Method of concrete mixture preparation
SUBSTANCE: method of preparing the concrete mixture, consisting in mixing of cement, aggregates, water, and aqueous suspension of complex modifier of the following composition, wt %: silica fume 40-70; chemical additives 2-10; water - the rest, which is dried prior to mixing in the air stream to obtain powder consisting of granules, according to the invention, the aqueous suspension of complex modifier before mixing is subject to drying under the influence of continuous electromagnetic field of ultra-high frequency of 400-1000 MHz from microwave oscillators and heated air stream of microwave oscillator cooling to obtain powder with grains of size up to 500 microns and moisture of 9-12%; then the dried powdered complex modifier and cement are subjected to dispersion and disaggregation via exposure to pulsed electromagnetic field of ultra-high frequency of 1000-3000 MHz lasting 1-1.5 seconds, till the obtention of ultrafine powder of complex modifier with size of 60-100 nm, moisture of 1-8% and cement of size 0.1-5 microns, after that they are mixed, ground together and activated, form the disaggregated and activated mixture of cement and complex modifier, which is mixed with filler and water, concrete mixture is obtained; this mixture is subjected to the influence of powerful pulsed electromagnetic field of ultra-high frequency of 400-1000 MHz with duration of 1100÷nanoseconds.
EFFECT: increase of strength of concrete mixture.
The invention relates to methods for preparation of concrete mixtures with the addition of microsilica with chemical additives.
Known method of preparing a concrete mix with the introduction of its cement, aggregates, water and microsilica with chemical additives in the form of a single pasty product "pulp Alikram" [Woomin V.N., Alferov F.A., Lozovsky M.A. and other New additives in concrete technology - Pulp Alikram, Concrete and reinforced concrete, No. 2, 1990, p.40-41].
The disadvantages of the method are the tendency of the pulp to stratification, which requires periodic mixing during storage, exposure of the pulp to freezing at low temperatures, as well as the need for additional technological supply of superplasticizer and other additives. The plasticity of the concrete mixtures with the addition of such a paste-like product with time (15-20 min after preparation) drops significantly.
Known method of preparing a concrete mixture comprising mixing cement, aggregates, water and the aqueous suspension of the complex modifier containing silica fume and chemical additives, aqueous suspension of the complex modifier of the following composition, wt.%: fume 40-70, chemical additives 2-10, the rest is water, before mixing is subjected to drying in an air stream at 160-250°C to obtain a powder consisting of granules with a size of 500 μm and humidity 1-8%, the minimum time of mixing cement, aggregates, water and complex powder modifier is 3 min [RF Patent №2095327, C04B 28/00, publ. 10.11.1997, IB No. 31. Authors: Kaprielov S. and others, "Method of preparation of concrete mixtures"].
The disadvantage is not a high intensity strength and durability of concrete mixture to compression.
As noted by the authors, the use of integrated powder modifier concrete with a grain size of more than 500 μm (sample No. 8, table 1), while maintaining the ductility of concrete mixes after 120 min, leads to a decrease of concrete strength by 19% (7, table 2), which is obviously related to the insufficient degree of disaggregation is relatively large particles modifier.
It is known that, like all pozzolanic materials, silica fume reacts with calcium hydroxide Ca(OH)2released during the hydration of Portland cement in the formation of cementitious compounds. Very high purity and fineness of silica fume contributes to a more effective and rapid response. With proper dispersion thousands reactive spherical microparticles surround every grain of cement, sealing grout, filling the void solid hydration products and improving adhesion with placeholders.
In addition, in the process of mixing cement with water is prasouda flocculi - fine particles of cement are grouped into larger clumps.
Pore volume in floccular though quite large, but filled his water is still not enough to ensure full hydration of the adjacent grains of cement. Water in floccular fixed. The inflow from outside or outside practically stops. The situation is aggravated and what products started cement hydration even more clog internal channels.
In natural terms, this process results in the fact that the smallest and therefore the most reactive particles of cement, which were to provide fast curing huddle together in clumps - flocculi. They react with water mostly only on their outer surface. Inside the water reserves are being rapidly depleted, and the strength potential of the cement is tightly stored for a few years, or even decades, until the atmospheric moisture will not penetrate deep into these flocs.
