RU2169132C1 - Mix for manufacturing heat-insulating products - Google Patents

Abstract

FIELD: manufacture of light-weight concrete products used for guarding structures. SUBSTANCE: mix comprises composite binder based on activated alumosilicate waste, polystyrene foam filler, air-attracting and water-reducing additives and water. Binder in the form of activated waste comprises blast furnace or electrothermophosphoric granslag with specific surface of 2800- 3500 sq.cm/g and/or bauxite slime, and/or converter granslag ground to specific surface of 3200-3500 sq.cm/g and comprises, wt %: said waste, 55-95; cement clinker, 0-40; gypsum, 0-5; sodium chloride, 0- 5; powdered plasticizer C3, 0-3. Filling agent is polystyrene foam gravel having 10 mm fractions, bulk density of 10-30 kg/cubic m, granular composition being as follows, vol.%: 5-10 mm fractions, 15- 30:2.5-5 mm fractions, 20-35; 1.25-2.5 mm fractions, 30-40; and 0- 1.25 mm fractions, 20-30. Water-reducing additive is lignopan-B, ratios of mix components being as follows, wt %: binder, 53.57- 71.56; filling agent, 1.73-11.37; air-attracting additive, 0.06-0.31; water-reducing additive, 0.37-0.68; and water, the balance. EFFECT: heat-insulating polystyrene concrete having reduced heat conduction and desired strength, water, and frost resistance. 4 tbl

Description

 The invention relates to building materials, in particular to lightweight concrete mixtures for thermal insulation products used in building envelopes.

 A known mixture for the manufacture of thermal insulation products, including ash and slag binder, polystyrene gravel type PSV-S of two fractions with a grain size of 0.2 - 4.2 mm and 6.8-18.2 mm, fiberglass and water / 1 /.

The disadvantages of the known mixture are the multicomponent composition and reduced moisture resistance and frost resistance of concrete. The low frost and moisture resistance of concrete is due in this case to the type of binder used, namely the removal of slag-alkali binder from the stone, water-soluble alkaline (based on K ₂ O and Na ₂ O) compounds under possible atmospheric influences.

 The closest is a mixture for the manufacture of heat-insulating products, including a binder (Portland cement, slag Portland cement), polystyrene gravel fraction 0-20 mm (with a content, vol.%: Fractions 10-20 mm 0-20; 5-10 mm 30-70; 2 , 5-5 mm 20-60; 0-2.5 mm 0-10), air-entraining and plasticizing additives / 2 /.

The disadvantages of the known polystyrene concrete mixture for the manufacture of heat-insulating products is that the binders used do not allow to achieve the required thermal characteristics of concrete with known compositions without reducing the strength of the material, based on the required heat-shielding characteristics of enclosing structures according to SNiP 11-3-79 ^* (M., 1996 .).

 The technical problem is to create a heat-insulating polystyrene concrete with low thermal conductivity while ensuring the required strength, water resistance and frost resistance.

The problem is solved in such a way that in a mixture for the manufacture of heat-insulating products, including a composite binder based on activated technogenic wastes of an aluminosilicate composition, polystyrene foam aggregate, air-entraining and water-reducing additives and water, according to the invention, the binder as an activated technogenic waste contains blast furnace or electrothermophosphoric granular slag with specific surface of 2800-3500 cm ² / g, and / or bauxite sludge, and / or converter granular slag, ground to a specific surface 3200-3500 cm ² / g, with the following ratio of binder components, wt.%:
Indicated Waste - 55-95
Cement Clinker - 0-40
Gypsum - 0-5
Sodium Chloride - 0-5
Powdered C-3 - 0-3
the mixture as a filler contains polystyrene gravel fraction 0-10 mm, bulk density 10-30 kg / m ^{3 the} following grain composition, vol.%:
fractions
5-10 mm - 15-30
2.5-5 mm - 20-35
1.25-2.5 mm - 30-40
0-1.25 mm - 20-30
and as a water-reducing additive - lignopan-B, in the following ratio of components of the mixture, wt.%:
Astringent - 53.57-71.56
Placeholder - 1.73-11.37
Air entraining additive - 0.06-0.31
Water-reducing additive - 0.37-0.68
Water - Else
The proposed mixture differs from the known type of binder - low-clinker or non-clinker based on activated technogenic waste of aluminosilicate composition, fractional aggregate composition, providing minimal intergranular voidness, lignopan-B water-reducing additive content and component ratio.

