379 results about "Air content" patented technology

The invention discloses a high-ductility cement-based composite material for repairing a hydraulic concrete structure. The cement-based composite material is prepared from the following components in parts by mass: 20 to 60 parts of cement, 0 to 80 parts of fly ash, 0 to 80 parts of pulverized slag powder, 5 to 10 parts of light-weight calcium powder, 1 to 5 parts of nanometer SiO2, 25 to 40 parts of a fine aggregate, 20 to 40 parts of water, 0.1 to 1 part of a water reducing agent and 0.5 to 2.5 parts of polyvinyl alcohol fibers. According to the high-ductility cement-based composite material for repairing the hydraulic concrete structure, the air content of a mixture is 7 to 10 percent; at the 28-day age, the uniaxial tensile strain is greater than or equal to 5.0 percent, the cube compressive strength is greater than or equal to 60MPa, the frost resistance is greater than or equal to F500, the sulfate corrosion resistance is greater than or equal to KS300, the chloride ion penetration resistance DRCM is less than or equal to 2.0*10<-12>m<2>/s, and the tensile bonding strength with base structure concrete is greater than or equal to 5.0MPa. Under the condition of not mixing any air-entraining agent, preservative or thickening agent, the high-ductility cement-based composite material for repairing the hydraulic concrete structure provided by the invention has high durability, enhanced capability in synergistically acting with an existing structure and a remarkable repairing and reinforcing effect.

The invention relates to a pumping agent and application thereof, belonging to the field of construction materials. The invention aims to provide the pumping agent and the application thereof. The pumping agent provided by the invention comprises 175-325 parts by weight of polycarboxylic acid water reducing agent, 10-60 parts by weight of retarder, 10-50 parts by weight of water retention agent, 0.1-1.5 parts by weight of air entraining agent and 563.5-804.9 parts by weight of water. The invention also relates to the application of the pumping agent in C15-C70 concrete. The addition amount of the pumping agent accounts for 0.9-2.2 wt% of a cementing material in the concrete. The pumping agent prepared by the invention has the advantages of favorable material adaptability, low addition amount, high water reducing rate, low air content, high concrete strength contribution and the like, mainly solves the problem that the polycarboxylic acid pumping agent is easily subjected to over-addition in practical situations, can effectively prevent the defects of the concrete such as weepage, isolation and the like, and ensures the quality of the concrete.

The invention relates to highly-antifreezing highly-slump retaining self-compacting C40 concrete which comprises the following components by kg/m3: 330 parts of cement, 80 parts of granulated blast-furnace slag, 80 parts of fly ash, 830 parts of natural medium sand with a fineness modulus of 2.3-3.0, 920 parts of stone, 4.9 parts of additives, and 160 parts of mixing water; the additive is a modified air-entraining polycarboxylic water reducer, wherein the mixing amount of an air-entraining agent in the polycarboxylic water reducer RP325 is 0.1%, and the mixing amount of the additive for large-scale production is 1.0% of the total amount of gel materials; the air content in the concrete is 5.0%+/-1.0%; the air-entraining amount in the poured structure from the beginning to the third hour is stabilized within a range of 5.0%+/-1.0%, and the concrete expansion degree in 3 hours is maintained at 600+/-50 mm; the number of antifreezing cycle is not less than 150, and the lowest temperature and the highest temperature in the antifreezing cycle are respectively -18 DEG C and 35 DEG C. The concrete of the invention can meet the concrete performance requirements for a skating rink in Shanghai oriental sports center with respect to high slump retaining performance, self-compacting performance, strength performance, high antifreezing performance, and the like.

The invention relates to fair-faced concrete. The fair-faced concrete is prepared from a binding material, a composite water reducer, water and aggregate, wherein the amount of the binding material in the fair-faced concrete is 380-480kg/m<3>; the binding material comprises the following components in parts by weight: 45-70 parts of cement, 10-30 parts of coal ashes and 20-50 parts of granulated blast-furnace slag; the amount of the composite water reducer accounts for 0.5%-1.1% of the binding material; the composite water reducer comprises a polycarboxylate superplasticizer, a defoamer, an air entraining agent and a tackifier; the amount of water accounts for 0.32-0.45 times of the binding material; and the balance is the aggregate. The invention further relates to an application of the fair-faced concrete in ocean engineering construction. The fair-faced concrete provided by the invention is excellent in chloride ion permeability resistance, smooth in surface, and uniform in color and luster; the sum of the area of air bubbles of which the surface area is greater than 1m<2> is not greater than 6*10<-4>m<2>; the maximal diameter of the air bubbles is not greater than 5mm; the depth is not greater than 5mm; and the fair-faced concrete is low in air content and bleeding rate, and can be used in an ocean environment for a long period of time.

