (24 ± 1) h at ambient temperature.

4. Preparation of film-forming material

Name of semi-finished products Parts of the mass of solids in the mixture per 100 p.m. dry matter latex Mass fraction of solids in semi-finished products,% Latex BS-50 one hundred 47 Solution OP-10: 1.99 twenty Including OP-10 1.99 Water - Solution NaKMTS-blanose: 0.60 10.0 Including blanose 0.60 Water - Kaolin dispersion: 50.00 50,0 Including kaolin 47.62 Dispersant NF 2,38 Water - Glikazin 0.1 one hundred

At ambient temperature, the latex, OP-10 solution, NaKMC-blanose solution, kaolin dispersion and glycazine are loaded into the reactor at ambient temperature. Stirring lead 1.5-2 hours.

Claims (1)

A film-forming material for the care of freshly laid concrete containing latex, a thickener, a dispersant, water, characterized in that it contains butadiene styrene BS 50 latex, sodium carboxymethyl cellulose as a thickener, NF dispersant as a dispersant, and an additional ethoxylated octylphenol OP-10 stabilizer, filler - kaolin and adhesive additive - a mixture of methylolmelamine derivatives in the following ratio of components, wt.%:
specified latex 57-66 specified thickener 0.18-0.35 specified stabilizer 0.60-0.65 kaolin 14.3-16.0 dispersant NF 0.73-0.80 specified adhesive additive 0.03-0.04 water rest