RU2361835C1 - Granulated filler for concrete mix based on crushed glass, composition of concrete mix for manufacture of concrete construction products, method for manufacturing of concrete construction products and concrete construction product - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: granulated filler for concrete mix is arranged in the form of granules with size of 0.5-10.0 mm, comprising nucleus and shells, where nucleus is produced by granulation of mixture of the following components jointly ground to specific surface of 150-250 m²/kg - siliceous component - crushed glass - and alkaline metal hydroxide at their mass ratio of 0.70-0.95 : 0.05-0.30 with binder - aqueous solution of sodium silicate with density of 1.2-1.3 g/cm³ in amount of 0.1-7.0% from mixture, shell shaping on nucleus surface is carried out in medium of dry dusty mixture of jointly ground quicklime and sodium fluorsilicate at their mass ratio of 0.85-0.95 : 0.05-0.15, with further hardening to strength of at least 2.1 MPa. Concrete mix for manufacture of construction products includes the following components, wt %: above mentioned filler 5-40, binder 10-25, fine filler 15-45, water - the rest. Method for production of concrete construction products includes mixing of above mentioned mix components, moulding of construction products, soaking in molds and heat-and-moisture treatment at atmospheric pressure and temperature of 85-95°C. Concrete construction product produced by above described method.

EFFECT: higher water resistance and frost resistance, reduced heat conductivity with preservation of strength parametres of concrete construction products, lower energy inputs in process of products making due to lower energy inputs during filler production.

4 cl, 1 ex, 2 tbl

Description

The invention relates to the production of building materials and can be used to obtain concrete building products subjected to heat and moisture treatment during hardening, for civil and industrial construction.

A known method of producing concrete building products subjected to heat and moisture treatment during hardening, the composition of the concrete mixture and aggregate in the form of granulate fractions of 5-20 mm, made from dispersed ash and slag waste from incinerators and concrete building product. A method for producing concrete building products includes mixing mechanically activated Portland cement (22-23 wt.%), Building sand (28-34 wt.%), Aggregate in the form of granulate (44-49 wt.%) And water, molding building products, holding in forms and their subsequent heat and humidity treatment in a steaming chamber at atmospheric pressure [RF Patent No. 2201410, cl. 7 C04B 28/02, 2000].

The disadvantages of this method, concrete mixture and aggregate is that the aggregate used does not increase the water resistance of concrete building products subjected to heat and moisture treatment during hardening, as well as high energy consumption when receiving mechanically activated Portland cement and granulate.

Granular aggregate for concrete mixtures in the form of granules consisting of a core made of fiberglass and a shell made of cement-ash mixture and a concrete building product is also known. Raw granules before being used as aggregate for concrete mix are preliminarily subjected to heat-moisture treatment in a steaming chamber at atmospheric pressure with isothermal exposure for 6 hours at a temperature of 80-90 ° C [USSR Author's Certificate No. 1219548, cl. 4 C04B 14/24, 1983].

The disadvantages of this aggregate are the high energy and labor costs in obtaining fiberglass, the formation of granules from it by crushing and subsequent heat and moisture treatment of raw granules before using them as a filler, which increases the cost of finished construction products. The use of the indicated aggregate does not contribute to an increase in water resistance and a significant decrease in the thermal conductivity of concrete building products subjected to heat and moisture treatment during hardening.

Closest to the proposed solution is a method of obtaining concrete building products subjected to heat and moisture treatment during hardening, the composition of the concrete mixture and the concrete building product. A method of obtaining concrete building products includes mixing Portland cement (10-25 wt.%), Sand (15-35 wt.%), Aggregate in the form of expanded clay gravel (5-40 wt.%) And water (the rest), molding building products, aging in molds and subsequent heat-moisture treatment in a steaming chamber at atmospheric pressure according to the 2 + 6 + 2 mode and the temperature of isothermal exposure 85-95 ° С [Gershberg O.A. Technology of concrete and reinforced concrete products. - M .: Stroyizdat, 1971, pp. 98-102, 305-313].

The disadvantages of this method of producing concrete building products and concrete mix is that the resulting concrete building products after heat and moisture treatment have low water resistance and heat-insulating ability.