If you look under a microscope, the grain structure of the cement particles, it can clearly be seen that he was being consolidated in the aquatic environment. Even it is rapid hardening cements with a predominance of particles less than 20 microns in the aquatic environment are aggregated into larger clumps - flocculi. The addition of completepicture S-3 is not completely removes this problem.
This method is selected in the image quality is as prototype.
The technical result of the proposed method is to increase the strength of the concrete mixture.
The technical result is achieved in that in the method of preparation of the concrete mixture, which consists in mixing cement, aggregates, water and the aqueous suspension of the complex modifier of the following composition, wt.%: fume 40-70; chemical additives 2-10; water - the rest, which, prior to mixing is subjected to drying in an air stream to obtain a powder consisting of granules according to the invention, the aqueous suspension of the complex modifier before mixing is subjected to drying by exposure to continuous electromagnetic field of ultrahigh frequency 400-1000 MHz microwave generators and hot air flow cooling of the microwave generators to obtain a powder with granules of a size of up to 500 microns and a moisture content of 9-12%, and then dried complex powder modifier and the cement is subjected to dispersion and disaggregation by exposure to a pulsed electromagnetic field ultra high frequency 1000-3000 MHz duration 1-1,5 seconds, to obtain ultrafine powder of the complex modifier size of 60-100 nm humidity 1-8% and cement in the range of 0.1-5 μm, after which they mix, grind together and activate, form of disaggregated and activated mixture of cement and is integral modifier, which is mixed with aggregate and water, receive the concrete mixture, which is affected by high-power pulsed electromagnetic field ultra high frequency 400-1000 MHz with a duration of 1÷100 nanoseconds.
Before mixing the concrete mix aqueous suspension of the complex modifier is subjected to drying by exposure to continuous electromagnetic field of ultrahigh frequency 915 MHz microwave generator and heated air flow cooling of the microwave generators to obtain a powder with granules of a size of up to 500 microns and a moisture content of 9-12%, this reduces energy needs and the duration of the technological process as heating and drying of the suspension takes place in the whole volume at once. Then dried complex powder modifier and the cement is subjected to dispersion and disaggregation by exposure to a pulsed electromagnetic field ultra high frequency 2450 MHz with a duration of 1-1,5 seconds, to obtain ultrafine powder of the complex modifier size of 60-100 nm humidity 1-8% and cement in the range of 0.1-5 μm. The pulse mode of the microwave generator provides a low energy consumption of the process.
Concrete strength will be increased due to the fineness (nanodispersed and ultradispersed) of the alloy particles and cement. The smaller the particles are, the faster and effective is e cement gains strength, forming a monolithic cement stone.
The mixing of the alloy particles and cement, their joint grinding and mechanical activation increases the activity of the particles in the interaction with water and other fillers. Received disaggregated and activated mixture of cement and complex modifier is mixed with aggregate and water, receive the concrete mixture, which is affected by high-power pulsed electromagnetic field ultra high frequency 400-1000 MHz with a duration of 1÷100 nanoseconds. This allows you to destroy the formed clots, which are obtained by the interaction of cement and water, modifier and water, cement modifier and water, which will speed up the process of curing and increase the strength of the concrete mixtures in compression.
An example implementation of the method of preparation of the concrete mixture.
Materials for preparation of complex modifier: microsilica (MK) brand MK-85 on THE 7-249533-90 "condensed silica Fume. Technical conditions"; a superplasticizer (SP) type C-3 on the basis of the sodium salt of the condensation product of naphthalenesulfonate and formaldehyde, corresponding to THE 6-36-0204229-625-90 "Plasticizer S-3"; nitrilotrimethylphosphonic acid (NTF), corresponding to THE 6-09-5283-86 "Nitrilotrimethylphosphonic acid. Technical conditions"; sodium nitrite (NN), corresponding to GOST 19906-74 "Nitritfrei technical. Technical conditions"; resin neutralized air (start), corresponding to THE 81-05-75-74. Suspension of complex modifier was subjected to drying by exposure to continuous electromagnetic field of ultrahigh frequency 915 MHz microwave generator and heated air flow cooling of the microwave generators to obtain a powder consisting of granules with a size of 500 microns and a moisture content of 9-12%. Dried complex powder modifier and the cement was subjected to dispersion and disaggregation by exposure to a pulsed electromagnetic field ultra high frequency 2450 MHz with a duration of 1-1,5 seconds, to obtain ultrafine powder of the complex modifier size of 60-100 nm humidity 1-8% and cement in the range of 0.1-5 μm, with further stirring, joint grinding and mechanical activation. Dispersion and joint grinding has led to an increase in interfacial surface section materials. Received disaggregated and activated mixture of cement and complex modifier mixed with aggregate and water, received a concrete mix. To this mixture was affected by high-power pulsed electromagnetic field ultra high frequency 915 MHz with a duration of 1÷100 nanoseconds.
