RU2396235C1 - Raw material mixture - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to field of construction materials and can be used as thin-layered hydroinsulation protective coating of concrete and other porous surfaces in industrial and civil construction. Raw material mixture contains, wt %: Portland cement 30.3-32.3, sand with maximal fraction size 0.63 mm 40.4-40.9, finely milled dolomitic limestone with specific surface equal 200 m²/kg, 8.1-8.6, complex additive 3.2-3.7, water 16.0-16.5, said complex additive contains, wt %: microsilica with specific surface equal 2000 m²/kg, 47-49, alumina cement 24.5-25.0, gypsum CaSO₄·2H₂O 9.8-10.2, plasticiser C-3 3.7-4.0, silicic acid sol H₄SiO₄ with density 1.014 g/cm³ and pH=3.5±0.5 3.0-3.4, bentonite clay with specific surface equal 500 m²/kg, 10.0-10.4.

EFFECT: reduction of unmixing, increase of water-holding capacity, reduction of water absorption, increase of protective coating compression strength.

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Description

The invention relates to the field of building materials and can be used as a thin-layer waterproofing protective coating of concrete and other porous surfaces in industrial and civil engineering.

Known raw mix consisting of the following components, wt.%: Portland cement - 7.73-8.98; silica fume - 68.04-68.42; hydrated lime - 6.26-7.1; sol-containing additive - 0.003-0.0058; amelose-containing product - 0.017-0.025 and water - 16.7-16.72 (Temnikov Yu.N. Colored dry building mixes for decoration and decoration of improved quality. The dissertation for the degree of candidate of technical sciences. - SPb., 2005, p. 58).

The disadvantage of this raw material mixture is increased stratification, reduced water retention, increased water absorption and reduced value of compressive strength.

Known raw mix consisting of the following components, wt.%: Portland cement - 23.00-28.81; sand - 59.00-64.00; montmorillonite clay with Ssp.≥150 m ² / kg - 0.69-0.83; silica fume with Ssp. = 2000 m ² / kg - 1.16-1.30; CMID-4 additive - 0.19-0.22; 20% solution of sol of orthosilicic acid with pH = 3-4 - 0.14-0.17 and water - 10.01-10.48 (RU No. 2305671, C04B 41/65, Bull. No. 25 dated 09/10/2007 )

The disadvantage of this raw material mixture is increased separability, reduced water retention capacity, increased water absorption and reduced value of compressive strength.

Closest to the claimed building mixture is a raw material mixture consisting of the following components, wt.%: Portland cement - 24-28; sand represented by molding waste of metallurgical production - 56-60; additives - 8-10 and water - 8-10 (RU No. 21399841, C04B 38/10, Bull. No. 29 dated 10/20/1999).

The disadvantage of this raw material mixture is increased separability, reduced water retention capacity, increased water absorption and reduced value of compressive strength.

The objective of the invention is the creation of a new raw material mixture for a thin layer of waterproofing protective coating, which would allow to achieve a technical result, consisting in reducing the delamination, increasing water retention capacity, reducing water absorption and increasing compressive strength.

The problem is solved in that the raw material mixture, including Portland cement, sand, additive and water, uses sand with a maximum fraction size of 0.63 mm as sand, and as an additive contains a complex additive consisting of silica fume with a specific surface Ssp. = 2000 m ² / kg, alumina cement, gypsum - CaSO ₄ · 2H ₂ O, plasticizer C-3, sol of silicic acid - H ₄ SiO _{4 with a} density of 1.014 g / cm ³ and a pH of 3.5 ± 0.5 and bentonite clay with specific surface Ssp. = 500 m ² / kg in the following ratio of components, wt.%:

Silica fume with Ssp. = 2000 m ² / kg 47-49 Alumina cement 24.5-25.0 Gypsum - CaSO ₄ · 2H ₂ O 9.8-10.2 Plasticizer S-3 3.7-4.0 Silicon Sol - H ₄ SiO ₄ density of 1.014 g / cm ³ and pH = 3.5 ± 0.5 3.0-3.4 Bentonite clay with S beats. = 500 m ² / kg 10.0-10.4

and additionally contains finely ground dolomitic limestone with a specific surface S beats = 200 m ² / kg in the following ratio of components, wt.%:

Portland cement 30.3-32.3 Sand with a maximum fraction size = 0.63 mm 40,4-40,9 Finely ground dolomitic limestone with S beats. = 200 m ² / kg 8.1-8.6 Complex supplement 3.2-3.7 Water 16.0-16.5

A new compared with the known raw material mixture is the combination of the known components of Portland cement, sand, water with dolomitic limestone and a complex additive consisting of silica fume, alumina, gypsum - CaSO ₄ · 2H ₂ O, SP-3 plasticizer, silica sol and bentonite clay .