Closest to the proposed solution is also a granular aggregate for concrete mix, consisting of a core and a protective shell. The core is made by granulation on a plate granulator of a mixture of dispersed silica-containing components - TPP ash (dispersion not less than 200 m ² / kg) and sludge from a biological wastewater treatment aeration station with a binder - ground lime (dispersion 500-600 m ² / kg) and gypsum ( with a brand name of at least 100 and a dispersion of at least 350 m ² / kg) in the ratio of the components of the mixture, respectively, 0.3: 0.5: 0.15: 0.05 by weight. After granulation, a 3-5 mm thick protective coating is applied to the core by wetting the core of the granule with liquid glass and dusting or rolling it on a disk or drum granulator with a dry, dusty mixture of lime, gypsum and mineral dispersed filler (ash from a thermal power station, state district power station, loam, etc. ) in the ratio of the components of the mixture, respectively, 0.35: 0.10: 0.55 by weight. After the formation of the granules with the aim of curing, heat and humidity treatment is applied at a temperature of 90 ° C with isothermal exposure for one hour [RF Patent No. 2077517, cl. 6 C04B 20/10, 1993].

The disadvantage of granular aggregate according to the prototype is that in the manufacture of concrete products, increased heat energy is required for heat and moisture treatment: first, granular aggregate is subjected to heat and moisture treatment, then a molded building product including the aforementioned aggregate, as well as the resulting concrete building products subjected heat and moisture treatment during hardening, have low water resistance, strength and heat-insulating ability.

The present invention solves the problem of increasing water resistance, reducing heat conductivity while increasing and maintaining the strength characteristics of concrete building products subjected to heat and moisture treatment during hardening, and reducing energy consumption in the manufacture of concrete products by reducing energy consumption in the manufacture of aggregate.

The technical result is achieved using granular aggregate for a concrete mixture made of silica-containing and lime-containing components. According to the proposed solution, it is made in the form of granules with a size of 0.5-10.0 mm, consisting of a core and a shell, where the core is obtained by granulating a mixture of co-milled to specific surface area of 150-250 m ² / kg of silica-containing component - cullet and alkali metal hydroxide with a mass ratio of 0.70-0.95: 0.05-0.30 with a binder - an aqueous solution of sodium silicate with a density of 1.2 -1.3 g / cm ³ in an amount of 0.1-7.0% of the mixture, the formation of a protective shell on the surface of the core of the granule is carried out in a dry dusty mixture of together ground lime quicklime and sodium silicofluoride with a mass ratio of 0.85-0 95: 0.05-0.15, followed by hardening to a strength of at least 0.12 MPa.

The technical result is achieved in that the concrete mixture for the manufacture of building products includes the above aggregate, binder, fine aggregate and water in the following ratio of components, wt.%: The specified aggregate is 5-40; astringent - 10-25; fine aggregate - 15-45 and water - the rest.

The technical result is achieved by the fact that the method of producing concrete building products from the above concrete mixture includes mixing its components, molding building products, holding in molds and subsequent heat and moisture treatment of products at atmospheric pressure and a temperature of 85-95 ° C.

The result is achieved using a concrete building product, characterized in that it is obtained in this way.

Component Feature:

1. As a binder used:

- Portland cement ZAO Belgorodcement according to GOST 10178-85. Cement grade 400. The normal density of the cement paste according to GOST 310.4-81 is 27.12%, the activity during steaming is 38.4 MPa, the activity during normal storage at the age of 28 days is 43.7 MPa;

- pozzolanic cement of the Fokinsky cement plant, Bryansk region according to GOST 22266-77, containing 30% tripoli. Cement grade 300. Normal density - 37.2%, activity during steaming 30.4 MPa, activity during normal storage at the age of 28 days - 31.7 MPa;

- slag Portland cement ZAO Belgorodcement according to GOST 10178-85. Cement grade 350. The normal density of the cement paste is 29.8%, the activity during steaming is 34.4 MPa, the activity during normal storage at the age of 28 days is 35.7 MPa.