The present invention is expansion designable C50 and C60 high strength steel pipe concrete and its preparation process, and features that the expansion designable high strength steel pipe concrete is prepared with P.O42.5 or P.O52.5 Portland cement, water, sand, crushed stone, flyash, efficient set retarding water reducing and plasticity keeping agent WUT-G and closed concrete high-energy delayed expanding agent in certain weight proportion. The present invention has lowered concrete air content not higher than 1.5 %, reduced abhesion between steel pipe and concrete caused by air adhesion and sustained stable expansion of kernel concrete.

The invention provides a method for measuring pressure water absorption rate of lightweight aggregate concrete, comprising the steps of: evenly mixing concrete and lightweight aggregate; weighing CW g of evenly mixed concrete and lightweight aggregate and placing in a square hole sieve of 4.75mm, sieving out cement slurry, then weighing MW1 g of the sieved out cement slurry; putting the evenly mixed concrete and lightweight aggregate into a container provided with an air content meter, smashing and sealing tightly, then pumping air into the lightweight aggregate concrete by the air content meter for pressurizing until the pressure can not descend; re-weighing certain amount of pressurized CW g of lightweight aggregate concrete and placing in the square hole sieve of 4.75mm, sieving out cement slurry, then weighing MW2 g of the sieved out cement slurry; and calculating the water absorption rate R of the lightweight aggregate concrete by using the formula R=[(MW1-MW2)/CW]*100%. The technical scheme leads the lightweight aggregate to be in a saturate state before pumping, and can not appear thickening and drying of concrete to lose liquidity and plug pump tubes under the state of pumping.

This invention publishes a kind of gas phase chromatography method which can measure the air content and the specific gas in the insulating oil with just once sampling. This invention uses Ar as carrier gas. It also uses the packed column sample entrance. What is more, it has six-way value color-spectrum-switching column, heat transmission detector and the H-fire ionization detector. During the process, Ar is divided into 2 parts. One part will directly go out after it goes through the heat transmission detector's reference arm 6, while the other part will go by steps through the sample entrance 1, the first color spectrum column 2, the six-way value 4, the second color spectrum column or gas lock 3, the heat transmission detector 7, the Ni catalysis CH4 converter 8 with H2, and at last the H fire ionization detector 9 with the air. Then it will go out. During the only one sampling, the invention can meanwhile measure the air content and analyze the accident specific gas in the simple oil. To sum up, it operates easily, needs little work and can decrease the analysis error relatively. So it can do the work of analyzing the sample oil which has low degassing ratio well, as it can satisfactorily separate all the groups.

A freeze-thaw durable, dimensionally stable, geopolymer composition including: cementitious reactive powder including thermally activated aluminosilicate mineral, aluminate cement preferably selected from at least one of calcium sulfoaluminate cement and calcium aluminate cement, and calcium sulfate selected from at least one of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate; alkali metal chemical activator; and a freeze-thaw durability component selected from at least one of air-entraining agent, defoaming agent, and surface active organic polymer; wherein the composition has an air content of about 4% to 20% by volume, more preferably about 4% to 12% by volume, and most preferably about 4% to 8% by volume. The compositions are made from a slurry wherein the water/cementitious reactive powder weight ratio is 0.14 to 0.45:1, preferably 0.16 to 0.35:1, and more preferably 0.18 to 0.25:1. Methods for making the compositions are also disclosed.

An apparatus is disclosed for selectively adjusting the firmness of various surface regions of a mattress, including regions providing lumbar, thoracic, and pelvic support to a user. The mattress comprises a plurality of removable tubes filled with a variety of materials, which tubes are inflatable and deflatable by a compressor operating in accordance with the programming of a user. The user is supported on the mattress by, inter alia, the removable, subsurface, tubing which is pressurized by its hybrid material-air contents.

The invention relates to a method and system for monitoring and adjusting both air content and rheology (e.g., slump, slump flow) properties of a hydratable concrete mix contained within a concrete mixer. The system simultaneously tracks dosage of both rheology-modifying admixture (e.g., polycarboxylate polymer cement dispersant) and air control agent or “ACA” (e.g., air entraining agent) by reference to at least four nominal dose response (“NDR”) curves or profiles, which at least four NDR profiles are based on the respective behaviors of each of the ACA and rheology-modifying agent on air content and rheology.

