43 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.

The invention discloses a high-performance concrete detection method, and relates to the technical field of concrete detection. Comprising the following steps: sampling: performing segmented sampling and uniform mixing in an unloading process, acquiring image information of a sample, analyzing and pre-judging risks, generating a unique electronic tag for the sample, and binding related information of the batch of high-performance concrete; and fresh mixing performance testing: monitoring discharge rheological parameters in real time, automatically testing integrated slump, expansion degree, volume weight and gas content of the sample, judging workability and deciding pouring. According to the method, the solid curing test piece is manufactured and cured in the environment which is completely the same as the solid structure, the measured strength can more accurately reflect the actual development condition of solid concrete, the strength of the solid concrete is compared with the strength of the standard curing test piece, and the field curing effect is scientifically evaluated; the problem of high-performance concrete or the problem of field maintenance conditions can be better judged, and the accuracy of a detection result is improved.

A rapid testing device for the water-binder ratio of a concrete mixture relates to the technical field of concrete quality detection and comprises a workbench, a support, a sampling container, a concrete gas content tester and a control mechanism, the top end of the workbench is connected with the support, the sampling container is installed on the support and provided with a weighing mechanism, and the weighing mechanism is connected with the control mechanism. A concrete gas content tester is arranged at the top of the working table below the sampling container, the weighing mechanism is in signal connection with the control mechanism through a wire, and the control mechanism is provided with a calculation module, a storage module, an input module and a display screen. The device can quickly measure the water-binder ratio of the concrete mixture, is convenient to clean, does not need to evaporate the moisture of the mixture, and further improves the test efficiency and the accuracy of the test result.

The invention discloses a preparation method of anti-freezing concrete suitable for a high-altitude environment. The preparation method comprises the following steps: firstly, carrying out pre-water absorption treatment on coarse aggregate to obtain pre-treated coarse aggregate, wherein the pre-water absorption rate is 1.5 times of the saturated surface dry water absorption rate; mixing the anti-freezing fiber and the bubble stabilizer; and finally adding the cementing material, the water, the fine aggregate and the additive, and mixing to obtain the concrete. The bubble stabilizer is superfine particles, and the anti-freezing fibers comprise low-elastic-modulus fibers and high-elastic-modulus fibers. By adding the fiber combination, the air entraining agent can be assisted in introducing more beneficial bubbles in the stirring process, a dense network is formed in a concrete mixture and a cement matrix, the bubbles introduced under low air pressure are prevented from overflowing, and meanwhile, the air hole structure of the concrete is optimized through the bubble stabilizer to maintain the air content of the concrete. The fiber composition has a synergistic effect in the hardened concrete, and under the combined action of the fiber composition and the hardened concrete, the anti-freezing durability of the concrete in the high-altitude low-air-pressure environment is remarkably improved.

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.

The utility model relates to the technical field of mortar mixing interface agent preparation, in particular to a temporary storage device convenient to seal and unseal, which comprises a barrel body, a barrel cover, a bump, a piston plate and a driving mechanism. An annular gasket is arranged on the inner wall of the barrel body. A lock catch assembly is arranged on the can cover. The protruding block is connected with the upper wall of the concave face of the barrel cover, the outer wall of the protruding block is provided with a landing edge, and a sealing gasket is arranged at the bottom of the landing edge. A one-way air inlet pipe which is communicated with the inner bin of the barrel body and the cylindrical groove in a one-way mode is arranged at the bottom of the protruding block. The piston plate is in sliding connection with the inner wall of the cylindrical groove, and a one-way exhaust pipe for unidirectionally communicating the cylindrical groove with the outside is arranged on the piston plate. The driving mechanism comprises a reciprocating driving assembly and a ventilation assembly. The reciprocating driving assembly drives the piston plate to slide in a reciprocating mode. And the ventilation assembly is communicated with the outside and the inner bin of the barrel body in a working state. The barrel cover is convenient to open and close, and the drying and hardening speed of wet-mixed mortar is slowed down by reducing the air content in the barrel body.

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 invention relates to the technical field of building material detection, in particular to a building mortar gas content tester. According to the technical scheme, the device comprises a measuring bowl, an extension edge, an upper cover, a buckle clamp, a knocking leveling assembly, a reciprocating pushing assembly and the like, wherein the extension edge is arranged at the upper part of the measuring bowl; the upper cover is connected with a plurality of clasps; the upper cover is connected with the measuring bowl through a plurality of clasps. Through the arrangement of a rotary telescopic rod of the knocking leveling assembly, the horizontal stability of the device can be realized, and a worker does not need to continuously find an area meeting the working requirement for detection; through cooperation of the reciprocating pushing assembly and the knocking and leveling assembly, the problems that in the prior art, a construction site is often lack of professional equipment such as a vibration table, a detection container is knocked through simple tools such as a rawhide hammer and a wooden stick, and thoroughness of bubble removal is difficult to guarantee are solved.

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.