The use of clinker-free or low-clinker composite binder grades 300 - 400 based on activated industrial waste leads to a decrease in the thermal conductivity of polystyrene concrete compared to polystyrene concrete on Portland cement by 15-25% while maintaining its density and strength. This is ensured by the action of the following factors:
- increase in the relative content of amorphized low-heat-conducting (λ _o = 0.2-0.3 W / (m • ^o C)) component of the minerals of the hardened composite binder by 1.5-2.5 times and a corresponding decrease in the proportion of crystallized high-heat-conducting (λ _î = 0.55-0.70 W / (m • ^o C)) clinker,
- a decrease in the relative number of pore capillaries and a decrease in the average pore size in the mortar part of concrete, due to a 10-20% decrease in the normal density of cement paste, which reduces the mean free path of phonons (thermal particles) in such a dispersed system as concrete. The use of a mixture of expanded polystyrene gravel with a bulk density of 10-30 kg / m ^{3 of a} fraction of 0-10 mm of the proposed fractional composition provides, while maintaining the density of polystyrene concrete, a decrease in its thermal conductivity in the state of operational humidity by 8-10% by increasing the number of low-temperature inclusions in the form of polystyrene foam spheroids gravel in a unit volume of concrete and the manifestation of the well-known in thermophysics disperse systems "phonon mean-range path effect". In addition, the strength of concrete is increased by 10-12% due to a decrease in the total intergranular voidness of the aggregate and, accordingly, a reduction in the consumption of air-entraining admixture required to obtain a cohesive concrete structure. The latter leads to a corresponding reduction in the volume of air involved in the cement stone, i.e. to its hardening.

 The introduction of a lignopane-B water-reducing additive into the polystyrene-concrete mixture, in addition to the plasticizing effect, leads to an increase in strength by 10-15% while maintaining the density of concrete. A decrease in mixing water consumption leads to a decrease in the number of pore-capillaries and a corresponding increase in the number of small pores of a spheroidal shape formed in the process of drawing air into the mixture. Such pores, in addition to reducing the thermal conductivity of concrete, working as arch arches, provide an increase in the strength of cement stone and polystyrene concrete.

Composite low-clinker (with clinker content up to 40%), or clinker-free binders based on activated blast furnace or electrothermophosphoric, or converter granular slag with a specific surface of 2800-3500 g / cm ² , or bauxite sludge, characterized by normal density of cement paste 19, were used as a binder. -24% and the coefficient of thermal conductivity of the cement stone (λ _o ) = 0.39-0.50 W / (m • ^o C)).

Examples of binder compositions are given in table. 1, where CC is cement clinker, DGS is blast furnace slag, KGS is converter slag, BS is bauxite sludge, G is gypsum, C-3 is a superplasticizer based on the sodium salt of the condensation product of β-naphthalene sulfonic acid with formaldehyde, powder according to TU 6-36 -0204229-625; R ₂₈ is the compressive strength at the age of 28 days, determined according to GOST 310.4; λ _o - coefficient of thermal conductivity of cement stone in the dry state according to GOST 7076; НГЦТ - normal density of cement paste in accordance with GOST 310.3.

For the mixture used polystyrene gravel fraction 0-10 mm bulk density 10-30 kg / m ³ according to TU 5712-161-00284807-96; air-entraining additive - SDO according to TU 13-0281078-02-93 calculated on the dry matter; Lignopan-B water-reducing additive in the form of a 30% aqueous solution (commercial product) according to TU 2601-002-2012-7879-96, which consists of fractionated lignosulfonates of inorganic salts such as sulfates and carbonates, cellulose ethers, copolymers of acrylic series.

