RU2515664C2 - Heat-insulating constructive polystyrene concrete - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to construction materials, in particular to polystyrene concretes, used in heat-preserving protective structures of buildings and constructions. Heat-insulating constructive polystyrene concrete with density 225-350 kg/m³, is obtained from mixture, which contains Portland cement, water, complex air-involving and plasticising additive of multifunctional action, which represents balanced mixture in dry or liquid form, consisting of air-involving additive PO-01B based on products of oxidation of food industry wastes and plasticiser of polycarboxilate type or sulfonated product of polycondensation of melamine with formaldehyde with number of links in molecular chain equal 18-27 with weigh ratio: air-involving additive:plasticiser, equal 1:(0.25-0.5), and specific consumption of said complex additive 0.06-0.15 wt % of Portland cement weight, polystyrene foamed granulated (PFG) with volume content in polystyrene concrete - φ in the range 0.40-0.60, obtained after triple foaming of initial polystyrene beads with coarseness 0.7-1.0 mm and characterised by complex dimensionless index of PFG quality - n in the range 1.5-1.75, whose values are determined in the process of designing polystyrene concrete composition by formula:

where K₁ and K₂ are coefficients, reflecting peculiarities of technology of PFG obtaining, values of which are respectively in the range1.1-1.3 and 8.0-10.8; d_b is the average diameter of initial polystyrene beads, mm; d_av is average weighted diameter of PFG granules, mm; $${\rho }_{PFG}^b$$

and ρ_PFG are bulk and average densities of PFG granules, kg/m³.

EFFECT: creation of heat-insulating constructive polystyrene concrete with density 225-350 kg/m³ with optimal properties: increased strength and heat-insulating properties.

3 ex, 1 tbl

Description

The invention relates to building materials, in particular to polystyrene concrete with a density of 225-350 kg / m ³ used in heat-saving building envelopes of buildings and structures.

Polystyrene concrete is known (GOST R 51263-99, developed by the All-Russian Research Institute of Iron Reinforced Concrete), consisting of polystyrene foam aggregate (granular expanded polystyrene - PVG), Portland cement or slag Portland cement, additives and water.

In this GOST, the characteristics of PVG and the parameters of polystyrene concrete are normalized in terms of density and strength in wide ranges, which are not clearly linked to each other, which does not guarantee the obtaining of optimized indicators of material quality (increased strength values at lower grades in density).

The closest in technical essence of the proposed material is structural and heat-insulating environmentally friendly polystyrene concrete (RF patent No. 2230717), which is adopted as a prototype.

According to the specified patent, polystyrene concrete is made from a mixture including (in% by weight): mineral binder (Portland cement or slag Portland cement) - 49 ÷ 73.5, polystyrene foam aggregate (PVG) with a bulk density of 5-20 kg / m ³ - 1.2 ÷ 12 , a complex additive - 0.75 ÷ 1.50 and water (the rest).

At the same time, a mineral binder from Portlandcent or slag Portland cement may contain a mineral-polymer additive (up to 5%) and finely ground slag (up to 55%). The complex additive includes air-entraining (15-100%), plasticizing (0.35%) additives and hardening accelerator (0-50%).

An air-entraining additive contains saponified wood resin or neutralized air-entraining resin in a solid or liquid state in an amount of 0.2-0.5% by weight of a binder or hostapur in an amount of 0.005-0.0175% by weight of a binder, as well as an additive from a group of a mixture of sodium or triethanolamine salts of synthetic fatty acid monoethanolamide sulfates of fraction C ₉ -C ₁₄ , or a mixture of sodium or triethanolamine salts of alkyl sulfuric acids of fraction C ₁₀ -C ₁₆ , or a mixture of sodium or triethanolamine salts of primary fatty alcohol alkyl sulfates fractions of C ₁₀ -C ₁₆ fractions, or a mixture of polyoxyethylated nonylphenols with the number of hydroxyethylene groups from 3 to 18, or a mixture of sodium salts of nonylphenyl polyoxyethylene acetic acids with a content of oxyethylene groups from 5 to 15, or their binary or ternary mixtures in the ratio 1: (0.1 -1) or 1: 1: 1, respectively.