The invention discloses a concrete freezing resistance evaluation method suitable for a high-altitude low-pressure environment. The method comprises the following steps: stirring and forming a concrete test piece in a low-pressure environment; soaking a group of test pieces for 4 days until the test pieces are saturated with water, putting the test pieces into a freezing stress test barrel, setting freezing and thawing cycle test air pressure and frozen concrete test piece center temperature according to the actual operation environment of the high-altitude cold region project, and drawing a freezing stress development curve in the freezing and thawing cycle process; finally, a freezing stress inflection point value is obtained through the freezing stress development curve in the freezing and thawing cycle process, the lower the freezing stress inflection point value is, the more excellent the anti-freezing performance is, and it is judged that concrete is subjected to freezing and thawing damage according to inflection points changing from large to small in the freezing stress development curve. According to the method, the anti-freezing performance of the concrete in the low-pressure environment is evaluated through the freezing stress, the defect of controlling the gas content of a concrete mixture in the high-altitude low-pressure environment is effectively avoided, and the anti-freezing durability in the actual engineering concrete service process can be evaluated more accurately.

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 present invention provides a test device for the air content of concrete under constant temperature and humidity, which relates to the field of testing the air content of concrete. The test device for the air content of concrete under constant temperature and humidity includes a bowl body and a bowl cover. A constant temperature chamber, a cavity and a pressurization chamber are arranged inside the bowl body. A rotating cylinder for storing concrete is rotatably installed on the inner side of the bowl body. An air inlet and an air outlet are formed in the cavity, and an opening is arranged inside the rotating cylinder. For the test device for the air content of concrete under constant temperature and humidity, chambers of different levels can independently and precisely control and adjust different pressure ranges. The chamber with the highest pressure can preliminarily measure and balance larger bubbles, and the chambers with lower pressures respectively measure medium-sized and tiny bubbles. This hierarchical measurement method can capture the pressure changes generated by bubbles of different sizes more accurately. Compared with a single air pump for switching pressures, it can measure the air content in concrete more accurately.

The utility model belongs to the technical field of building mortar gas content detection, and particularly relates to a building mortar gas content high-precision measuring device which comprises a base, two symmetrical sliding grooves are formed in the top of the base, an elastic moving assembly is arranged in each sliding groove, and an arc-shaped support is arranged at the top of each elastic moving assembly. A connecting plate and a first arc-shaped magnetic block are sequentially arranged on one side of the arc-shaped support from top to bottom, a bearing cylinder used for bearing mortar is installed at the end, away from the arc-shaped support, of the connecting plate, a sealing cover is arranged on the top of the bearing cylinder, a pressure gauge is arranged on the sealing cover, and a double-shaft motor is installed at the bottom of the bearing cylinder. A stirring assembly located in the bearing cylinder is installed at one output end of the double-shaft motor, and a rotating disc is installed at the other output end of the double-shaft motor. According to the device, through the synergistic effect of stirring and vibration, bubbles in mortar are more uniformly distributed, so that the gas content can be more accurately measured, and the measurement error is reduced.

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 utility model relates to the field of building material concrete determination, in particular to civil building material concrete gas content determination equipment, which comprises a placement tank, a gas detection device and a gas detection device, according to the utility model, the rotary drum drives the gear ring to rotate and simultaneously drives the plurality of groups of gears to rotate, so that the gears drive the nut to move along the screw rod, and the nut pushes the tank cover to approach the placing tank while rotating in the fixed drum, so that the sealing performance of the placing tank is ensured. The butt joint ring moves towards the interior of the containing tank, meanwhile, the tank cover and the containing tank extrude the rubber ring, the tighter the rubber ring is drawn close, the better the sealing performance is, and due to the fact that in the mode, the rotary drum drives the gear ring and drives the multiple sets of gears to rotate at the same time, the rotating positions of all the sets of nuts on the threaded rod are the same, the attaching tightness of the tank cover and the containing tank is guaranteed, and the service life of the tank cover and the containing tank is prolonged. And in this way, the tank cover can be quickly mounted and dismounted, and the convenience of the tank cover is improved.

The embodiment of the application discloses a kind of intelligent concrete construction equipment and its construction method, it is related to building construction field, intelligent concrete construction equipment includes conveying system, bunker, bunker has feed cavity and its one end is provided with discharge pipe, bunker lower end or discharge pipe lower side is provided with discharge port, discharge port is provided with on-off piece, intelligent concrete construction equipment further include quality detection device, test block mould conveying device, vibration device and marking device, quality detection device is used to detect the workability and air content of concrete;Test block mould conveying device is used to convey test block box to material receiving station and marking station.The embodiment of the application realizes the use of quality detection device, test block mould conveying device, vibration device, marking device, can ensure that the workability and air content of concrete meet preset strength requirement, and whole course automatic manufacturing test block, reduce manual labor, effectively improve the efficiency of building construction.