Dispersion is the quality of thermodynamic characteristics of the system, defining Majesty is well the interface. Excess surface energy has a significant impact on the intensity and peculiarities not only chemical but also physical-chemical processes, both at normal and at elevated temperatures.
Characteristic dispersion is the degree of dispersion of S, i.e. the degree of atomization of the substance of the dispersed phase, representing the reciprocal of the particle size d.
The most convenient and common characteristic dispersion of the powdered materials is specific surface area, determined by the ratio of the surface of all particles to their volume or weight.
The value of specific surface area of the complex modifier was determined by the method based on the dependence of permeability of the layer of material from its dispersion. This method is based on measurement of the resistance offered to the air passivemode through a layer of a sealing material of a certain thickness and cross-sectional area.
Studies of the phase composition of the powder material and the determination of the particle size was conducted at the Center for collective use of scientific equipment "Study of physico-chemical properties of substances and materials" (MAC).
The proportion of particles with a size of 60-85 nm in a mixture of powdered inoculant was 70-85%. The average particle size of the modifier was 100 nm. Set the but with a scanning electron microscope JSM-6390A.
Considering the fact that bulk density modifier is 750±50 kg/m3the specific surface of the powder of the complex modifier amounted to 450,000 cm2/g, the specific surface of the powder cement - 36000 cm2/year
The freezing point of the obtained product was determined by visual assessment of the behavior of the material at low temperature: the change of flowability (angle of repose). When exceeding the angle of repose of 20° flowability was recognized as unsatisfactory. Accordingly, we determined the optimal range of humidity of the material, the freezing temperature and, accordingly, the angle of repose associated with relative humidity.
Optimal dispersion of the material was determined by the maximum strength of concrete, which was achieved by mixing the powder-like modifier with other components of the concrete mix for 3 minutes
Concrete mixes were prepared using Portland cement M400 (GOST 10178), quartz sand, with Μr=2,1 (GOST 8736), granite gravel fraction 5-20 mm (GOST 8267). In the method of preparation of the concrete mixture, taken as a prototype, in the mixer for at least 3 min mixed together: cement, aggregates, water and powdered product complex modifier multifunctional actions with a particle size in the range of 500 μm and a relative VL is the possibility 1-8%, which is prepared from the slurry by drying in an air stream at 160-250°C. In the proposed method, the silica fume and himebauch was introduced in the form of powder modifier, which is prepared from a suspension of complex modifier, by drying influencing continuous electromagnetic field of ultrahigh frequency 915 MHz microwave generator and heated air flow cooling of the microwave generators to obtain a powder consisting of granules with a size of 500 microns and a moisture content of 9-12%. Dried complex powder modifier and the cement was subjected to dispersion and disaggregation by exposure to a pulsed electromagnetic field ultra high frequency 2450 MHz with a duration of 1-1,5 seconds, to obtain ultrafine powder of the complex modifier size of 60-100 nm humidity 1-8% and cement in the range of 0.1-5 μm, with further stirring, joint grinding and mechanical activation.
Cement, silica fume and chemical additives belong to the class of imperfect dielectrics and extremely effectively interact with the microwave field. Absorbed by mixtures of microwave power is distributed approximately uniformly over the volume of the aggregated lumps that allows their fast heating. This leads to intense evaporation of water. When this humidity powdery material, the donkey processing, reaches 1-8%. This humidity is necessary to ensure the required conditions for grinding and mechanical activation, long-term storage, as well as to save pozzolanic activity and prevent clumping of the powder particles.
The concrete compositions with modifiers based on prototype and the proposed method was adopted the same, kg/m3:
cement 300; 730 sand; gravel 1120; water 165.