The plasticizing additive contains modified lignosulfonates in an amount of 0.15-0.3% by weight of a binder or chemical polycondensation products of aromatic sulfonated hydrocarbons based on naphthalene, melamine or waste from their production in an amount of 0.3-0.5% by weight of a binder.

The hardening accelerator contains a water-soluble salt - sulfate or chloride of an alkali or alkaline earth metal in an amount of 0.5-1% by weight of the binder.

The production of PVG is carried out by foaming according to one or multi-stage technology at a temperature of 60-105 ° C.

The prototype has the following disadvantages:

- the composition of polystyrene concrete when using PVG with a bulk density of a wide range of 5-20 kg / m ^{2 is} not related to the average granule size of the aggregate and its volumetric content (concentration) in polystyrene concrete;

- since the quality of PVG and the associated indicators of polystyrene concrete is affected by a set of characteristics, in particular, the initial granule size of polystyrene beads, the weighted average size (diameter), bulk and average density of the obtained granules, as well as the features of the technology and equipment used to produce aggregate, this probably should be reflected in a complex indicator that is not given;

- the use of slag Portland cement or additives of finely ground slag, although it contributes to a certain decrease in the thermal conductivity of polystyrene concrete, however, it does not allow to obtain increased and stable material strength indicators for a given density;

- the use of air-entraining additives such as saponified or neutralized wood resin or hostapur and plasticizing additives based on lignosulfonates does not provide polystyrene concrete with a stable, finely porous structure, and the use of additives of hardening accelerators based on sulfates or chlorides of alkali or alkaline earth metals worsens working conditions in the manufacture of products from polystyrene concrete and reduces the protective properties of polystyrene concrete in products reinforced with steel reinforcement.

The objective of the invention is the creation of heat-insulating structural polystyrene concrete with a density of 225-350 kg / m ³ with optimal properties.

The problem is solved in that the increased strength and heat-insulating properties of polystyrene concrete are ensured by using PVG with a volumetric content in polystyrene concrete of φ in the range 0.40-0.60 obtained after 3-fold foaming of the initial polystyrene beads with a grain size of 0.7-1.0 mm, and characterized by a comprehensive dimensionless quality index of PVG - n in the range of 1.5-1.75, the values of which are determined when designing the composition of polystyrene concrete according to the formula

$$n=\mathrm{1,5}+{\mathrm{TO}}_{\mathrm{one}}\sqrt{\frac{{\mathrm{TO}}_2{d}_b{\rho }_{P\mathrm{AT}G}^n}{d_{\mathrm{from}R}{\rho }_{P\mathrm{AT}G}^{}}-\mathrm{one}},$$

- насыпная и ρ_ПВГ - средняя плотности гранул ПВГ, кг/м³.where K ₁ and K ₂ are coefficients reflecting the features of the technology for producing PVG, the values of which are respectively in the range of 1.1-1.3 and 8.0-10.8; d _b - the average diameter of the original polystyrene beads, mm; d _cf - the weighted average diameter of the granules of PVG, mm; $${\rho }_{P\mathrm{AT}G}^n$$

- bulk and ρ _PVG - the average density of the granules of PVG, kg / m ³ .

In this case, a complex air-entraining and modifying additive CVMD of multifunctional action is used, having the effect of air entrainment and plasticization of the polystyrene concrete mixture, which is a homogeneous harmoniously balanced mixture in dry or liquid form, consisting of an air-entraining additive based on the products of oxidation of food industry waste products in the form of sodium salts of organic acid alkyl sulfates fractions C ₉ -C ₁₂ and polycarboxylate type plasticizer or sulfonated product floor the condensation of melamine with formaldehyde with a number of units in the molecular chain of 18-27 with a mass ratio of components of an air-entraining additive: plasticizer equal to 1: 0.3, with a specific consumption of a complex additive of 0.12 wt.% by active substance based on the weight of Portland cement.

Examples of additives that can be used as components of KVMD are air-entraining additive PO-01B, plasticizer GLENIUM ACE430, plasticizer F-10. GLENIUM ACE430 is a polycarboxylate type plasticizer, F-10 plasticizer is a polycondensation product of sulfonated melamine with formaldehyde.

