23 results about "Air content" patented technology

The invention relates to the technical field of concrete durability evaluation, in particular to a compound green concrete salt freezing resistance durability evaluation system under a frozen soil environment, which comprises a data input unit, a decision information table storage unit, a rough set analysis processing unit and an evaluation output unit, the data input unit receives a sample data set containing freeze-thaw cycle times, dry-wet cycle times, freeze-thaw-dry-wet cycle times, long-term soaking time, composite salt concentration, gas content and fly ash mixing amount, and the decision information table storage unit stores a decision information table constructed based on a rough set theory. The influence factor combination and the relative dynamic elastic modulus percentage are associated, the rough set analysis processing unit establishes a mapping relation through attribute reduction and rule extraction and quantifies the weight of each factor, and the evaluation output unit outputs a relative dynamic elastic modulus predicted value, durability grade classification and key factor contribution sorting. And the salt freezing resistance durability of the concrete under the multi-factor coupling effect is accurately evaluated.

This application discloses a micro-expansion low-heat silicate cement-based concrete material, its preparation method, and its application, belonging to the field of concrete engineering technology. Each cubic meter of micro-expansion low-heat silicate cement-based concrete material comprises 78-92 kg of water, 82-161 kg of micro-expansion low-heat silicate cement, 28-105 kg of fly ash, 476-608 kg of sand, and 1286-1696 kg of aggregate. The dosage of naphthalene-based water-reducing agent is 0.4 wt%-0.6 wt%, and the dosage of air-entraining agent is 0.014 wt%-0.018 wt%. The air content of the concrete material in the mixed state is 4%-5%, and the slump is 35-50 mm. Through the synergistic proportioning of water, micro-expansion low-heat silicate cement, fly ash, sand, and aggregate, the low heat of hydration and micro-expansion characteristics of micro-expansion low-heat silicate cement are fully utilized.

This invention discloses a method for predicting the air content of hardened cement mortar, comprising: obtaining the mix proportion of cement mortar, wherein the raw materials of the cement mortar include cement-based cementitious materials, water, sand, and admixtures, and the mix proportion is 1:w:x:y, where w is the amount of water, x is the amount of sand, and y is the amount of admixtures; obtaining the density of the raw materials of the cement mortar; obtaining the trend of the cumulative water absorption of sand over time; testing the apparent density of the cement mortar mixture; testing the setting time of the cement mortar; calculating the first water absorption rate and the second water absorption rate of sand; calculating the hysteretic water absorption of sand; and calculating the air content of the hardened cement mortar. This invention solves the problem of inaccurate or untimely detection of the air content of cement mortar by introducing the hysteretic water absorption of sand.

The utility model belongs to the technical field of concrete detection, and particularly relates to a concrete gas content tester, which comprises a tank body, a cover and a fixing device, the cover is positioned on the upper surface of the tank body, and the upper surface of the cover is fixedly connected with a barometer; the fixing device is arranged on the surfaces of the tank body and the cover and comprises two placement plates, the two placement plates are located on the two sides of the tank body, the surfaces of the tank body and the cover are sleeved with two lantern rings, moving blocks are fixedly connected to the positions, close to the placement plates, of the bottom ends of the lantern rings, guide rods are fixedly connected to the inner surfaces of the placement plates, and a placement device is arranged on the surface of the tank body; the placing device comprises a fixing ring and a gasket, the fixing ring sleeves the surface of the tank body, the side wall of the fixing ring is fixedly connected with a base plate, and the gasket is located on the upper surface of the base plate; by arranging the whole device, the cover and the tank body can be conveniently fixed together, the situation that operation is tedious during traditional fixing operation is reduced, and therefore the mounting and dismounting efficiency is improved.