Powder modifier and suspension (slurry) was introduced into the concrete mixture at the rate of 15% microsilica by weight of cement, and water in the composition of the suspension was taken into account in the total amount of mixing water.
Concrete strength was evaluated by testing samples-cubes the size of the edge 10 cm, Tverdovsky under standard conditions.
In table 1, as an example, the results of tests of properties of complex modifier, concrete mixes and concrete, prepared by the proposed method.
It is known that the most active components of concrete is a mixture of cement and water. The speed and depth of hydration of the cement, the conditions of curing of concrete at an early age are critical factors, which affect the rate of curing of concrete, and on its quality.
|The components of the suspension and the influence of modifiers on concrete strength|
|№ p/p||The ratio of the components of the suspension, wt.%||Humidity obtained modifier, %||Freezing point modifier °C||The granule size, microns||The strength of concrete 28 day standards. Chr., MPa|
|The proposed option||The size of granules, nm|
The effect of microwave heating is based on the absorption of electromagnetic energy in dielectrics. Field microwave penetrate to a considerable depth, which depends on material properties. Interacting with matter on an atomic and molecular level, these fields affect the motion of electrons, which leads to the conversion of microwave energy into heat at the same time throughout the volume on the depth of penetration of electromagnetic waves.
Such properties EMF microwave can intensify the strength of the concrete mix by 5-8%.
The table shows the test results of the properties of complex modifier,concrete mixes and concrete. The table shows that the samples No. 5-7, obtained by the proposed method, has a low moisture content and therefore a low freezing point. Efficacy was assessed on the concrete of the same composition.
The proposed method increases the strength of concrete of the same composition in 12-23% in comparison with the prototype.
The method of preparation of the concrete mixture, which consists in mixing cement, aggregates, water and the aqueous suspension of the complex modifier of the following composition, wt.%: fume 40-70; chemical additives 2-10; water - the rest, which, prior to mixing is subjected to drying in an air stream to obtain a powder consisting of granules, characterized in that the aqueous suspension of the complex modifier before mixing is subjected to drying by exposure to continuous electromagnetic field of ultrahigh frequency 400-1000 MHz microwave generators and hot air flow cooling of the microwave generators to obtain a powder with granules of a size of up to 500 microns and a moisture content of 9-12%, and then dried complex powder modifier and the cement is subjected to dispersion and disaggregation by exposure to a pulsed electromagnetic field ultra high frequency 1000-3000 MHz duration 1-1,5 seconds to obtain ultrafine powder of the complex modifier R is Merom 60-100 nm humidity 1-8% and cement in the range of 0.1-5 μm, then mix together ground and activate, form of disaggregated and activated mixture of cement and complex modifier, which is mixed with aggregate and water, receive the concrete mixture, which is affected by high-power pulsed electromagnetic field ultra high frequency 400-1000 MHz with a duration of 1÷100 nanoseconds.
SUBSTANCE: method of tempering moulding mixtures includes mixing dry components and preparing tempering water by passing said water between electrodes while applying an alternating or constant potential difference with rate or strength of current which provides charge saturation density of water that has passed between the electrodes of not less than 825 kC/m3, saturating the tempering water during electrolysis with Fe3+ ions of the electrode until saturation of the water with iron ions reaches 30-35%. Ascorbic solution is first added to said water in amount of 0.1 g/l.
EFFECT: increasing mobility of moulding mixtures without increasing the total amount of tempering water, thereby considerably improving operational characteristics of the finished articles and saving binding materials.
SUBSTANCE: method to prepare an ash-concrete mix, including mixing of ash, portland cement, sand, crushed stone and water, where ash of hydraulic removal is enriched, then the produced ash jointly with portland cement, gypsum and plasticising additive LTSM-2 is ground in a ball mill to the specific surface of 4500-5000 cm2/g, the produced mix is introduced, 2/3 part of the estimated hardening water quantity, sand and quick lime into a dispersing hydrator and exposed to activation for 1-2 min at speed of blades rotation 100-200 rpm, in the concrete mixer they mix crushed limestone and the remaining part of the hardening water for 1-2 min, then the activated mixture from the dispersing hydrator is charged into a concrete mixer, and by final mixing they produce a concrete mix of homogeneous consistence.
