RU2635420C1 - Plastifying additive for building solutions - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: additive contains, wt %: calcium ammonium nitrate 44-45; potassium nitrate 35-38; superplasticizer - the rest, which is used as polycarboxylate - a water-soluble copolymer of unsaturated carboxylic acids and alkoxyalkylene polyglycol ethers of unsaturated carboxylic acids, produced by radical polymerization in the aqueous solution.

EFFECT: increasing the workability, preserving the mobility and reducing the water demand.

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Description

FIELD OF THE INVENTION

The invention relates to the construction industry, in particular to a plasticizing additive for mortars, and can be used in cement and other hydraulic binders as a plasticizing additive of multifunctional action in the production of ready-mixed concrete, concrete for massive structures, special concrete.

State of the art

It is known astringent, including semi-aquatic gypsum, lime (calcium oxide) and a silica-containing additive, while silica fume and optionally C-3 superplasticizer, obtained on the basis of sodium salts of the condensation product of naphthalene sulfonic acid and formaldehyde, are used as additives in the following ratio of components, wt.%: semi-aquatic gypsum 78.4-81.6; lime (calcium oxide) 8-9; silica fume 10-12; superplasticizer C-3 0.4-0.61 (see Pat. RU No. 2081076, IPC С04В 11/00, С04В 111: 20, publ. 10.06.1997)

The disadvantage of this binder is its high water demand.

Known plasticizing additive for building mixtures, including calcium-containing sludge is a waste product, while as a calcium-containing sludge, it contains sludge formed during the neutralization of waste processing of aluminum alloys with lime milk in the presence of coagulants of ferrous sulfate and aluminum sulfate, containing the following components, mass. %: CaCO ₃ - 36-44; Fe (OH) ₃ - 17-19; Al (OH) ₃ - 15-18; Ca (OH) ₂ - 10-12; Mg (OH) ₂ - 4-8; Mg (CO) ₃ - 4-6; CaSO ₄ - 2-4; SiO ₂ - 1-2 s (see Pat. RU No. 2093487, IPC С04В 22/06, С04В 28/02, publ. 10/20/1997)

The disadvantage of this plasticizing additive is the low workability and mobility of the building mixture.

Known complex modifying additive for mortar containing a mineral component and cellulose ether as a water-retaining active ingredient, while it additionally contains water in the following ratio of components, mass. hours: mineral component 100; cellulose ether 0.1-1.0; water 8-50.

The complex modifying additive contains a mineral filler and / or filler as a mineral component.

The complex modifying additive contains at least one additional active ingredient selected from the group consisting of redispersible polymer powders, as well as water-soluble plasticizing, air-entraining, water-repellent, biocidal, accelerating and delaying the setting mortar, pigmenting additives.

A known method of obtaining a mortar by mixing a binder with a complex modifying additive, using a modifying additive according to any one of the above three points in the following ratio of mortar components, mass. hours: modifying additive 100; astringent 10-45.

In the method, when mixing a binder with a complex modifying additive, water is additionally added (see US Pat. RU No. 2364576, IPC С04В 24/38, С04В 103/30, publ. 08/20/2009).

The disadvantage of this additive is the lack of vitality, low mobility and workability of the mortar.

The closest in technical essence and the achieved positive effect and adopted by the authors for the prototype is a comprehensive additive for concrete, including bitumen, lignosulfonate and water, while the additive in the form of granules additionally contains cellulose fibers as a builder in the following ratio of composition components, masses. %: bitumen 5-25; cellulose fiber 15-35; water 1-10; lignosulfonate rest up to 100%

The additive additionally contains aluminosilicate in the amount of 5-15 mass. % and / or superplasticizer C-3 in an amount of 15-25 mass. % (see Pat. RU No. 2230045C2, 12/27/2004)

The disadvantage of this complex additives is the low mobility and workability of the mortar.

Disclosure of invention

The objective of the invention is the development of plasticizing additives for mortars, which increase workability, maintaining mobility and reducing water demand.