The invention provides a high-pressure multi-phase jet-flow cutting performance test system and a high-pressure multi-phase jet-flow cutting performance test method. The test system comprises a high-pressure water supply system, a high-pressure air supply system, an air-liquid mixing device, a test platform and a test monitoring system. By utilizing the high-pressure water supply system, the high-pressure air supply system and the air-liquid mixing device, a high-pressure water jet flow or a high-pressure air-liquid two-phase jet flow can be formed, and the pressure and air content of the jet flow can be controlled; by utilizing the test platform and the test monitoring system, the impact force and the erosion damage capacity of the high-pressure jet flow can be tested. By utilizing the high-pressure multi-phase jet-flow cutting performance test system, the high-pressure water jet flow or air-liquid two-phase jet flow impact test of parameters including different pressure, air contents, spray nozzle diameter, target distance and the like under a submergence or non-submergence condition can be carried out, important significance for analyzing a relation between various jet-flow erosion rock breaking properties and characteristic parameters and optimizing a hydraulic slot unloading anti-reflection technology can be realized; moreover, the high-pressure multi-phase jet-flow cutting performance test system is high in practicability, simple in structure, convenient to operate, safe and reliable.

The invention discloses a premixed mortar additive, and a preparation technology and an applying method thereof. The premixed additive comprises a mixture A and a mixture B, and the mixture A comprises a thickener, an air entraining agent, a foam stabilizer, a water reducer and water; the mixture B comprises, by weight, a retarder and water; the thickener comprises at least one of welan gum, a polyacrylate copolymer emulsion, starch and carboxymethyl cellulose; the air entraining agent comprises one of AE-2, fatty acid sodium sulfate and calcium lignosulfonate; the foam stabilizer includes one of cocoamido propyl hydroxy sulfobetaine (CHSB) and a composite foam stabilizer formed by polyvinyl alcohol and calcium stearate; the water reducer is selected from a polycarboxylic high performance water reducer; and the retarder comprises at least two of sodium gluconate, white sugar and sodium hexametaphosphate. The premixed mortar additive has the advantages of improvement of the workability and the water retention rate of a mortar, increase of the tensile bond strength, increase of the air content, and easiness in realization of the control of the opening time.

The invention relates to a low air content concrete polycarboxylic acid water reducer and a preparation method thereof. The water reducer is a polymer formed by random copolymerization of A, B and C monomers and has an average molecular weight of 10000-30000, wherein structures of the monomer A, B and C are respectively shown as the following formula (I), (II) and (III), and the meaning of each symbol involved in the formulas can be seen in the specification. The preparation method provided in the invention takes polyoxyethylene and polyoxypropylene ether with a molecular weight of 900-4000 as polymerization monomers to perform random free radical copolymerization in an aqueous solution system. Due to the introduction of perfluoroalkyl phosphate acrylate to a side chain, the air-entraining defoaming function of the water reducer can be improved, and at the same time, the distribution density of main and side chains tends to be more reasonable, so that the water-reducing rate, cement adaptability and slump retention of the water reducer can be improved. In addition, the preparation method involved in the invention has a simple process and less pollution, and can significantly improve the production efficiency and production benefits.

Concrete compositions including a binder, water, a fine aggregate, a coarse aggregate and an admixture are provided. The binder is formed with a blast-furnace slag composition including 100 mass parts of a mixture of 80-95 mass % of blast-furnace slag fine particles with fineness 3000-13000 cm²/g and 5-20 mass parts of gypsum for a total of 100 mass % and 0.5-1.5 mass parts or 5-45 mass parts of an alkaline stimulant. Such concrete compositions can maintain superior operability by reducing the discharged amount of carbon dioxide and the decrease with time in fluidity and air content of the prepared concrete compositions. They can also reduce the drying shrinkage of the obtained hardened objects and allow the obtained hardened objects to manifest necessary strength.

Purified air is provided, having a TVOC content of from less than 5 ppb to about 500 ppb, a Biologicals content of from less than 1 CFU/M³ to 150 CFU/M³ and a Particulate content of from about 1,000 0.3 μm particles per ft³ to about 50,000 0.3 μm particles per ft³, or from about 600 0.5 μm particles per ft³ to about 500,000 0.5 μm particles per ft³.

The invention discloses an early-strength polycarboxylate superplasticizer having a slump-loss prevention function and a preparation method of the polycarboxylate superplasticizer. The polycarboxylate superplasticizer is prepared through the following steps: (I) copolymerizing 5-12% of a monomer a, 73-89% of a modified low-foam early-strength polyether monomer b with the molecular weight (M) in a range of 2000-5000, and 6-15% of a monomer c in an aqueous solution at 50-70 DEG C to obtain a copolymerization reactant, wherein the total amount of the monomer a, the monomer b, and the monomer c is 100% by weight; and (II) adding a pH value conditioning agent into the copolymer for a neutralization reaction, wherein the pH value of the copolymer is adjusted to 6.8-7.2. According to the invention, the early-strength polycarboxylate superplasticizer having a slump-loss prevention function enables the fluidity of cement paste of concrete to be well kept. The concrete is low in air content and short in setting time, and the early-strength of the concrete is significantly enhanced. The polycarboxylate superplasticizer enables the concrete to have certain slump maintenance, and is particularly suitable for production of a prefabricated component of a pile tube or duct piece.

