The method of obtaining a composite material
(57) Abstract:The invention relates to the construction, and in particular to methods of producing a composite material by hardening of mortar and concrete mixtures. The method includes mixing of the binder and aggregates, fluids and additives with high water-holding capacity, concrete placement and hydration of the concrete. After laying the concrete mix it is kept in air-dry conditions before initial set of concrete strength, then carry out its moisture, and as an additive to use the product cultivation of Bacillus species in sugar-containing aqueous solution. 1 C.p. f-crystals, 1 table. The invention relates to the construction, namely to methods for composite materials formed during the hardening of concrete, mortar mixes.A method of obtaining a composite material (1), based on the mixing of the binder and aggregates, the introduction of fluid mixing, the concrete mixture into the form and the hydration of concrete.However, this is impossible to achieve a high strength because of the high water demand of the concrete mix.The closest to the invention by the technical sunstitute mixing and additives with high water-holding capacity, the concrete placement and hydration of concrete.The known method has the following disadvantages. Use as a component of the concrete mix additives with high water-holding capacity (for example plasticizers, superplasticizers) leads to the next. Because immediately after laying the concrete mix shall exercise its moisturizing, which continue as hardening of the concrete, the hydration and hydrolysis of cement used first water introduced into the concrete mix at the time of its preparation and is located either in the pores or adsorbed on the surface of mineral grains binder and filler; in addition, in the hardening concrete water diffuses from the outside when it is wet. As well as in the preparation of concrete mix into it enter water is much more than required to interact with astringent, hydration water held by the additive remains unused, at least in the early stages of hardening. The consequence of this is that the additive molecules occupy a significant amount, and this leads to the fact that the cement stone has a low density and low strength concrete.The aim of the proposed method is to increase the strength of composition the second material, comprising mixing binder and fillers, the introduction of fluid mixing and additives with high water-holding capacity, the concrete mixture, the moisture of the concrete after placement of concrete mixture it is kept in air-dry conditions before initial set of concrete strength and to dehydration additives with high water-holding capacity, and then carry out its moisture.After laying the concrete mixture are observed following processes. At the first stage of hardening on the hydration and hydrolysis of the cement consumed water solvate shells, which are formed by free (noderivative molecules additives) water entered when the concrete mix. The temperature rise due to exothermic reactions intensifies the removal of excess (as compared to its required for interaction with the cement) of free water. Due to the increase in temperature and energy of thermal motion of water molecules held by the additive, it is the Department with the surface molecules of the additive and of its internal cavities. This water is used for hydration of the cement. This reduces the volume occupied by the molecules of the additive, increases platnostou hydration and hydrolysis of the binder. The consequence is the reduction of the sizes of the formed crystallites increase in the number of generated crystal intergrowths, which also contributes to increasing the strength of the cement stone. When dehydration occurs molecules of the additive, concrete is gaining initial strength. For its further growth should supply water from the outside. This is ensured by moistening the concrete.The method is implemented as follows.Dispense the components of the concrete mix, and then carry out their mixing of injected fluid mixing and additive, continuing stirring; after cooking the resulting mixture was placed in the formwork and kept in air-dry conditions before initial set of concrete strength and to dehydration additives with high water-holding capacity; then the surface of the structure moisturize, providing a constant diffusion of water into the concrete.The effectiveness of the proposed method, in comparison with the known (prototype), was evaluated on the strength of cement-sand mortar test specimens in compression at 28 days after manufacture. Mortar mix was prepared using Portland cement-300, its consumption was 15 who (height 5 cm, diameter 5 cm) by pressing the cement-sand mixture at a pressure of 0.7 MPa. As an additive used the product of the cultivation of microorganisms of Bacillus species in 5% aqueous solution of molasses for 7 days at 25oC (3).The additive was injected in the amount of 0,05; 0,20; 0,35; 0.50 and 0.65 per cent solids by weight of cement. After fabrication, the samples were kept in air-dry conditions (temperature 20oC, relative varnosti 60%) for 6, 10, 12, 18 and 24 h; then they stood up to the test under normal conditions (temperature 20oC, relative humidity 100%). Control samples (prototype) immediately after production before the test was kept in normal conditions.Sample strength in compression was determined on a hydraulic press, model PSA-10 GOST 5802 86. The results are given in the table. 1. The method of obtaining a composite material comprising mixing binder and fillers, the introduction of fluid mixing and additives with high water-holding capacity, the concrete placement, the hydration of concrete, characterized in that after laying the concrete mix it is kept in air-dry conditions before initial set of concrete strength and to dehydration by p. 1, wherein an additive with high water Retentivity use the product cultivation of Bacillus species in sugar-containing aqueous solution.