This utility model discloses an air content measuring instrument for concrete mix design, including a loading assembly. The loading assembly includes a measuring bowl, inside which a mixing assembly is installed. A measuring assembly and a sealing assembly are installed on the top of the measuring bowl. The measuring assembly includes a bowl cover that is fixedly and movably installed on the top of the measuring bowl. Through the setting of the sealing assembly, this utility model utilizes the connection relationship between the support frame, fixing ring, screw, moving block, four sets of rotating seats, four sets of connecting rods, four sets of clamping blocks, and four sets of clamping grooves. Rotating the screw clockwise or counterclockwise indirectly drives the four sets of clamping blocks to move closer or further apart. When they move closer, the V-shaped clamping grooves on the inner side of the four sets of clamping blocks clamp and fix the measuring bowl and bowl cover. When they move further apart, the V-shaped clamping grooves on the inner side of the four sets of clamping blocks release the clamping and fixing of the measuring bowl and bowl cover. This achieves the effect of controlling the opening and closing of the bowl cover by rotating the screw alone, thereby improving the efficiency of the air content measuring instrument.

To provide a cement composition giving a cured product excellent in stability of air content, property of preventing intrusion of substances, drying shrinkage and resistance to freezing and thawing in addition to high strength.SOLUTION: A cement composition comprising microcapsules with a core-shell structure having a core consisting of a water repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensates and branched siloxane resins, and a shell of a silicon-based network polymer comprising silica units, and cement, wherein the microcapsules are present in an amount of 0.01 to less than 0.5 parts by weight per 100 parts by weight of cement.SELECTED DRAWING: None

The invention discloses an air entraining agent for roller compacted concrete and a preparation method of the air entraining agent. The air entraining agent is prepared by compounding an air entraining component A, an air stabilizing and enhancing component B and a sensitivity reducing component C according to the weight part ratio of (450-550): (250-350): (100-300). The air entraining component A is prepared through esterification and quaternization of modified rosin, the air stabilizing and enhancing component B is prepared by dispersing nano silicon dioxide and the like, and the sensitivity reducing component C is a multi-surfactant compound system. Through the synergistic effect of the three components, the problems that a conventional air entraining agent is poor in air entraining effect in roller compacted concrete, bubbles are prone to being damaged, and the air content is sensitive to the VC value are solved, the freezing resistance and impermeability of the concrete can be remarkably improved, the early and later compressive strength is guaranteed, and the air entraining agent is suitable for construction of water conservancy dam bodies in high-altitude severe cold areas and has good practicability and popularization value.

The application discloses a kind of concrete based on mix proportion optimization and performance prediction and preparation method thereof, belong to building material technical field.The concrete preparation method of the application, with water-cement ratio, mineral admixture content, admixture composition as orthogonal test factor, the air void ratio of each test group cement stone, slurry volume fraction and in the case of considering air content are calculated, and the 28d compressive strength of each test group is calculated and predicted;Through contour map, the influence of mix proportion parameters on the 28d compressive strength and microstructure of concrete is obtained, and the water-cement ratio and cementitious material composition are selected from the contour map according to the performance design requirements of concrete.The application can design multiple strength grade concrete simultaneously, and is suitable for wharf, approach bridge, pile cap, wave protection wall and offshore wind power foundation and other marine structures in marine chlorine salt environment, to provide scientific basis and reliable technical support for preparing low-carbon, high-performance, ultra-high performance, mix proportion optimization and performance prediction based concrete, especially marine concrete.

The invention provides an anti-freezing agent for concrete in an ultralow-temperature high-altitude environment, anti-freezing concrete and a preparation method of the anti-freezing concrete, and belongs to the technical field of concrete. The anti-freezing agent for the concrete in the ultralow-temperature high-altitude environment comprises a first component and a second component, the first component comprises nano crystal nucleus powder and inorganic salt anti-freezing powder, and the second component comprises a nano composite air entraining agent and a foam stabilizer; the mass ratio of the nano crystal nucleus powder to the inorganic salt anti-freezing powder to the nano composite air entraining agent to the foam stabilizer is (20-60): (20-60): (20-60): (0.1-10). The ultralow-temperature anti-freezing early-strength concrete is prepared from the nano-crystal nucleus super-early-strength component, the inorganic salt anti-freezing component, the nano air entraining component and the foam stabilizing component, the construction performance and anti-freezing and early-strength requirements of the concrete in an ultralow-temperature high-altitude environment are met, the applicable temperature can reach-30 DEG C, meanwhile, the long-term durability of the concrete in a freezing and thawing cycle environment is improved, and the concrete has good anti-freezing and early-strength properties. The problems of fast air content loss, large slump loss, poor bubble stability and the like caused by high altitude and low air pressure are solved.