2. As a silica-containing component for the manufacture of core aggregate used crushed battle of green container glass, Voronezh. Chemical composition, wt.%: SiO ₂ - 66.3; Al ₂ O ₃ - 10.1, Fe ₂ O ₃ - 1.2, TiO ₂ - 0.4, CaO - 6.1; MgO - 0.2; R ₂ O - 14.6; SO ₃ - 0.2, p.p.p. - no.

Cullet was crushed in a hammer mill and stored in storage bins.

3. As the alkali metal hydroxide used:

- sodium hydroxide according to GOST 2263-79;

- potassium hydroxide according to GOST 24363-80;

- lithium hydroxide according to GOST 8595-83.

4. Sodium silicofluoride Na ₂ SiF ₆ according to TU 6-09-1461-91.

5. For the manufacture of a protective envelope for the aggregate, quicklime construction lime was used by JSC “Building Materials”, Belgorod in accordance with GOST 9179-77.

6. As a fine aggregate of concrete mixtures used:

- natural quartz Volsky sand according to GOST 6139-2003;

- sand from screenings of crushing of quartzite sandstones - overburden obtained from the extraction of iron ore, Gubkin, Belgorod region. Fineness module 2.1 according to GOST 8736-85;

- artificial sand obtained in the processing of electrometallurgical slag, Stary Oskol, Belgorod region. Fineness modulus 1.7.

7. Tap water in accordance with GOST 23732-79.

8. When granulating powder together ground cullet with sodium hydroxide on a plate granulator, an aqueous solution of sodium silicate (water glass) was used as a binder according to TU 2385-001-54824507-2000 with a density of 1.2-1.3

g / cm ³ .

To obtain cores of granular aggregate in the implementation of the inventive method for producing concrete building products, crushed glass was dosed with sodium hydroxide by gravimetric method. The resulting mixture was loaded into a ball mill and mixed and milled until a specific surface of 150 ... 250 m ² / kg was reached. The ground material was fed to a standard plate granulator, where, when spraying an aqueous solution of liquid glass, core aggregates of a given size were obtained. The obtained core aggregates were directed to the formation of a protective shell by rolling into a drum mixer, into which a dry pulverulent mixture was also fed, i.e. similar to the method described in the patent of the Russian Federation No. 2077517. As a dry pulverized mixture, ground lime and sodium silicofluoride were used together with their mass ratio of 0.85-0.95: 0.05-0.15. The strength gain control of the granular aggregate during its hardening at ambient temperature by testing in a cylinder was carried out according to GOST 9758-86.

Example. Preparation of granular aggregate cores. Cullet (8 kg) and sodium hydroxide (2 kg), i.e. in a ratio of 0.80: 0.20 by weight (Table 1, mixture 1), ground in a mill together to a specific surface of 200 m ² / kg. The obtained powder material was fed to a plate granulator. On the surface of the powder by spraying was applied an aqueous solution of sodium silicate with a density of 1.25 g / cm ³ in an amount of 4% relative to the mass of the core aggregate. The rotation speed and the angle of inclination of the granulator plate controlled the diameter of the resulting cores, which in this case was 4.4–4.5 mm.

Obtaining a protective shell on the nuclei. The resulting cores were sent for dusting with a powder of lime (9 kg), ground together with sodium silicofluoride (1 kg), i.e. in a ratio of 0.90: 0.10 to obtain granules with a size of 5.0 mm (table 1, mixture 1). Dusting was carried out in a drum mixer.

Part of the obtained granular material after storage for 7 hours at ambient temperature was tested for strength by compression in a cylinder according to GOST 9758, the strength was 0.3 MPa; the rest was used in the preparation of concrete mixtures for the manufacture of samples of building products.

Preparation of concrete mix. The dosage of the components was carried out by the gravimetric method: 2 kg of Portland cement (20 wt.%, Table 1, mixture 1), 2.5 kg of quartz sand (25 wt.%) And 3.5 kg (35 wt.%) Of granular aggregate were mixed in screw mixer until smooth and 2 kg (20 wt.%) of water was added.

Samples were formed in the traditional way by filling in standard forms 2FK-100 according to GOST 10181-2000. The exposure time in the forms is 6 hours.