The additional use of dolomitic limestone improves the processability of the mortar mixture, which consists in increasing the mobility of the mortar mixture with lower water consumption, which results in a decrease in the water absorption of the hardened protective material, as well as the use of a complex additive as an additive, reduces delamination and increases the water retention capacity of the mortar mixture, and also has plasticizing and activating effect, when used, the water consumption decreases n 10% and the amount of hydrate compounds is increased, as judged by differential thermal analysis, because losses due to dehydration of hydrosilicates increase by 26 relative%.

The presence in the complex additive of finely dispersed bentonite clay increases the water-holding ability of the mortar mixture, makes the mixture stable in time and reduces the delamination.

The above ensures the formation of a dense finely porous structure of the hardened material, which is characterized by a lower value of water absorption and an increased value of strength.

According to the authors and the applicant, this composition of the raw mix is not known, and we can conclude that the invention meets the condition of patentability “novelty”.

The claimed invention is industrially applicable and can be used as a waterproofing protective coating of any porous surface.

Below is information confirming the possibility of carrying out the invention.

An example of a specific implementation of the manufacture of the raw mix.

Preparation of complex additives.

1. Dose:

- silica fume with Ssp. = 2000 m ² / kg;

- alumina cement;

- gypsum - CaSO ₄ · 2H ₂ O;

- plasticizer C-3;

- bentonite clay with Ssp. = 500 m ² / kg.

2. Dosage components are thoroughly mixed in a cyclic screw mixer, distributing all the components evenly until a homogeneous mass is obtained.

3. Dose the liquid component of the complex additive — sol of silicic acid — H ₄ SiO _{4 with a} density of 1.014 g / cm ³ and a pH of 3.5 ± 0.5.

4. Dose:

- Portland cement;

- sand with a maximum fraction size = 0.63 mm;

- dolomitic limestone with Ssp. = 200 m ² / kg;

- water.

5. The dosed solid and liquid components of the complex additive are introduced into the dosed water, which is located in a cone-shaped container equipped with a compressed air supply for mixing the complex additive with water.

6. Dosage components according to claim 4 and claim 5 by gravity are transported to the mixer and mixed thoroughly to obtain a finished raw material mixture, which is recommended to be used for a waterproofing thin-layer protective coating of a porous base in industrial and civil engineering.

The protective coating hardens in natural conditions at a positive temperature. The obtained physical and mechanical characteristics are presented in the table.

Tests were conducted according to GOST 5802-86.

An analysis of experimental data shows that the inventive raw material mixture provides a 40% reduction in delamination, water retention capacity increases by 6%, water absorption decreases by 32% and strength increases by 42%.

Claims (1)

A raw material mixture including Portland cement, sand, an additive and water, characterized in that sand is used as sand with a maximum fraction size of 0.63 mm, and as an additive contains a complex additive consisting of silica fume with a specific surface area S beat equal to 2000 m ² / kg, alumina cement, gypsum CaSO ₄ · 2H ₂ O, plasticizer C-3, sol of silicic acid H ₄ SiO _{4 with a} density of 1.014 g / cm ³ and pH 3.5 ± 0.5, and bentonite clay with a specific surface area S beats equal to 500 m ² / kg, in the following ratio of components, wt.%:
Silica fume with S beats 2000 m ² / kg 47-49 Alumina cement 24.5-25.0 Gypsum CaSO ₄ · 2H ₂ O 9.8-10.2 Plasticizer S-3 3.7-4.0 Silicic acid sol H ₄ SiO ₄ density of 1.014 g / cm ³ and pH 3.5 ± 0.5 3.0-3.4 Bentonite clay with S beats 500 m ² / kg 10.0-10.4
and additionally contains finely ground dolomitic limestone with a specific surface S beats equal to 200 m ² / kg, in the following ratio of components, wt.%:
Portland cement 30.3-32.3 Sand with maximum size fractions of 0.63 mm 40,4-40,9 Thin-layer dolomitic limestone with S beats 200 m ² / kg 8.1-8.6 Complex supplement 3.2-3.7 Water 16.0-16.5