The present application provides a kind of concrete, which is made of the following raw materials by weight: cement 410-420 parts, sand 830-840 parts, stone 930-940 parts, water 135-140 parts, water reducing agent 7.2-7.6 parts, defoaming agent 0.4-0.8 parts, composite active powder admixture 80-90 parts, silica fume 30 parts, wherein the composite active powder admixture is a mixture of mineral powder and fly ash with a mass ratio of 1:1. The present application also provides an application, which is used for preparing prefabricated tower segment or concrete pole. The concrete of the present application can greatly reduce the amount of cement, reduce the overall cost, has low air content, the bubble layer on the inner wall of the pole is completely eliminated, the durability is significantly improved, the service life is prolonged, can adapt to the inclined whole mold feeding system in the production of power poles, and can be used for producing lightweight, high-strength prefabricated tower segments.

The application relates to a heat-resistant concrete suitable for high-temperature tunnel secondary lining, which comprises the following components and contents (mass parts): low-heat portland cement 250-320, mineral admixture 60-120, coarse aggregate 950-1150, machine-made sand 650-850, micro aggregate 5-35, hydration heat inhibitor 0-2.0, high-temperature adaptive water reducing agent 3.6-4.4, defoaming agent 0-0.04, and water 145-160, wherein the mixing material has a mold content air content of less than or equal to 4%. Compared with the prior art, the product has the technical advantages of small working property loss, low later strength damage and good crack resistance in a high-temperature environment.

The invention provides a viscosity reduction type polycarboxylic acid water reducing agent and a preparation method thereof, and belongs to the technical field of water reducing agents. The viscosity reduction type polycarboxylate superplasticizer provided by the invention can remarkably improve the construction and working performance of high-performance concrete, effectively reduce the viscosity of a concrete mixture, and improve the fluidity and homogeneity of the concrete mixture, so that smooth pumping construction is guaranteed; meanwhile, the water reducing agent can stably control the gas content of the concrete on the premise of improving the workability, ensures that the concrete has good compactness and microstructure after being hardened, and finally achieves the comprehensive effect of improving the mechanical strength and long-term durability of the concrete; in addition, the preparation process conditions are mild, a high-temperature and high-pressure environment is not needed, the production process is simplified, energy consumption and production cost can be reduced, and good economical efficiency and large-scale application prospects are achieved.

The invention relates to the technical field of plateau concrete mix proportion, aims to solve the problems that conventional concrete in the prior art cannot adapt to plateau low-temperature, large-temperature-difference and low-air-pressure environments, the strength of the concrete rises slowly, cracks are prone to being generated, and durability is insufficient, and provides an anti-crack concrete mix proportion suitable for a plateau area and a construction method of the anti-crack concrete mix proportion. The cement consumption is low, and part of cement is replaced by fly ash; the high-performance water reducing agent is low in water-binder ratio, and the water-binder ratio is 0.3; the hydration heat is low, and the cement hydration reaction rate is slowed down by adjusting the use amount of the fly ash and the high-performance water reducing agent; the air content is high, tiny bubbles in the concrete are controlled, and the air content is controlled to be 3.2%-4.0%. The method has the beneficial effects that the gradation of gelling and aggregate is optimized, the 28d compressive strength is greater than or equal to 63.5 kg / m, and the freezing resistance is greater than or equal to F300; temperature difference tensile stress is reduced, and cracks are inhibited; the constructability of the mixture is guaranteed, the cracking risk of the concrete is reduced, the strength is high, the durability is strong and the service life is long.