The technical result that can be obtained using the proposed invention is to increase workability, maintain mobility and reduce water demand.

The technical result is achieved using a plasticizing additive for mortars, including a superplasticizer, while it additionally contains ammonium nitrate of calcium and potassium nitrate of derivatives of isomers of ethoxylated alkylenes, and polycarboxylate is used as a superplasticizer - a water-soluble copolymer of unsaturated carboxylic acids and alkoxyalkylene polyethylene glycol acids by radical polymerization in an aqueous solution in the following ratio of com Ponents, mass. %:

calcium ammonium nitrate 44-45 potassium nitrate 35-38 superplasticizer rest

Thus, polycarboxylate is used as a superplasticizer, while polycarboxylates are surfactants, which are water-soluble copolymers of unsaturated carboxylic acids and alkoxyalkylene-polyglycol ethers of unsaturated carboxylic acids obtained by radical polymerization in aqueous solution. It is produced in the form of a liquid and is intended for cement and other hydraulic binders as a plasticizing additive of multifunctional action.

The essence of obtaining plasticizing additives for mortars is as follows.

The components of plasticizing additives for mortars are taken in the following ratio in mass. %: - calcium ammonium nitrate 44-45; potassium nitrate 35-38; superplasticizer - the rest, which is used as a polycarboxylate - a water-soluble copolymer of unsaturated carboxylic acids and alkoxyalkylene-polyglycol ethers of unsaturated carboxylic acids, obtained by radical polymerization in an aqueous solution, is dosed according to the formulation and loaded into the mixer, the mixer motor is turned on, the components are mixed for 15 20 minutes, incubated for 15-24 hours, depending on the properties of the raw materials used, the resulting mixture has sufficient fluidity Tew, then it is Packed in containers for delivery to the consumer.

Brief description of drawings and other materials

In FIG. 1 gives a plasticizing additive for mortars, product characteristics, table 1.

In FIG. 2 - the same classification in accordance with GOST 24211-08, GOST 30459, table 2.

The implementation of the invention

Examples of specific performance of obtaining plasticizing additives for mortars.

Example 1. The components of plasticizing additives for mortars are taken in the following ratio in wt.%: - calcium ammonium nitrate 40; potassium nitrate 30; the rest is a superplasticizer, which is used as a polycarboxylate - a water-soluble copolymer of unsaturated carboxylic acids and alkoxyalkylene-polyglycol ethers of unsaturated carboxylic acids, obtained by radical polymerization in an aqueous solution, dosed according to the recipe and loaded into the mixer, turn on the mixer motor, mix the components for 10 minutes incubated for 10 hours, depending on the properties of the raw materials used, test the resulting mixture for workload tackability, fluidity, strength characteristics and adhesive ability of mortar, release form in the form of a brown liquid, then it is packaged in a container for delivery to the consumer.

Example 2. Carried out analogously to example 1, but the components of the plasticizing additives for mortars in wt.% Take in the following amounts: calcium ammonium nitrate - 44; potassium nitrate - 35; superplasticizer - the rest, dosed in accordance with the recipe and loaded into the mixer, turn on the mixer motor, mix the components for 15 minutes, hold for 15 hours, depending on the properties of the raw materials used, test the resulting mixture for workability, fluidity, strength characteristics and the adhesive ability of the mortar, then it is Packed in containers for delivery to the consumer.

Example 3. Carried out analogously to example 1, but the components of the plasticizing additives for mortars in wt.% Take in the following quantity: calcium ammonium nitrate 45; potassium nitrate 38; superplasticizer - the rest is dosed in accordance with the recipe and loaded into the mixer, the mixer motor is turned on, the components are mixed for 20 minutes, kept for 24 hours, depending on the properties of the raw materials used, the resulting mixture is tested for workability, fluidity, strength characteristics and the adhesive ability of the mortar, the release form in the form of a brown liquid, then it is Packed in containers for delivery to the consumer.