The use of a comprehensive quality index of PVG - n and its volumetric content in polystyrene concrete - φ allows us to evaluate and optimize the characteristics of the material, and the use of exclusively Portland cement for polystyrene concrete instead of slag Portland cement and granulated slag additives, instead of additives according to the prototype ensures the stability of the structure of the polystyrene concrete mixture and obtaining elevated and optimized indicators of polystyrene concrete in strength for a given density of the material and helps to reduce its character teristics of density and thermal conductivity, ceteris paribus. In addition, the use of additives such as KVMD, with the properties of accelerating the hardening of concrete, eliminates the use of special additives-accelerators.

The proposed calculation method for determining the complex quality index of PVG - “n” allows to obtain material with reduced thermal conductivity with a given strength while reducing the complexity of the design and selection of the composition of polystyrene concrete in the factory.

The problem is solved as follows.

Example 1

.For the manufacture of polystyrene concrete grade average density D300 used PVG obtained by foaming polystyrene beads with an initial grain size d _b = 0.77 mm As a result of 3-fold foaming, PVG was obtained with a weighted average granule size d _cp = 3.81 mm, average PVG granule density ρ _PVG = 16.3 kg / m ³ and bulk density $${\rho }_{P\mathrm{AT}G}^n=8.65\mathrm{to}g/m^3$$

.

With average values of K ₁ = 0.5 (1.1 + 1.3) = 1.2 and K ₂ = 0.5 (8.0 + 10.8) = 9.4, the complex PVG quality indicator will be equal to

.

.

The consumption of materials per 1 m ³ polystyrene concrete was adopted:

- Portland cement activity R _c = 40 MPa C = 244 kg;

- water - 116 l;

- PVG - 0.8 m ³ (at a volume concentration of polystyrene concrete φ = 0.45);

- pore-forming additives PO-01B - 0.02 (2%) by weight of cement.

Cement-water ratio C / B =: 244: 116 = 2.1.

Without the use of plasticizer additives, polystyrene concrete with a density ρ _PSB = 287 kg / m ³ (grade for average density D300) and strength at 28 days of age R _PSB = 0.93 MPa with dry heat conductivity λ _o = 0.082 W / (m ° C). With a coefficient of variation of polystyrene concrete in strength V _p = 12%, the achieved strength corresponds to class B0.75.

Example 2

The use of the GLENIUM ACE430 plasticizing additive at a dosage of 0.07% by weight of Portland cement with the same workability of the polystyrene concrete mixture (as with the mixture without plasticizer) made it possible to reduce the water consumption to 104 l / m ³ .

At the same C / B = 2.1, cement consumption was C = 2.1 · 104≈218 kg / m ³ .

At a PVG concentration of φ = 0.55 (PVG consumption - 1.0 m ³ / m ³ ) and the use of Portland cement with activity R _C = 50 MPa, polystyrene concrete with a density ρ _PSB = 259 kg / m ³ (grade for average density D250) s was obtained the same strength R _PSB = 0.93 MPa (class B0.75) having thermal conductivity in the dry state λ _o = 0.072 W / (m · ° C).

Example 3

With the combined use of the pore-forming and plasticizing additives PO-01B and F-10 at dosages of 0.02% and 0.07% by weight of cement, ceteris paribus, it was possible to reduce the consumption of PVG from 1.0 m ³ / m ³ to 0.8 m ³ / m ³ while reducing thermal conductivity by 7.5% and maintaining the physico-chemical characteristics of polystyrene concrete.

Other examples of specific implementation of the proposed technical solutions are shown in table 1.

The implementation of the claimed thermal insulation and structural polystyrene allows (compared with the prototype) for a given class of material strength to reduce its average density by 1 step and thermal conductivity by 12-24%.