FIELD: building units, particularly wall blocks made of non-autoclave cellular concrete produced in molds with inner detachable partitions of comb type.
SUBSTANCE: method involves assembling necessary number of partitions in single unit outside mold; lubricating thereof and simultaneously moving all partitions in mold with poured cellular concrete mixture. Device for above method implementation involves suspended perforated table with restricting walls and pressing screw arranged above oil reservoir, which may be temporary immersed in oil reservoir. Gripper includes horizontal frame and lifting members made as vertical console rods located perpendicular to frame and arranged under frame. Connected to lower rod ends are controllable rests to support partitions during their transportation and to release thereof if necessary.
EFFECT: reduced labor inputs and increased block quality.
15 cl, 15 dwg
FIELD: construction industry.
SUBSTANCE: the invention is dealt with the field of construction industry, in particular, with a method of heat treatment of monolithic thin-walled reinforced concrete constructions used for acceleration of solidification of monolithic concrete and reinforced concrete constructions of walls and floors. The technical result is reduction of power inputs and a cycle of heat treatment. The method provides for a heating of the air inside a closed space bounded by warmed up structures of walls and floors. At that indoors they create at least one closed local zone, bounded by a wall made out of soft sheet material, and air is heated beyond the limits of this zone.
EFFECT: the invention ensures reduction of power inputs and a heat treatment cycle duration.
12 cl, 1 tbl, 3 dwg
FIELD: building, particularly underground or underwater structures.
SUBSTANCE: method involves building foundation; heating thereof before pouring concrete mix and performing concreting cast-in-place blocks by pouring concrete mix having different temperature along structure height; vibrating concrete mix; covering structure surfaces not enclosed by form with water-impermeable and heat-insulating material and curing thereof in form up to obtaining necessary concrete strength. Foundation is formed of piles arranged along tunnel wall axes. Foundation is heated up to 5 - 20oC. Concreting of members supported by wall piles is performed by filling form with concrete mix under temperature of 20 - 30oC up to level located at height exceeding height of wall component with 4 m-1 surface modulus by 500 mm. Remaining wall and floor structure parts are filled with reinforced concrete mix under 10 - 20oC temperature. Concrete of outer pile foundation area having 600 - 800 mm height measured from contact line with concrete mix is heated up to obtaining 0.28 - 0.3 R28 concrete strength. Form material and covering material have thermal resistance of 0.2 - 0.3 (m2·deg)/W. Form for forming wall components having 4 m-1 surface modulus are coated starting from bottom by material having thermal resistance of 0.2 - 0.5 (m2·deg)/W to improve warmth-keeping thereof. Height of form to be covered and concreting block height are determined from given formulae.
EFFECT: improved crack-resistance; increased erection rate due to increasing admissible dimensions of blocks to be concreted.
3 dwg, 1 ex
FIELD: construction; method of an electrical curing in winter .