The invention discloses concrete based on mix proportion optimization and performance prediction and a preparation method thereof, and belongs to the technical field of building materials. According to the concrete preparation method disclosed by the invention, the water-binder ratio, the mineral admixture dosage and the admixture composition are taken as orthogonal test factors, the binder-air ratio and the slurry volume ratio of cement stone of each test group are calculated, and the 28d compressive strength of each test group is calculated and predicted under the condition that the gas content is considered; the influence rule of the mix proportion parameters on the 28d compressive strength and microstructure of the concrete is obtained through the contour map, and the water-binder ratio and the cementing material composition are preferably selected from the contour map according to the concrete performance design requirements. And according to the workability design requirements of the concrete, the slurry volume ratio, the water consumption and the optimal sand ratio are calculated. According to the method, concrete with multiple strength grades can be designed at the same time, and a scientific basis and a reliable technical support are provided for preparing concrete which is low in carbon, high in performance and ultrahigh in performance and is based on mix proportion optimization and performance prediction.

The invention relates to the technical field of building construction, in particular to a concrete pouring method which solves the problems that in the existing concrete pouring process, gas content control depends on manpower, response lags behind, and precision is insufficient. According to the technical scheme, a non-contact ultrasonic gas content monitoring sensor and a pressure sensor are installed at the outlet end of a conveying hose of a concrete pump and a hydraulic system respectively and connected with a controller, and the controller is connected with an air entraining agent metering pump and a defoaming agent metering pump at the same time; the air content and pumping pressure data are monitored in real time, the controller compares the preset range of the air content and calculates the pumping pressure change rate, the adding operation of an air entraining agent or a defoaming agent is automatically triggered, meanwhile, the pumping speed is adjusted, and finally continuous and automatic regulation and control over the air content of concrete are achieved. The method is mainly used in mass concrete pouring construction, the gas content of concrete can be stably controlled, and the construction quality is improved.

To provide a fiber-reinforced mortar composition which reduces the amount of cement to be used, is excellent in workability, and is also excellent in curing characteristics such as compressive strength, bending strength and split tensile strength.SOLUTION: A fiber-reinforced mortar composition comprising: a cement composition comprising cement, a pozzolanic substance comprising blast furnace slag, and fine aggregate; and polypropylene-based short fibers, wherein a mass ratio of the cement is 10 to 35 mass% with respect to a mass of the cement composition, A mass ratio of the pozzolanic material is 30 to 60% by mass with respect to a mass of the cement composition, a volume ratio of the polypropylene short fibers is 2.5 to 5% by volume with respect to a total volume of the cement composition, and an air content at the time of completion of mixing is 7 to 15%, the air content being measured at 20 °C according to "6.5 Air content test" described in JISA1171:2016 "Testing methods for polymer cement mortars".SELECTED DRAWING: None

This invention relates to the field of building materials technology, and more particularly to a dispersant for high-volume solid carbon steel slag powder cementitious materials and its preparation method. The dispersant is a multi-block comb polymer, and the main chain of the multi-block comb polymer, from one end to the other along the chain direction, sequentially includes a first rheology-regulating block R1, a steel slag affinity block S, a cement dispersion block C, and a second rheology-regulating block R2. This invention can be used to adjust the cohesiveness, bleeding tendency, and air content of high-volume solid carbon steel slag powder concrete, achieving directional recognition and selective adsorption on the surface of solid carbon steel slag powder. It also provides efficient dispersion and slump retention for cement clinker and hydration product particles. Simultaneously, this invention can reduce the viscosity of concrete, while avoiding bleeding and segregation. The air bubbles are small and dense, improving the fluidity and pumpability of the mixture, while ensuring good early strength and long-term durability.

According to this method, the solids are packed together with an air portion into individual bags (63) of an endlessly fed hose and the buoyant bag (63) is hermetically sealed and released into the sewer system. The device for this purpose includes at least the following technical components after the siphon of the WC (100) for treating the siphon outlet within a closed system:a solids separation tank (3) for collecting the solids,a solids pump (28) for conveying the separated solids upwards in a riser pipe (4) into a high-level solids tank (5),a portioning device (6) with a dosing valve (7) for dropping portions of solid material into a tubular bag packaging unit (9) arranged underneath,a tubular bag packaging unit (9) for producing hermetically sealed and subsequently separated bags (63) with solids and an air content from an endlessly fed tube, for discharge into the sewage system.