 The mixture was prepared as follows.

 At first, polystyrene-foamed gravel dosed by volume was fed into the mixer and mixed for 30 s with 1/3 of mixing water. Then the binder was loaded and the mixture was stirred for 20-30 s, after which the rest of the water and lignopane-B solution were poured, then the SDO solution was loaded and mixed until a fused porous structure was obtained. The total duration of the preparation of concrete mix is at least 4 minutes.

 Examples of polystyrene concrete mixes using various fractional composition of polystyrene foam gravel and the results of physico-mechanical and thermotechnical testing of concrete are given in table. 2, 3 and 4. In compositions 1, 3, 5, 7, 9, 11, 13, 15, gravel of the following grain composition was used, vol.%: Fraction 5-10 mm 30%; 2.5-5 mm 20%; 1.2-2.5 mm 30%; 0-1.25 mm 20%. In the compositions 2, 4, 6, 8, 10, 12, 14, 16: fraction of 5-10 mm 15%; 2.5-5 mm 20%; 1.25-2.5 mm 35%; 0-1.25 mm 30%. In compositions 1-4, a binder of composition 1 was used (table. 1); 5-8 - binder composition 2, 9-10 - binder composition 3, 13-16 - Portland cement ПЦ 400 Д15.

The density (ρ) of polystyrene concrete was determined according to GOST 12730.1, strength (R ₂₈ ) according to GOST 10180, heat conductivity coefficient (λ _o ) according to GOST 7076, frost resistance coefficient after 50 freezing cycles (K _mrz ⁵⁰ ) - according to GOST 10060.1, water resistance (coefficient softening K _p equal to the ratio of concrete strength at natural humidity to strength in a water-saturated state) - according to GOST 27677.

Data analysis table. 1, 2, 3 shows that the use of composite binders of the proposed compositions in combination with polystyrene gravel of the proposed fractional composition and the use of lignopane-B as a water-reducing additive ensures the production of heat-insulating polystyrene concrete grades of density D200-D500 with a compressive strength of 0.19-2, 3 MPa, with a coefficient of thermal conductivity λ _o = 0,044-0,010 W / (m • ^o C) while ensuring the required indicators of concrete durability (water resistance and frost resistance). In this case, the thermal conductivity coefficient of polystyrene concrete of the proposed composition is reduced by 15-28% compared with polystyrene concrete of known compositions.

Sources of information
1. RF patent N 2120429, cl. C 04 B 38/08, BI N 29, 10.20.98.

 2. GOST R 51263-99. Polystyrene concrete. Technical conditions Gosstroy of Russia. M., 1999 (prototype).

Claims (1)

A mixture for the manufacture of heat-insulating products, including a composite binder based on activated technogenic waste of aluminosilicate composition, polystyrene foam aggregate, air-entraining and water-reducing additives and water, characterized in that the binder contains blast-furnace or electrothermophosphoric granular slag with a specific surface area of 2800 - 3500 cm ² / g, and / or bauxite sludge, and / or converter slag, ground to a specific surface of 3200 - 3500 cm ² / g, with the following ratio binder constituents, wt.%:
Indicated waste - 55 - 95
Cement Clinker - 0 - 40
Gypsum - 0 - 5
Sodium Chloride - 0 - 5
Powdered S-3 - 0 - 3
the mixture as a filler contains polystyrene gravel fraction 0-10 mm, bulk density 10-30 kg / m ^{3 the} following grain composition, vol.%:
Fractions
5 - 10 mm - 15 - 30
2.5 - 5 mm - 20 - 35
1.25 - 2.5 mm - 30 - 40
0 - 1.25 mm - 20 - 30
and as a water-reducing additive - lignopane -B in the following ratio of the components of the mixture, wt.%:
Binder - 53.57 - 71.56
Placeholder - 1.73 - 11.37
Air entraining additive - 0.06 - 0.31
Water-reducing additive - 0.37 - 0.68
Water - Other

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