Heat and moisture treatment of concrete samples was carried out in a steaming chamber at atmospheric pressure according to the 2 + 6 + 2 mode and isothermal exposure temperature of 90 ° С, thus, the concrete mixture was prepared, samples were molded and their heat and moisture treatment was performed according to the known method [Gershberg O.A. Technology of concrete and reinforced concrete products. - M .: Stroyizdat, 1971, pp. 98-102, 305-313].

The granular aggregate according to RF patent No. 2077517 consisted of a core and a protective shell. A filler with a diameter of 15 mm after steaming according to the 2 + 1 + 2 h regime at an isothermal holding temperature of 90 ° C had a crushing strength of 0.21 MPa in the cylinder. In the manufacture of concrete samples, Portland cement was used as a binder, fine aggregate - Volsky sand, granular aggregate - according to the prototype (table 1, mixture 16).

table 2 Physico-mechanical properties of concrete building products after heat and moisture treatment Mix No. Heat and humidity treatment temperature, ° С Thermal conductivity, W / (m · K) Waterproof Concrete Brand The limit of compressive strength, MPa Notes one 2 3 four 5 6 one 90 0.44 AT 6 36.9 - 2 95 0.69 IN 2 22.5 Low activity of interaction of the aggregate with the matrix of concrete samples. 3 85 0.39 IN 2 30,2 Samples have large pores and structural defects of acceptable sizes. four 90 0.85 - 17.3 The aggregate practically does not interact with the concrete matrix, mechanical destruction occurs along the contact zones “aggregate-concrete”. 5 90 0.49 - 17.9 Partial dissolution of the inter-pore walls of the concrete matrix is observed. 6 90 0.44 AT 6 26.1 - 7 95 0.69 IN 2 14.8 Low activity of interaction of the aggregate with the matrix of concrete samples. 8 85 0.39 IN 2 20.1 Samples have large pores and structural defects of acceptable sizes. 9 90 0.85 - 9.3 The aggregate practically does not interact with the concrete matrix, mechanical destruction occurs along the contact zones “aggregate-concrete”. 10 90 0.49 - 9.9 Partial dissolution of the inter-pore walls of the concrete matrix is observed. eleven 90 0.44 AT 6 31.8 - 12 95 0.69 IN 2 19.5 Low activity of interaction of the aggregate with the matrix of concrete samples. 13 85 0.39 IN 2 20,2 Samples have large pores and structural defects of acceptable sizes. fourteen 90 0.85 - 12.3 The aggregate practically does not interact with the concrete matrix, mechanical destruction occurs along the contact zones “aggregate-concrete”. fifteen 90 0.49 - 11.9 Partial dissolution of the inter-pore walls of the concrete matrix is observed. 16 (prototype) 90 0.61 IN 2 28.9 Low activity of the interaction of the aggregate with the matrix of concrete samples, mechanical failure occurs in the contact zones.

Product samples were tested for strength (according to GOST 10180), thermal conductivity (according to GOST 7076-99) and water resistance (according to GOST 12730.5-84) were determined. The test results are shown in the table (mixture 1).

In the same way, wall products with other compositions of components were obtained (Table 1), the test results are shown in Table 2, mixtures 1-16.

Analysis of the test results of the properties of samples of concrete building products shown in table 2, shows the following.

1. Introduction to the composition of the concrete mixture of the inventive granular aggregate with a size of 0.5-10 mm, consisting of a core in the form of co-milled silica-containing component interconnected by liquid glass - cullet and alkali metal hydroxide, which is coated with a shell of ground lime and sodium silicofluoride in the claimed quantities, allows you to get durable concrete building products with reduced heat conductivity and water permeability, while due to the exclusion of steaming aggregate significantly reduced energy derived container wall products.

2. Reducing the amount of granular aggregate in the concrete mix to 5 wt.%, As well as the ratio in the core of the alkali metal hydroxide aggregate to 0.05 relative to the mass of cullet, the specific surface of the powder material of the core to 150 m ² / kg, the ratio of sodium silicofluoride in the protective shell of the granule to 0.05 with respect to the mass of lime and the diameter of the granules of the aggregate to 0.5 mm leads to a decrease in the strength of the granular aggregate, reduces its reactivity, which leads to an increase in thermal conductivity, sheniyu water resistance and strength of the resulting samples of concrete building products (mixture of 2, 7 and 12, Table 2), these compositions are adopted as the boundary.