EFFECT: cheapening of a mix, faster process of setting and hardening of an ash concrete mix, increased strength and stability of ash concrete properties, expanded area of recycling of anthropogenic origin wastes.
1 ex, 1 tbl
SUBSTANCE: method to manufacture construction materials based on a magnesia binder includes activation of a magnesia binder, modified filler, plasticiser, pigment by the method of mechanical-chemical modification in solid state under condition of joint impact of pressure and shift deformations. Aqueous solution of magnesium chloride (aqueous solution of bischofite) and filler are added to the activated mix. The magnesia binder is caustic magnesite with addition of electric furnace magnesite. The modified filler in the raw mix is a complex silica-alumina filler including SiO2, Al2O3, CaO, MgO, Fe2O3, FeO, SO3 in different combinations and ratios, modified in solid state with oxide or salt of transition metal by the method of mechanical-chemical modification under conditions of joint impact of pressure and shift deformations, and also the raw mix may additionally contain mica and fibres (natural, polymer, metal, glass). The mix is hardened at the temperature of 10-90°C for 1÷14 h, and macromolecular structures of finished goods are exposed to diffusion process of introduction of oil/water emulsion in presence of a surfactant.
EFFECT: improved physical-mechanical characteristics of construction products with lighter weight of structural construction elements, improvement of decorative properties of finished goods.
SUBSTANCE: preparation method consists in that molybdenum scheelite wastes in an amount of 9-10% and an organic substance - crushed corncobs - 7-8% are additionally added to portland cement in an amount of 25-30%, chip 12-15% and sand 15-18% , the rest is water.
EFFECT: increase of the concrete strength and improvement of production of ecologically safe products.
SUBSTANCE: method for making road concrete mix by mixing heated mineral components, bitumen and an additive using oil sludge differs by the fact that as an additive there used is fine-grained powder obtained by intense mixing of the working agent with oil sludge at their ratio of 1.5:1 with addition of water for complete lime slaking, where the working agent is obtained by mixing of the following components, wt %: animal fat 1-3, adsorbent - thermally treated shells 18-22, unslacked lime ground to 10-3÷10-5 m is the rest at bitumen content of 67-84% of the weight of the above additive, mineral components are heated to 70-90°C, mixture of bitumen with the above additive is up to 90-100°C, and mixing of all mixture components is performed at heating of up to 140-170°C.
EFFECT: enlarging the range of road concrete mixes.
4 ex, 1 tbl
SUBSTANCE: invention relates to geopolymer compositions. A dry mixture for a geopolymer binder contains at least one fly ash containing calcium oxide in amount of less than or equal to 15 wt %, at least one gel formation accelerator and at least one hardening accelerator having a composition different from that of said ash. Said dry mixture prepared by mixing with an activator. A geopolymer concrete or mortar composition obtained by mixing said binder with an aggregate. Methods of preparing a concrete or mortar composition using said binder. The invention is developed in subclaims.
EFFECT: reduced microcracking, maintaining ultimate strength after hardening at low temperature.
50 c, 40 ex, 6 tbl, 3 dwg
SUBSTANCE: in the method to manufacture wood concrete items with production of a base on their surface for plastering, providing for preparation and dosing of a hydraulic binder, ground cane stems, water, mixing of components, moulding of items with vibration, hardening, moulding with vibration is carried out so that cane stems cut into sections with length of 4-6 cm are located near the surface of the items, with one end staying in the mix, and with the other one - protruding outside and forming a base for application of plaster.
EFFECT: higher convenience of plaster application onto surface of items.
SUBSTANCE: method to produce construction products from foam concrete includes separate preparation of foam and mortar mixture, their mixing or single-stage preparation of foam mass with subsequent laying into moulds, soaking, removal of formwork, steaming and removal of the product mould. At the same time after laying the foam concrete mass onto full volume into a stiff perforated mould it is closed with a cover, creating a closed volume, and connect to the AC network via plate electrodes arranged on two opposite sides of the mould. The mass is exposed to electric heating with current of industrial frequency 50 Hz with voltage of 50-80 V for 15-20 min. After electric treatment the product is maintained for 40-60 min to remove temperature stress and gain structural strength. Then formwork is removed. After this the product heated to 60°C on the tray arrives for further thermal treatment.
EFFECT: reduced technological process of production with parallel increase of strength and thermal properties of an item.