The invention discloses a high-foam-stability concrete air entraining agent with a multi-substructure and a preparation method of the high-foam-stability concrete air entraining agent. The air entraining agent comprises a polyamine main chain, a hydrophobic chain mounted on the polyamine main chain and a phosphonate anion functional group grafted on the polyamine main chain. The molecular structure of the air entraining agent provided by the invention has the advantages of multi-type, high surface activity, lower solid doping amount compared with the conventional air entraining agent, uniform and fine bubbles can be generated when the air entraining agent is added into premixed concrete, the stability of the bubbles in time is excellent, the workability of the premixed concrete can be greatly improved, and the bleeding rate and the slurry bleeding rate are obviously reduced; the branched chains are multi-sub-chains, good air entraining and foam stabilizing effects are achieved, the main chain has a good reinforcing effect, concrete strength reduction caused by increase of the air content is made up, and the air entraining and foam stabilizing performance of the whole system is kept excellent; phosphonic acid groups in molecules of the air entraining agent are insensitive to components of concrete and mineral admixtures and have relatively weak adsorption capacity to clay, so that the air entraining agent has relatively good retarding and slump retaining properties.

A precast concrete molded body is provided, which is a cured product of a concrete composition. The concrete composition comprises: a microcapsule; cement; and at least one type of aggregate. The microcapsule is provided with a core-shell structure having i) a core made of a water repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell made of a silicon-based network polymer containing silica units. The concrete composition contains 0.01 to less than 0.5 parts by weight of microcapsules per 100 parts by weight of cement. Thereby, a precast concrete molded body can be provided, having high strength, as well as at least one of the following properties: air content stability, substance penetration prevention, and freeze-thaw resistance.

This utility model relates to the field of concrete air content testing technology, and discloses a concrete air content testing device, including a supporting base shell. A tamping mechanism is arranged on the top left side of the supporting base shell, and a fixing mechanism is arranged on the top right side of the supporting base shell. The fixing mechanism is used to fix the testing device. The tamping mechanism includes a mounting shell and a transmission belt. The bottom of the mounting shell is fixedly connected to the top left side of the supporting base shell. Transmission wheels are rotatably connected to the left side of the inner walls of both the supporting base shell and the mounting shell. The two transmission wheels are connected by a transmission belt. A motor is fixedly connected to the left side of the supporting base shell. In this utility model, the transmission belt causes the transmission wheels on both sides to rotate synchronously. Through the rotation of the measuring bowl and the reciprocating motion of the tamping rod, the concrete inside the measuring bowl is tamped in all directions, ensuring the depth, force, and uniformity of the tamping.

The application belongs to the technical field of processing equipment of suspension roller pendulum type flour mill, and particularly relates to an air inlet volute with air content distribution structure suitable for a European pendulum type flour mill, which comprises a volute shell, a plurality of air deflectors and a plurality of ventilation channels are arranged in the shell, the plurality of air deflectors are arranged in a uniform equidistant manner along a clockwise circular axial surface, the included angle between the planes of the surfaces of two adjacent air deflectors is an acute angle, the plurality of ventilation channels are arranged in a counterclockwise ring around the circular axial surface of the plurality of air deflectors, the ventilation channel comprises a plurality of arc-shaped air baffles, the plurality of arc-shaped air baffles are arranged in a sequence from inside to outside along the circular axial surface of the volute shell and arranged in a sequence from short to long in length, and the ventilation channel comprises an air inlet section which is connected with an air inlet. The application has uniform air outlet direction and high flow rate.

The present invention relates to a concrete composition used in the manufacture of a concrete structure, a method for manufacturing a concrete composition, and a concrete structure. In particular, by calculating the water content of a saturated nanocellulose water dispersion as part of the mixing water and correcting the amount of externally added water in an actual precast concrete secondary product production process, the invention suppresses variations in effective water content, deviations in the water-to-binder ratio, reduction in slump, increase in viscosity, variations in air content, and non-homogenization of mixing, and ensures mix reproducibility, quality homogeneity, production stability, steam curing stability, and early demolding stability. The invention also relates to a concrete composition, a method for manufacturing the same, and a concrete structure manufactured thereby.