RU2260572C1 - Additive for modification of gypseous bindings, building mortars and concretes prepared on their base - Google Patents

Abstract

FIELD: production of construction materials.

SUBSTANCE: the invention is pertaining to the field of construction materials, namely, to the additives used at production of gypseous bindings, building mortars and concretes on their base. The technical result is simplification of the method of fulfillment of the works, an advantage to produce the additive with in advance predicted in a wide spectrum properties improving the consumer wanted features of the gypseous bindings, building mortars and concretes on their base and realization of the method in the industry. The additive for modification of gypseous bindings, building mortars and concretes on their base contains (in mass %): a hydraulic binding - 50-90; an active mineral component - 10-45; a plasticizing additive - 0.1-2; a regulator of time of hardening and solidification - 0.001-1; a stabilizing agent - 0.001-5. At that in the capacity of a hydraulic binding the additive contains portland cement of any species, white cement, a color cement, an alumina cement, hydraulic lime or their mix in any ratio, as the active mineral component it contains a carryover, ash of a rice or buckwheat hull, ash and drosses of thermoelectric power station, a ceramic dust, wastes of bricks production, other stoneware, aluminum compounds, a fine quartz sand, micro silica, a pumice stone, cullet, silica gel, tuff, diatomite, white soot, an aerosil or their mix in any ratio, in the capacity of a plasticizing additive - a superplasticizer containing compounds on the basis of sulfonated melamineformaldehyde compounds and-or complexes on their basis, compounds on the basis of modified lignosulphonated naphthaleneformaldehyde compounds or complexes on their base, a compound on the base of the modified lignosulfonates, or compounds on the basis of the water soluble carboxylaled polymeric compounds, or their mix in any ratio, in the capacity of regulators of time of hardening and solidification - a retardant of solidification of gypsum, in the capacity of the stabilizing agent - a water-soluble cellulose ether. At that in the capacity of gypseous bindings use one of the following components or the mixed in any ratio semiaquatic gypsum or anhydrite. Batching of the additive is realized in amount of 10-40 % from their mass, and a value of its specific surface makes 550-7000 m²/kg.

EFFECT: the invention ensures simplification of implementation of the method of production of the additive with in advance predicted in a wide spectrum properties improving the consumer wanted features of the products.

10 cl, 3 ex, 1 tbl

Description

The invention relates to the field of building materials, namely, additives used in the production of gypsum binders, mortars and concrete based on them.

A known additive for the modification of gypsum binders containing silica fume and superplasticizer C-3, obtained on the basis of the sodium salts of the condensation product of naphthalene sulfonic acid and formaldehyde, in the following ratio of components (% by weight): semi-aquatic gypsum 78.4-81.6; lime (calcium oxide) 8-9; silica fume 10-12; superplasticizer C-3 0.4-0.6 (see RF patent No. 2081076, IPC: C 04 B 11/00, C 04 B 111/20, published June 10, 1997 in Bull. No. 16). The additive is made together with a gypsum binder, increasing the amount of processing. Moreover, the obtained gypsum binder has insufficient water resistance, frost resistance, insufficient softening coefficient, and has a short setting time.

A known additive for the modification of gypsum binders, including C-3 superplasticizer based on the sodium salts of the condensation product of naphthalene sulfonic acid with formaldehyde, as well as zeolite rock calcined at 800 ° C and a silica brick fight, the additive contains C-3 superplasticizer in the form of dry powder at the following ratio of components of the additive: (% by weight): dry powder of superplasticizer C-3 1.5-4.0; zeolite additive, calcined at 800 ° C 12-14; silica brick fight 82-86 (see RF patent No. 2074137, IPC: C 04 V 11/00, C 04 V 111/20, published on 02.27.97 in Bull. No. 6). The additive is made separately from the gypsum binder, reducing the processing volume by several times, after which it is introduced into the gypsum binder (100 wt.%) In an amount of 5-15% by weight. This additive allows you to increase the strength of gypsum binders and save up to 15% gypsum, however, for the manufacture of the additive requires significant energy consumption for: 1. preliminary firing of zeolite rock at a temperature of 800 ° C for 8 hours; and 2. joint grinding of zeolite rock and battle of silicate brick with dry powder of S-3 superplasticizer in a ball mill for 1 hour. The obtained gypsum binder in this case has insufficient water resistance and frost resistance, an insufficient softening coefficient, and has a short setting time.

Known additive for the modification of gypsum binders (as a gypsum binder is taken semi-aquatic gypsum) of the following composition: 1. hydraulic binder - Portland cement 15-25; 2. The active mineral component is pozzolanic additive 10-25; 3. stabilizer - an aqueous dispersion of polyvinyl acetate polymer or divinyl styrene latex (see A.V. Volzhensky et al. Mineral binders. - M .: Stroyizdat, 1979, p. 459-461.) The resulting gypsum binder has the best parameters for adhesive properties , durability, however, the preparation of a gypsum binder containing an aqueous dispersion is technologically difficult, in addition, the resulting gypsum binder has insufficient water separation, compressive strength and tensile strength when bent, frost resistance, softening coefficient.