A further decrease in the above ratios and parameters leads to a significant decrease in the physico-mechanical properties of concrete building products, therefore, the mixtures of mixtures 4, 9 and 14 go beyond the scope of the claimed compositions of concrete building products.

3. The use of granular aggregate in the composition of the concrete mixture in an amount of 40 wt.%, As well as the ratio in the core of the aggregate of alkali metal hydroxide in an amount of 0.30% relative to the mass of cullet, the specific surface of the powder material of the core up to 250 m ² / kg, silicofluoride in the protective shell of the granule to 0.15 with respect to the mass of lime and the diameter of the granules of the aggregate to 10 mm also reduces the strength of the granular aggregate. Excessively high activity of a granular aggregate of 10 mm in heat and moisture treatment of concrete products leads to the formation of large pores in their array with many structural defects, which also leads to an increase in thermal conductivity, a decrease in water resistance and strength of the resulting samples of concrete building products (mixtures 3, 8 and 13, Table 2), these compositions are accepted as boundary.

A further increase in the above ratios and parameters leads to a significant decrease in the physico-mechanical properties of concrete building products, therefore, the mixtures of mixtures 5, 10 and 15 go beyond the scope of the claimed compositions of concrete building products.

With an optimal ratio of components (mixture 1, 6 and 11, Table 1), the resulting concrete building products have the following advantages compared to the known ones:

1) strength indicators increase by 15-20%, the brand for water resistance at the same time increases from B2 to B6, thermal conductivity decreases by 1.5-1.7 times;

2) the inventive granular composite aggregate does not require autoclaving before entering it into the concrete mix, thereby reducing energy consumption when receiving building products.

When using raw concrete mixtures with boundary component ratios (mixtures 2, 3, 7, 8, 12, and 13, Table 1), the resulting concrete building products practically retain their water resistance and strength characteristics compared to the similar properties of the prototype.

In the process of applying a protective shell of ground lime and sodium silicofluoride to the core of the aggregate, the interaction of the components of the shell with liquid glass leads to a rapid increase in the strength of the granules of the composite aggregate at ambient temperature, which allows it to be used in the preparation of concrete mixtures without additional energy-intensive heat and moisture curing. In the process of moisture and moisture treatment of the claimed concrete building products in the cores of a granular aggregate, water-soluble sodium silicates are synthesized, which, penetrating the protective shell, provide extremely strong adhesion of the claimed granules with the concrete matrix of the product.

Granular aggregate according to the prototype when introduced into the composition of concrete building products in the process of heat and moisture treatment do not show any activity and do not interact with the concrete matrix in volume. When an external load is applied (compression and bending strength test), the destruction of these building products occurs along the boundaries of the contacts between these granules and concrete, i.e. their strong adhesion to concrete is not observed.

Obtained by the present method, concrete building products have improved adhesive properties with respect to plaster mortars.

Claims (4)

1. Granular aggregate for concrete mix made of silica-containing and lime-containing components, characterized in that it is made in the form of granules with a size of 0.5-10.0 mm, consisting of a core and a shell, where the core is obtained by granulating the mixture together ground to a specific surface 150-250 m ² / kg of silica-containing component - cullet and alkali metal hydroxide with a mass ratio of 0.70-0.95: 0.05-0.30 with a binder - an aqueous solution of sodium silicate with a density of 1.2-1.3 g / cm ³ in an amount of 0,1-7,0% of the mixture, forming a protective th shell on the surface of core granules produced in a medium dry milled together pulverulent mixture of quicklime and sodium silicofluoride at a weight ratio of 0.85-0.95: 0.05-0.15, followed by hardening to strength of at least 0.12 MPa. 2. Concrete mixture for the manufacture of building products, including aggregate according to claim 1, a binder, fine aggregate and water in the following ratio of components, wt.%:
specified placeholder 5-40 astringent 10-25 fine aggregate 15-45 water rest 3. The method of producing concrete building products from concrete mix according to claim 2, including mixing its components, molding building products, holding in molds and subsequent heat and moisture treatment of products at atmospheric pressure and a temperature of 85-95 ° C. 4. Concrete construction product, characterized in that it is obtained by the method according to claim 3.