SUBSTANCE: the invention presents a method of an electrical curing in winter conditions and is dealt with construction, namely, with the methods of the winter concreting with use of electrical preheating. The technical result is improved water impermeability and strength of the outer layer of concrete. The method provides for a heating with the help of the electro-heated mats and placement on the surface of the fresh-formed concrete mixture of a protective covering. At that before application of the protective covering a row of notches are made on the surface of the fresh-formed concrete mixture in a random order with following pressing in it a mixture made out of a dried fine-grained material. After it in the capacity of the covering they apply on that outer layer a double vulcanized along the perimeter plastic film the top part of which is solid, and the bottom part is perforated with the area of perforation of 30-70%.
EFFECT: the invention ensures improved water impermeability and increased strength of the outer layer of the concrete.
2 cl, 3 tbl
FIELD: manufacture of building materials and concrete and reinforced concrete structures and articles; silicate and concrete resource saving technologies.
SUBSTANCE: proposed method includes preparation of composite complex binder containing cement, mineral additive, chemical additive C-3, mixing the binder and natural filler, molding, preliminary holding of structures and articles under normal conditions, heat and moisture treatment at temperature of isothermic heating of 85-95°C; used as mineral additive is ash and slag wastes or fly ash in the amount of 20% of cement mass; part of natural filler in the amount of 10-15% is replaced with ash and slag wastes; additive C-3 is used in the amount of 0.35% of cement mass; holding is continued for 1.5-2.0 h and heat and moisture treatment is performed according to specified mode; temperature rise is continued for 3 h; isothermic heating is continued for 9 h and reduction of temperature is continued for 3 h.
EFFECT: utilization of ash and slag wastes; enhanced ecological safety; reduced consumption of cement.
1 tbl, 1 ex
FIELD: building, particularly for concreting cast-in-place and precast reinforced concrete structures along with concrete curing temperature regulation.
SUBSTANCE: method involves laying and compacting concrete mix under continuous concrete mix curing temperature control; heating central concrete layers with heating reinforcement when outer concrete layers are in elasto-plastic state. Heating reinforcement is spaced a distance "a" from surface. The heating is carried out simultaneously with surface heat-shielding. Distance "a" is determined as a=δeq(tav-ts)/(ts-ta), m, where δeq - thickness of conditional equivalent concrete layer corresponding to surface thermal resistance, Rs, m; tav - time-average concrete temperature calculated by estimated time of heating directly in heating area, deg; ts - time-average temperature at concrete surface calculated by estimated heating time, deg; δeq is determined as δeq=Rs·λ·F, m, where Rs is heat resistance of rigging with form Rr including thermal resistance Ra of heat transfer from rigging to ambient air, h·deg/kcal; Rs=Rr+Ra=(δr/( λr·F))+(1/(α·F)), h·deg/kcal, where δr is thickness of rigging, m; λr is rigging heat conductivity factor kcal/(m·h·deg), α is rigging surface heat-transfer coefficient kcal/(m2·h·deg), λ is concrete(reinforced concrete) heat conductivity kcal/(m·h·deg); F=1m2 - rigging surface area for thermal resistance calculation, m2. Amount of heat Q used to heat part of member to be heated having length (height) of 1.0 m and cross-sectional width of 1.0 m is determined from Q=(tav-ts)(m+(τ·λ·F/a), where m is constant equal to 60-180 kcal/deg and τ is calculated heating time, hours. The heating reinforcement is heating wires or pipes adapted for hot water circulation.
EFFECT: reduced temperature stresses and prevention of crack formation during structure concreting, as well as possibility to regulate curing temperature.
4 cl, 1 ex, 4 dwg
FIELD: manufacture of building materials.