2 ex, 1 tbl
SUBSTANCE: invention can be used in production of construction materials. Photocatalytic composite material practically free from titanium dioxide contains limestone in amount at least 0.05% by the weight of sodium and calcium titanate in crystalline phases CT2 and/or CT5, characterised by the following diffraction maximums: CT2: (002) d=4.959; (210-202) d=2.890; (013) d=2.762 and (310-122) d-2.138; CT5: (002) d=8.845; (023) d-4.217; (110) d=3.611 and (006) d=2.948. The empirical formula of calcium titanate in phase CT2 is CaTi2O5, and the empirical formula of calcium titanate in phase CT5 is CaTi5O11.
EFFECT: invention makes it possible to increase photocatalytic activity of composite materials without application of titanium dioxide.
18 cl, 8 dwg, 7 ex
SUBSTANCE: in the method to prepare an asphalt-concrete mix by means of mixing of heated mineral components, bitumen and an additive with usage of oil sludge, the additive is a finely dispersed powder, produced intense mixing of a working agent with oil sludge at their ratio of 1.5:1 with addition of water for full lime slaking, treatment of produced product with carbonic acid gas for 10-15 minutes and soaking under tight conditions for 18-30 hr, where the working agent is produced by mixing, wt %: animal fat 1-3, adsorbent produced by pyrolysis of worn car tyres at 850-1100°C with subsequent separation of metal cord and grinding to 10-3÷10-5 m, 18-22, burnt lime ground to 10-3÷10-5 m, balance, with content of bitumen of 66-83% of the mass of the specified additive, mineral components are heated to 70-90°C, the mixture of bitumen with the specified additive - up to 90-100°C, and mixing of all these mixture components is carried out during heating of up to 140-170°C.
EFFECT: improved parameters of an asphalt-concrete mixture by water resistance and water saturation.
1 tbl, 4 ex
SUBSTANCE: composition for producing structural materials, comprising mineral binder, filler, water and nanomaterials, characterised by that the mineral binder is cement M-500 and bentonite clays, the filler is aluminosilicate microspheres (Al2O3) with diameter of 5.0-500 mcm, and as nanomaterials, the composition further includes a microstructure of needle-like wollastonite filler MIVOLL-97, free of natural calcium metal silicate, and fractional microcalcite MICARB "STANDARD"-96 and a foaming agent PB-200, with the following ratio of components, wt %: bentonite clays 2.0-8.0, aluminosilicate microspheres with diameter of 5.0-500.0 mcm 3.0-25.0, MIVOLL-97 - 1.5-5.5, MICARB "STANDARD"-96 - 2.0-8.0, silicon nanostructures AEROSIL - 2.0-5.0, foaming agent PB-200 - 1.0-4.0, water - 3.0-15, cement M-500 - the balance.
EFFECT: obtaining a high-strength composition with improved processing properties structural materials, the present combination of ingredients of the composition is optimal and enhances positive working qualities thereof.
4 ex, 5 dwg
SUBSTANCE: invention relates to special concrete compositions and can be used in the industry of structural materials in producing radiation-proof concrete, including concrete for "dry protection" of a nuclear power plant reactor. The radiation-proof concrete composition contains inorganic binder, serpentinite chips with particle size of 5-20 mm, serpentinite peebles, water, the composition being characterised by that it further contains a superplasticiser, calcium oxide, magnesium oxide, barium oxide or mixtures thereof, with the following ratio of components, wt %: inorganic binder 5.0-20.0; serpentinite chips with particle size of 5-20 mm 31.0-55.0; serpentinite peebles 6.0-30.0; alkali-earth metal oxides 8.9-10.0; superplasticiser 0.1-1.0; water 4.0-8.0.
EFFECT: high quality of concrete as a result of improved workability and reduced demixing when applying the concrete mixture due to reduced water segregation and mortar segregation, as well as faster drying of the concrete.
2 cl, 1 tbl
SUBSTANCE: composite construction material comprising a cement binder, a filler, lignocellulose materials and an additive - a mixture of low molecular polyethylene and urea at the ratio of 1:1, additionally contains a non-ionogenic surfactant polyvinyl pyrrolidone at the following ratio of components, wt %: cement binder 20-30, filler 44-56, non-ionogenic surfactant polyvinyl pyrrolidone 0.5-2, lignocellulose materials 5-12, mixture of low molecular polyethylene and urea at the ratio of 1:1 0.5-3.5, water - up to 100.