Known adopted for the prototype additive for the modification of gypsum binders (see Yu.M. Bazhenov, V.F. Korovyakov, G.A. Denisov - Technology of dry building mixtures, M., 2003, Publishing House of the Association of Construction Universities, p.20- 25, 48), containing the following components: hydraulic binder - Portland cement of any kind; active and inert finely divided silica-containing materials - fly ash, ceramic dust, pumice, ashes and slag of thermal power plants, glass breakage, waste products from brick and other ceramic products, fine quartz sand, silica fume, silica gel, etc. Materials and superplasticizer in the ratio 1: (1 ... 2) :( 0.1 ... 0.25). In this case, the obtained maximum value of the specific surface is 500 m ² / kg, and this is not always sufficient to improve the physical and mechanical properties of gypsum binders, mortars and concrete based on them.

The objective of the invention is to obtain a modifying additive that improves the physico-mechanical properties of gypsum binders, mortars and concrete based on them.

The expected technical result is to simplify the technology of work, in the possibility of obtaining additives for the modification of gypsum binders, mortars and concrete based on them with properties that are previously predicted in a wide range of properties that improve the consumer properties of gypsum binders, mortars and concrete based on them and realize it in industry.

For this, the additive for modifying gypsum binders, mortars, and concrete based on them includes a hydraulic binder, an active mineral component, a plasticizing additive, a setting and hardening time regulator, while it additionally contains a stabilizer, and the components have the following ratio (% by weight) : hydraulic binder 50-90; active mineral component 10-45; plasticizing additive 0.1-2; regulator of setting and hardening time 0,001-1; stabilizer 0.001-5. Moreover, as a hydraulic binder it contains one of the following components or Portland cement of any kind mixed in any proportion, white cement, non-ferrous cement, alumina cement, hydraulic lime, contains one of the following components as an active mineral component or mixed in any proportion fly ash, ash rice husk, buckwheat husk ash, ash and slag from thermal power plants, ceramic dust, waste from brick and other ceramic products, fine quartz sand, silica fume, pem y, glass break, silica gel, tuff, diatomaceous earth, carbon black, aerosil, waste from the production of aluminum compounds, as a plasticizing additive it contains a superplasticizer containing one of the following components or compounds in any proportion based on sulfonated melamine-formaldehyde compounds and / or complexes on them basis, compounds based on sulfonated naphthalene formaldehyde compounds or complexes based on them, compounds based on modified lignosulfanates, or compounds based on hydrogen soluble carboxylate polymers, as regulators of setting time and hardening, contains a gypsum hardening inhibitor, as a stabilizer contains water-soluble cellulose ether, the specific surface area is 550-7000 m ² / kg. Moreover, as a gypsum binder it contains one of the following components or semi-aquatic gypsum or anhydrite mixed in any proportion, and the dosage of the additive is carried out in an amount of 10-40% by weight of the gypsum binder.

In practice, the additive for the modification of gypsum binders, mortars and concrete based on them contains the following components (% by weight):

- hydraulic binder - Portland cement of any kind, white cement, non-ferrous cement, alumina cement, hydraulic lime, etc. - 50-90;

- the active mineral component contains one of the following components or mixed in any proportion - fly ash, rice husk ash, buckwheat husk ash, ashes and slag of thermal power plants, ceramic dust, waste from brick and other ceramic products, fine silica sand, silica fume, pumice, glass battle, silica gel, tuff, diatomaceous earth, soot, aerosil, waste from the production of aluminum compounds, etc. - 10-45;

- a plasticizing additive - a superplasticizer based on sulfonated melamine-formaldehyde compounds and complexes based on them, or based on sulfonated naphthalene formaldehyde compounds and complexes based on them, or based on modified lignosulfonates, or based on water-soluble carboxylate polymers - 0.1-2;

- regulators of setting and hardening - moderator gypsum hardening of 0.001-1;

- stabilizer - water-soluble cellulose ether - 0.001-5.

The value of the specific surface area increases significantly from 500 m ² / kg in the prototype to 550-10000 m ² / kg in the described invention. As a gypsum binder, semi-aquatic gypsum or anhydrite is used.

The production of additives for the modification of gypsum binders, mortars and concrete based on them includes two stages. First, the dosed components of the additive are pre-mixed in a forced action mixer. At the second stage, the resulting mixture is fed to a continuous-action centrifugal-shock type activator-mixer, for example, SCS-450, after which the additive is packaged in a container for shipment to the consumer. The dosage of the additive is carried out in an amount of 10-40% by weight of the gypsum binder.

To illustrate the production of a gypsum binder with certain properties, examples of specific performance are given below, moreover, semi-aquatic gypsum of the G-15 brand is used as semi-aquatic gypsum.