SUBSTANCE: invention relates to a process for manufacturing products from heat-resistant concrete mix and can be used for lining of industrial heat assemblies operated at temperature up to 1300°C, in particular for lining of brick firing small trucks. In a process of manufacturing heat-resistant concrete mix including mixing chamotte aggregate and self-degrading ferro-chromic slag (22-26%), said chamotte aggregate employing chamotte fraction 5-10 mm (3-32% of the total mix) and less than 5 mm (30-32%), while after indicated mixing sodium hydroxide in the form of aqueous solution is added to resulting dry mix. Final mix contains 10-13%. In a process of manufacturing products from heat-resistant concrete mix, containing self-degrading ferro-chromic slag and chamotte aggregate including curing operation, manufacture of indicated concrete mix is accomplished as above, after which mix is compacted and curing thereof is carried out as heat treatment according to following regime: raising temperature to 60-70°C for 2.0-2.5 h, ageing at 60-70°C for 14 h, raising temperature to 90-95°C for 1.5-2.0 h, ageing at 90-95°C for 5 h, raising temperature to 110-120°C for 2.0-2.5 h, ageing at 110-120°C for 10 h, and lowering temperature to 50-70°C for 3-4 h.
EFFECT: improved performance characteristics of heat assembly members due to increased strength and heat resistance of concrete.
2 cl, 1 tbl
FIELD: mortars used for manufacture of articles.
SUBSTANCE: method involves obtaining ecologically safe mortar by mixing mineral binder and slags or ashes containing heavy metals and toxicants, said slags or ashes being wastes of heat-electric generating plants, or hydroelectric power stations, or metallurgical or garbage plants; adding water into mixture and providing curing; performing microwave processing of resultant solution by radiation during transportation thereof on fluoroplastic part of pipeline at frequency of 2,450 MHz at radiation intensity of 5-10 kW and temperature of 80 C or microwave processing of resultant solution by radiation in molds or monolith at frequency of 460 or 915 MHz or 2,450 MHz at radiation intensity of 0.7-5 kW, at 100% moisture content and 20 C or 80 C. Curing process is performed at 20 C and 100% moisture content during 48 hours.
EFFECT: increased efficiency in neutralization of heavy metals and dioxins, simplified process for manufacture of mortar and reduced production costs.
6 tbl, 1 ex
FIELD: usage of polymeric powder compositions redispersed in water and designed for promoting setting of chemical products used in building with hydraulic settable binders.
SUBSTANCE: powder composition is prepared on base of a) homopolymers or copolymers of one or several monomers selected from group including vinyl ethers of non-branched or branched alkyl carboxylic acids with 1 - 15 C atoms, ethers of metacrylic acids and ethers of acrylic acid and alcohols with 1 - 15 C atoms, vinyl aromatic compounds, olefins, dienes and vinyl halides; b) one or several protection colloids; c) optionally with use of means preventing caking; d) promoters of setting including one or several compounds selected from group of salts of non-organic or organic acids with alkali or alkali-earth metals except calcium carbonate and magnesium carbonate. Such redispersed powder compositions feature good looseness, redispersing capability and improved resistance against caking. Used in building chemical products modified with powder compositions according to invention such as adhesives for cementing tiles, compositions for applying decorative, leveling and protective coatings, plasters, solutions for uniting and so on feature enhanced cohesion at tensioning when soaked in wet atmosphere.
EFFECT: enhanced looseness, improved resistance of powder compositions against caking, high cohesion at tensioning in wet atmosphere of chemical products modified by such compositions and used in building.
8 cl, 2 tbl
FIELD: molding building materials mainly containing magnesium oxide.
SUBSTANCE: proposed method includes the following stages: mixing of magnesium oxide powder with vegetable or mineral powder at definite ratio; adding water to mixture thus obtained for forming moist powder-like mixture; delivery of moist powder-like mixture to preheated casting mold; then, said moist mixture is heated and molded at temperature of from 80 C to 120 C and pressure of from 100 to 250 kgf/cm2 for quick hardening of mixture, after which product is withdrawn from mold. Specification gives description of version of molding the building materials in frame-shaped casting mold of casting machine.
EFFECT: enhanced strength and refractoriness of material; avoidance of toxic vapor emissions in the course of sintering; low cost of materials manufactured by pressure molding or extrusion.
4 cl, 6 dwg, 1 tbl