EFFECT: development of a composite construction material to manufacture concrete products, making it possible to increase compressing strength, cone slump, tensile strength in bending, elasticity modulus and to reduce water absorption.
SUBSTANCE: invention relates to cement mortar with improved characteristics for formation of structures, which include synthetic fibres, in particular in form of interlacements, for strengthening of building constructions. Mortar includes methylmethacrylate/n-butylacrylate synthetic resin and glass fibres, dispersed in mortar. Invention also relates to method of strengthening of building constructions with application of said mortar. Invention is developed in dependent items of the invention formula.
EFFECT: strengthening of building constructions, increase of their resistance to unmixing.
9 cl, 2 dwg
SUBSTANCE: invention relates to a method of preparing a hardening accelerator composition by reacting a water-soluble calcium compound with a water-soluble silicate compound and a method of preparing a hardening accelerator composition by reacting a calcium compound with a silicon dioxide-containing component in an alkaline medium, in both cases the reaction of the water-soluble calcium compound with the water-soluble silicate compound being carried out in the presence of an aqueous solution which contains a water-soluble comb polymer suitable as a plasticiser for hydraulic binders. The invention also relates to a composition of calcium silicate hydrate and comb polymer, use thereof as a hardening accelerator and for reducing permeability of hardened mixtures.
EFFECT: obtaining a hardening accelerator having plasticiser properties, which is capable of increasing strength and wear resistance.
41 cl, 12 tbl, 3 dwg
SUBSTANCE: inventions relate to protection of substrates against corrosion. Claimed is dispersible redispersible or water-soluble mixture for reinforcing construction materials and protection against corrosion, based on, at least, one water-soluble organic polymer and, at least, one organic silicon compound, which contains, at least, one SiOSi-bond, with content of organic polymer constituting approximately from 40 to 80 wt % counted per the sum of organic polymer and organic silicon compound; and organic silicon compound, which contains, at least, one SiOSi-bond, is based on oligomeric mixture of alkylalkoxysiloxanes, which contains from 50 to 100 wt % of alkylalkoxysiloxanes and has oligomerisation degree mainly from 2 to 20, with oligomer mixture of alkylalkoxysiloxanes satisfying the overall formula I: (R")Si(OR"')xOy (I), where groups R" represent similar or different linear, branched or cyclic alkyl radicals with 1-18 carbon atoms, mainly methyl, ethyl, propyl, hexyl, octyl, hexadecyl; groups R"' are similar or different and represent hydrogen or linear or branched alkyl radical with 1-4 carbon atoms, mainly methyl, ethyl, propyl, and 1,0<x<2,0 and 0,5<y≤1,0, on condition that (2y+x)=3.
EFFECT: creation of substance for protection of materials against corrosion, which can be added to dry construction mixtures both in form of powder and in form of liquid preparation, storage stability, ecological friendliness, and absence of interaction or very insignificant interaction with hydraulically binding components.
18 cl, 4 tbl, 7 ex, 3 dwg
SUBSTANCE: invention relates to method of obtaining cement compositions, holding sagging or holding sagging with high early strength. Method includes mixing hydraulic cement, filling agent, water and sagging-holding additive, which represent dynamic polycarboxilate copolymer. Copolymer contains residues of, at least, the following monomers: A) unsaturated dicarboxylic acid, B) at least, one ethylene-unsaturated alkenyl ether, which has C2-4 oxyalkylene chain with from 1 to 25 links, C) at least, one ethylene-unsaturated alkenyl ether, which has C2-4 oxyalkylene chain with from 26 to 300 links, D) ethylene-unsaturated monomer, which contains part, hydrolysed in cement composition, in which residue of ethylene-unsaturated monomer, when hydrolysed, contains active binding site. Ratio of component A acid monomer to alkenyl ethers of component B and component C(A):(B+C) constitutes from1:2 to 2:1. Ratio of acid monomer of component A to ethylene-unsaturated monomer of component D, which contains hydrolysed part, constitutes from 16:1 to 1:16.
EFFECT: invention makes it possible to preserve placeability of composition for a long period of time and increase compression strength.