The utility model relates to the technical field of construction detection equipment, and discloses a concrete air content measuring device which comprises a bowl body, a water injection device, an air inflation device and a numerical control device. An air port of the air inflation device is connected with the bowl body and communicated to the interior of the bowl body, and the numerical control device is arranged on the bowl body and electrically connected with the water injection device and the air inflation device; according to the utility model, the water injection device and the air inflation device are arranged to automatically inject water into the measuring device and automatically inflate the measuring device during a test, so that human resources are optimized; meanwhile, the bowl bodies are connected through the electromagnetic adsorption device, and the bowl bodies and the electromagnetic adsorption device can be tightly adsorbed together after being electrified so as to prevent the gas content tester from leaking water or gas in the test process. And after the test is finished, the electromagnet loses magnetism to separate the two.

The utility model relates to a tubular sliding contact line which comprises an insulating shell, openings are formed in the two ends of the insulating shell, a lower notch is formed in the lower end of the insulating shell, box bodies are arranged at the two ends, close to the openings, of the insulating shell, first shielding assemblies used for shielding the openings are arranged in the box bodies, and a groove is formed in the side wall of the lower notch. When the external temperature is low, the first shielding assembly shields the opening, the second shielding assembly shields the lower notch, at the moment, most of channels through which cold air enters the insulating shell are blocked, the content of the cold air entering the insulating shell is reduced, and therefore water drops generated in the insulating shell are reduced, and the heat dissipation performance of the insulating shell is improved. And the humidity of air in the insulating shell is effectively reduced. The method has the effect of reducing the possibility of safety accidents.

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 invention discloses a preparation method of low-hydration-heat concrete for preventing early cracks of a wall. According to the method, various measures are comprehensively adopted, and the method specifically comprises the steps that the hydration heat of a cementing material at the one-day age is limited to be not higher than 50 J / g, the hydration heat of the cementing material at the three-day age is limited to be not higher than 200 J / g, and the hydration heat of the cementing material at the seven-day age is limited to be not higher than 250 J / g; a high-quality air entraining agent is doped, and the air content is controlled within the range of 3%-5%; the retarder is doped, and the final setting time of the concrete under the same condition is controlled within the range of 12-20 hours, so that the hydration heat release rate is reduced, and the anti-cracking performance of the concrete is improved. Quantitative systematic control on key node values such as hydration heat of a cementing material, gas content of concrete and setting time of the concrete is innovatively proposed, so that early cracks of the concrete are effectively inhibited, and economical efficiency and construction convenience are taken into account at the same time. The method is suitable for a concrete wall structure with the strength grade of C30 to C40, aims to solve the problem of early cracks, and can provide reference for related preparation of concrete with higher strength grade.

To provide a technique that enables non-contact prediction of cement mixture air content regardless of skills of measurers.SOLUTION: A cement mixture air content prediction method is provided, comprising irradiating an uncured cement mixture with light to measure reflectance of the light irradiated on the cement mixture using a reflectometer, and predicting air content of the cement mixture on the basis of the measured reflectance.SELECTED DRAWING: Figure 2

The invention is suitable for the technical field of packaging machines, and provides a ton bag packaging machine telescopic pipe blanking air extractor which comprises a telescopic pipe assembly fixed to a rack through a sliding table fixing frame, a blanking pipe is fixed to the lower portion of the center of an upper platform of the rack, a telescopic pipe of the telescopic pipe assembly movably sleeves the blanking pipe, a bag clamping pipe of a bag clamping hopper is connected with the rack, and the bag clamping hopper is connected with the sliding table fixing frame. The bag clamping hopper penetrates through the lower end of the telescopic pipe, a dust removal cover is arranged at the upper end of the bag clamping hopper, the dust removal cover and the telescopic pipe are connected through a rubber telescopic sleeve, the telescopic pipe and the discharging pipe are connected through a rubber telescopic sleeve, and two dust removal cover limiting rods are symmetrically arranged between the discharging pipe and the dust removal cover. In the ton bag packaging process, air in the bags is exhausted, air in materials in the packaging bags is rapidly exhausted, material bottom discharging of the ton bags is achieved, mixing of the materials and the air is reduced, the air content in the materials is reduced, and therefore the packaging speed is increased; and in cooperation with a dust removal cover, the overflow dust amount is reduced in the discharging and packaging process, the working environment is improved, and environmental protection and human health are facilitated.

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 utility model relates to the technical field of pipeline construction, in particular to a gas content tester for a concrete pipeline foundation. Comprising a barrel body provided with a barrel edge; the cover body is provided with a cover edge; the buckling mechanism is used for fixing the cover body on the barrel body; the buckling mechanism comprises a connecting buckle which is provided with a groove used for containing the can edge and the cover edge; the stud is in threaded connection with the upper end of the connecting buckle, and the lower end of the stud can be pressed on the upper end face of the cover edge; the bolt is fixedly arranged at the upper end of the cover edge, and the connecting buckle is movably arranged on the bolt in a sleeving mode. The connecting buckle comprises a first connecting piece, a second connecting piece and a third connecting piece; the first connecting piece, the second connecting piece and the third connecting piece jointly form a groove structure which is provided with an inward opening and used for containing the barrel edge and the cover edge. The barrel body and the cover body are connected and fixed more simply, conveniently and reliably.

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.