Information sources

1. GOST P 51263-99. Polystyrene concrete. Technical conditions

2. Patent No. 2230717, cl. C1.04B 38/08, 38/10.

Table 1 PVG and thermal insulation and structural polystyrene concrete indicators №№ pp The name of indicators Units rev. Indicator values one 2 3 four 5 6 7 8 9 (prototype) (outrageous values) I. Parameters of PVG one. The diameter of the original polystyrene beads, d _b mm not standardized 0.7-1.0 0.7-1.0 0.7-1.0 0.7-1.0 0.5 1.3 1.3 2. The number (ratio) of foaming time not less than 1 3 3 3 3 3 2 four 3. The weighted average diameter of the granules, d _cf mm 3.7-4.1 3,5-6,0 3,5-6,0 3,5-6,0 3,5-6,0 2,5 5.2 7.5 four. The average density of the granules, ρ _PVG kg / m ³ not standardized 12-16 12-16 12-16 12-16 21 32 eleven 5.

Bulk density, $${\rho }_{P\mathrm{FROM}B}^n$$

kg / m ³ 5-20 7-10 7-10 7-10 7-10 13,2 12.0 10.5 6. Technological factors: K ₁ - not standardized 1.1-1.3 1.1-1.3 1.1-1.3 1.1-1.3 1,0 1.4 1,5 K ₂ - 8.0-10.8 8.0-10.8 8.0-10.8 8.0-10.8 7.0 11.6 14.9 7. Comprehensive Quality Score, n not standardized 1.5-1.75 1.5-1.75 1.5-1.75 1.5-1.75 2.1 1.9 2,5 8. PVG concentration in polystyrene concrete, φ share from 1 not standardized 0.4-0.6 0.4-0.6 0.4-0.6 0.4-0.6 0.38 0.39 0.35 II. Materials for polystyrene concrete 9. Astringent HRC, including with the addition of gravel slag, or ShPC HRC HRC HRC HRC HRC HRC HRC 10. Foaming Additive LMS or START PO-01B PO-01B PO-01B eleven. Plasticizing additive C-3 or Lignopan F-10 Glenium ACE 430 - GLENIUM ACE 430 12. Additive - hardening accelerator Na ₂ SO ₄ or CaCl ₂ - - - - - - - III. Physico-mechanical properties of polystyrene concrete 13. Medium Density Grade D (kg / m ³ ) 300 350 225 250 300 350 250 250 300 fourteen. Compressive strength MPa 0.72 0.91 0.62 0.93 0.93 1.42 0.46 0.44 0.65 fifteen. Strength class B B0.5 B0.75 B0.5 B0.75 B0.75 B1.0 B0.35 B0.35 B0.5 16. Dry Conductivity W / (m ° C) 0,085 0,095 0,068 0,072 0,084 0,095 0,072 0,072 0,084 Note: PC - Portland cement, ШПЦ - slag Portland cement.

Claims (1)

Heat-insulating and structural polystyrene concrete with a density of 225-350 kg / m ³ obtained from a mixture of Portland cement, polystyrene foam granular type PVG, water, air-entraining and plasticizing additives, characterized in that they use PVG with a volumetric content in polystyrene concrete - φ in the range 0.40- 0.60 obtained after 3-fold foaming of the initial polystyrene beads with a particle size of 0.7-1.0 mm and characterized by a complex dimensionless PVG quality indicator - n in the range of 1.5-1.75, the values of which are determined during the project tion polystyrene composition according to the formula

,
where K ₁ and K ₂ are coefficients reflecting the features of the technology for producing PVG, the values of which are respectively in the range 1.1-1.3 and 8.0-10.8: d _b is the average diameter of the initial polystyrene beads, mm; d _cf - the weighted average diameter of the granules of PVG, mm; $${\rho }_{P\mathrm{AT}G}^n$$

and ρ _PVG is the bulk and average density of PVG granules, kg / m ³ , while a complex air-entraining and plasticizing additive of multifunctional action is used as an air-entraining and plasticizing additive, which is a uniform harmoniously balanced mixture in dry or liquid form, consisting of PO air-entraining additive -01B based on oxidation products of food industry waste and a polycarboxylate type plasticizer or a sulfonated polycondensation product of melamine with formaldehyde m with the number of units in the molecular chain 18-27 with a mass ratio of the components of the air-entraining additive: plasticizer equal to 1: (0.25-0.5), and the specific consumption of the complex additive 0.06-0.15 wt.% by active substance by weight of portland cement.