Example 1

For experimental verification of the claimed composition of the modifying additive, the following mixture of ingredients was prepared (% by weight):

1. gypsum binder - semi-aquatic gypsum - 80;

2. additive for gypsum modification - 20;

wherein the addition of the following composition (% by weight):

1. hydraulic binder, Portland cement - 87.9;

2. active mineral component, silica fume - 10;

3. superplasticizer based on polycarboxylates - 1;

4. retarder of gypsum hardening, natural tartaric acid - 0.1;

5. water-soluble cellulose ether, hydroxyethyl cellulose - 1.

The resulting composition has high mobility and high resistance to weathering, significantly improved technological characteristics, increased mobility, viability of the mixture, while the value of the specific surface of the additive is 4000 m ² / kg

Example 2

For experimental verification of the claimed composition of the additive, the following mixture of ingredients was prepared (% by weight):

1. gypsum binder - semi-aquatic gypsum - 70;

2. additive for gypsum modification - 30;

wherein the addition of the following composition (% by weight):

1. hydraulic binder, Portland cement - 87.9;

2. active mineral component, silica fume - 10;

3. superplasticizer based on polycarboxylates - 1;

4. retarder of gypsum hardening, natural tartaric acid - 0.1;

5. water-soluble cellulose ether, hydroxyethyl cellulose - 1.

The resulting composition has increased frost resistance and strength, therefore, the scope of use is expanding due to the possibility of perceiving large external loads and use for exterior decoration, mobility is increased, the viability of the mixture is preserved, while the value of the specific surface of the additive is 4000 m ² / kg. Thus, the technological characteristics are significantly improved.

Example 3

For experimental verification of the claimed composition of the additive, the following mixture of ingredients was prepared (% by weight):

1. gypsum binder - semi-aquatic gypsum - 90;

2. additive for the modification of gypsum - 10;

wherein the addition of the following composition (% by weight):

1. hydraulic binder, Portland cement - 58;

2. active mineral component, glass break (up to 3 mm) - 40;

3. a superplasticizer based on polycarboxylates - 0.9;

4. retarder of gypsum hardening, natural tartaric acid - 0.1;

5. water-soluble cellulose ether, hydroxyethyl cellulose - 1.

Despite the fact that only 10% of the additive is used to modify gypsum binders, the resulting composition has high mobility and high resistance to weathering, while the specific surface area of the additive is 600 m ² / kg.

For the experimental determination of the parameters of the claimed composition, samples were made in the form of a prism 40 × 40 × 160 mm. The results are shown in the table.

Table Options Suggested composition Example 1 Example 2 Example 3 Prototype Compressive Strength, MPa: 28 days 52 55 35 thirty 2. Tensile strength in bending, MPa: 28 days thirty 36 16 12 3. Setting time, min: Start thirty fifty thirty 10 ending 60 90 60 twenty 4. Water-solid ratio 0.18 0.20 0.18 0.26 5. Frost resistance, cycles fifty 60 40 thirty 6. Softening coefficient 0.86 0.9 0.82 0.8 7. Water retention ability,% 99 99 99 70-75 8. The mobility of the mixture according to Suttard, mm after 5 min 250 250 250 200 in 10 minutes 250 250 250 150 after 15 min 250 250 250 70

Claims (10)

1. The additive for the modification of gypsum binders, mortars and concrete based on them, including a hydraulic binder, an active mineral component, a plasticizing additive, a setting time and hardening, characterized in that it additionally contains a stabilizer, and the components have the following ratio, wt. %: Hydraulic binder 50-90 Active mineral component 10-45 Plasticizing additive 0.1-2 Setting and setting times 0.001-1 Stabilizer 0.001-5 2. The additive according to claim 1, characterized in that as a hydraulic binder contains one of the following components or mixed in any proportion Portland cement of any kind, white cement, colored cement, alumina cement, hydraulic lime. 3. The additive according to claim 1, characterized in that, as an active mineral component, it contains one of the following components or mixed in any proportion fly ash, rice husk ash, buckwheat husk ash, CHP ash and slag, ceramic dust, brick waste and other ceramic products, fine quartz sand, silica fume, pumice, glass break, silica gel, tuff, diatomite, white soot, aerosil, aluminum compound production waste. 4. The additive according to claim 1, characterized in that as a plasticizing additive contains a superplasticizer. 5. The additive according to claim 4, characterized in that it contains one of the following or mixed in any proportion compounds based on sulfonated melamine-formaldehyde compounds and / or complexes based on them, compounds based on sulfonated naphthalene formaldehyde compounds or complexes based on them, as a superplasticizer, compounds based on modified lignosulfonates or compounds based on water-soluble carboxylate polymers. 6. The additive according to claim 1, characterized in that as a regulator of the setting time and hardening contains a moderator hardening of gypsum. 7. The additive according to claim 1, characterized in that the stabilizer contains a water-soluble cellulose ether. 8. The additive according to claim 1, characterized in that as gypsum binders use one of the following components or mixed in any proportion gypsum semi-aquatic or anhydrite. 9. The additive according to claim 1, characterized in that the dosage of the additive is carried out in an amount of 10-40% by weight of the gypsum binder. 10. The additive according to claim 1, characterized in that the value of its specific surface is 550-7000 m ² / kg