30 cl, 5 dwg, 8 tbl, 29 ex
SUBSTANCE: invention relates to compositions of a concrete mixture and can be used in construction when making high-quality prefrabricated concrete or reinforced concrete articles and structures. The concrete mixture contains the following, wt %: portland cement containing more than 16% grains with average diameter of less than 3 mcm, containing grinding intensifier InCem E500 in amount of 0.0365% of the mass of portland cement 15.28-16.49; said with fineness modulus of 2.1 29.67-29.95; crushed stone of the fraction 5-20 48.53-48.64; Sika Viscocrete 20 Gold additive 0.061-0.066; water - the balance.
EFFECT: high strength of concrete aged 10 to 12 hours, which enables to lower the temperature of isothermic ageing of the concrete during steam curing when making prefabricated concrete or reinforced concrete.
1 ex, 2 tbl
SUBSTANCE: claimed invention relates to composition of binding agent based on sulfoaluminous clinker and Portland cement clinker and can be applied in industry of construction materials in production of concrete and building elements from concrete. Composition contains, at least, in wt %, relative to total composition weight: from 1 to 99% of Portland cement clinker or Portland cement and from 99 to 1% of belite-calcium-sulfoaluminous-ferrite clinker (BCSAF), which contains, at least, in wt %, with respect to total weight of BCSAF clinker: from 5 to 30% of phase of calcium aluminoferrite composition, corresponding to general formula C2AxF(1-x), with x in the range from 0.2 to 0.8, from 10 to 35% of phase of calcium sulfoaluminate "yelimite" C4A3S from 40 to 75% of belite (C2S), from 0.01 to 10% of one or several secondary phases, selected from calcium sulfates, sulfates of alkali metals, perovskite, gehlenite, free lime and periclase and/or glass-like phase, and total percent composition of said phases of which is higher or equals 97%. Invention also relates to concretes and building elements from it, obtained with application of claimed composition.
EFFECT: preservation or increase of strength, including early terms of hardening.
15 cl, 4 tbl
SUBSTANCE: invention relates to a cement composition based on belite, sulphoaluminate and calcium ferrite (BSCAF), BCSAF-containing clinker, having the following mineral composition relative to the total mass of the clinker: 5-30%, preferably 10-20%, of a phase based on calcium alumoferrite with general formula C2AxF(1-x), where X varies from 0.2 to 0.8; 10-35% of a phase based on calcium sulphoaluminate; 40-75% belite (C2S); 0.01-10% of one or more auxiliary phases, overall, selected from calcium sulphates, alkali metal sulphates, perovskite, calcium aluminates, gehlenite, free lime and periclase and/or a vitreous phase and alkanolamine, where the alkanolamine has said structural formula and is in amount of 0.01-1 wt %. The invention also relates to a method of producing a cement composition, which involves mixing BCSAF clinker with alkanolamine or adding alkanolamine to ground BCSAF clinker. The invention also relates to a suspension, cement mortar or concrete containing BCSAF and said cement composition. The invention is developed in subclaims.
EFFECT: high strength of BCSAF cement at later stages of hardening, including after 90 days.
10 cl, 3 ex, 3 tbl
SUBSTANCE: granulated composite filler for concrete products of size 0.5-10.0 mm, consisting of core and shell, wherein the core is obtained by granulating the mixture together with diatomite and sodium hydroxide milled up to the specific surface area of 150-250 m2/kg at their weight ratio of 0.70-0.95:0.05-0.30 with bond by aqueous solution of sodium silicate with density of 1.2-1.3 g/cm3 in the amount of 0.1-7.0 wt % of mixture, and shell is formed on the surface of core by its balling with dry dust mixture together with milled quicklime and silicofluoride sodium in a weight ratio of 0.85-0.95:0.05-0.15 with the subsequent hardening up to the strength not less than 0.12 MPa, after the indicated balling the additional spraying of 40% aqueous solution of oxalic aldehyde in the amount of 1.0-8.0 wt % (per 100% substance) of weight of shell components is carried out. Concrete building product is obtained by using the granulated filler indicated above.
EFFECT: decrease of thermal conductivity and water resistance of concrete products when increasing and maintaining the strength characteristics.
2 cl, 1 tbl, 1 ex