Example 4. Carried out analogously to example 1, but the components of the plasticizing additives for mortars in wt.% Take in the following amount: calcium ammonium nitrate 50; potassium nitrate 40; superplasticizer - the rest, dosed in wt.% in accordance with the recipe and loaded into the mixer, turn on the mixer motor, mix the components for 25 minutes, hold for 28 hours, depending on the properties of the raw materials used, test the resulting mixture for workability, fluidity , strength characteristics and adhesive ability of mortar, release form in the form of a brown liquid, then it is Packed in containers for delivery to the consumer.

The tests of the mixture according to examples 1, 2, 3, 4 for workability, fluidity, strength characteristics, adhesive ability, storage and shelf life of the mortar showed the following: the mixture obtained in example 1 has low mobility, plasticity of the mortar and strength characteristics, mixture according to examples 2 and 3 is the most optimal (see Fig. 1, table 1 and Fig. 2, table 2), corresponds to GOST 24211, GOST 30459, as it increases the mobility of the mortar mixture from Pc 1 to Pc 4, without reducing the strength and at all stages of hardening, it reduces water consumption during mixing up to 25%, increases the air content in the mixture, significantly increases the plasticity of the mortar, is an antifrosty additive, promotes concrete with increased frost resistance, crack resistance, increases the adhesive ability of mortar to the application surface, while the recommended range the dosage of the additive is 0.3-0.6% by weight of the binder for the finished product, the introduction of additional superplasticizer is not required, the release form in the form of brown liquids, the content of chlorine ions is less than 0.1%, while at the temperature of concrete hardening up to -5 ° С the dosage of the additive by weight of cement is 1%; at a hardening temperature of concrete up to -10 ° С, the dosage of the additive based on the mass of cement is 2%; at a hardening temperature of concrete up to -15 ° С, the dosage of the additive based on the mass of cement is 3%; a shelf life of 1 year from the date of manufacture in a hermetically sealed container at a temperature not lower than + 5 ° С and not higher than + 40 ° С, while the mixture according to example 4 also showed good aforementioned characteristics, as in examples 2 and 3, but increased costs components of plasticizing additives, which significantly increased the cost.

Thus, the plasticizing additive is used as a strong plasticizer for the production of ready-mixed concrete, reinforced concrete and prestressed concrete structures, the additive does not contain components that cause corrosion of reinforcing bars, while the additive is used both to increase workability of mixtures and to reduce cement consumption or increase strength concrete. The recommended dosage range of the additive is 0.3-0.6% by weight of the binder for the finished product, the greatest effect of the additive is achieved when it is added to the concrete mix after short mixing of the remaining components with mixing water, it is possible to meter the additive also with mixing water, it is allowed the use of the additive with other accelerating / decelerating additives, the mobility retention time of at least 2 hours, the additive is available in liquid form, is a ready-to-use product and does not require further era tio dissolution or cooking.

The invention in comparison with the prototype and other known technical solutions has the following advantages:

- increases the mobility of the mortar mixture from Pc 1 to Pc 4, without compromising strength in all periods of hardening;

- reduces water consumption during mixing up to 25%;

- increases air content in the mixture;

- increases the plasticity of the solution;

- is an antifrosty additive;

- contributes to the production of concrete with increased frost resistance, crack resistance;

- increases the adhesive ability of the mortar to the application surface;

- increases the strength of the concrete structure.

Claims (2)

A plasticizing additive for mortars, including a superplasticizer, characterized in that it additionally contains ammonium nitrate of calcium and potassium nitrate of derivatives of isomers of ethoxylated alkylenes, and a polycarboxylate is used as a superplasticizer - a water-soluble copolymer of unsaturated carboxylic acids and alkoxyalkylene polymerization carboxylic acids in an aqueous solution in the following ratio of components, mass. %: calcium ammonium nitrate 44-45 potassium nitrate 35-38 superplasticizer rest

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