The invention provides emulsified asphalt for a slab ballastless track, which comprises the following materials in percentage by weight: 55-65% of asphalt, 3-10% of cationic emulsifier, 3-10% of nonionic emulsifier, 1-5% of stabilizer and the balance water. The emulsified asphalt can effectively avoid the separation of cement-asphalt (CA) mortar and enable the working time of CA mortar to be up to one hour. The CA mortar prepared from the emulsified asphalt has high early strength, and the air content, the fluidity, the early strength, the material separation degree and other indices of the CA mortar are easy to control. The emulsified asphalt has favorable storage stability, and can be stored for at least six months at 0-40 temperature without stratification and separation, thereby facilitating transportation and storage. Besides, the emulsified asphalt can not corrode steel devices and steel bars in concrete.

A high-speed turbine mixer combines water and cement into a pre-mixed cement paste that is added to aggregates to create a concrete mix. The turbine mixer includes a housing that cooperates with an auger to move dry cement into a mixing chamber where water is added. A mixing plate rotates at high speed to break up water and cement into small particles that enhances the hydration of the cement and increases the air content in the resultant cement paste. The cement paste is then conveyed to a mixing auger to be combined with aggregates to create a concrete mix. The mixing plate divides the mixing chamber to force the mixing water and cement particles to pass through a circumferential annular opening past agitating fins. Admixtures can be added to the cement as a powder or to the water as a liquid for incorporation into the cement paste.

The invention relates to an efficient and reliable simulation machine eagle device which can faithfully protect farmland grains and plants, is driven by solar energy for realizing unmanned and automated farmland protection. The solar-energy machine eagle utilizes solar-energy batteries to generate electrical power, and utilizes a controller to control and drive a direct-current motor to drive a minitype turbofan to rotate at a high speed and generate air flows jetting backwards to impel the model body of the simulation eagle. Meanwhile, the eagle model generates action effects of soaring high up in the air and hovering by buoyancy generated by a hydrogen wing bag and atmosphere lift force caused by elevation angles of two wings and by controlling the pivot angle of a tail rudder and the air content of the left and the right hydrogen wing bags and the front and rear hydrogen wing bags by the controller under the control of a remote controller, frightening and deterring animals such as cocks, birds, mice, and the like from stealing farm crops in farmland, particularly in large area of grainfield which cannot be protected by manpower.

The invention discloses an air-entraining type polycarboxylate superplasticizer and a preparation method thereof, and belongs to the technical field of concrete admixtures, wherein the air-entrainingtype polycarboxylate superplasticizer comprises the following raw materials: 20-40 parts of a polyether macromonomer, 5-20 parts of a vinyl micromonomer, 1-10 parts of tea saponin, 0.1-0.5 part of a catalyst, 1-6 parts of an initiator and the balance being water. The excellent foaming and foam stabilizing capabilities of the natural nontoxic product tea saponin are utilized, so that the compatibility problem of the polycarboxylate superplasticizer compound air-entraining agent and the problem of poor stability of the air content in concrete are fundamentally solved. The air-entraining type polycarboxylate superplasticizer product provided by the invention is good in air-entraining performance, high in water reducing rate and high in concrete air content retention rate, and the long-term and durable performance of concrete can be remarkably improved.

The invention relates to a method for preparing an air entrainment-controllable polycarboxylate water-reducing agent. The method comprises the following steps: an aqueous solution of polyethylene glycol methyl ether methacrylate and methylacrylic acid is added dropwise into 75-80 DEG C water and an aqueous initiator solution is added dropwise in water at the same time, the temperature is maintained at 75-80 DEG C and the addition of reactants is completed within 6-7 hours, the temperature is maintained at 78-80 DEG C for 2-3 hours, the reaction product is naturally cooled down to room temperature and neutralized with a diluted alkali solution until the pH value is in the range from 6.5 to 7.5, and the air entrainment-controllable polycarboxylate water-reducing agent is obtained. The method has the advantages of simple synthetic processing equipment, controllable reaction conditions, no pollution, low cost and suitability for industrialized production. Under the condition of low mixing amount, the synthesized air entrainment-controllable polycarboxylate water-reducing agent exhibits high water-reducing rate, good fluidity and fluidity retention, and controllability in air content; and can efficiently increase concrete workability, prevent the bleeding and segregation of concrete and improve the frost resistance and water impermeability of hydraulic concrete.