59 results about "Air content" patented technology

The invention relates to the technical field of concrete admixtures, in particular to an air-entraining type polycarboxylate superplasticizer and a preparation method thereof. The air-entraining type polycarboxylate superplasticizer is formed by polymerizing a polyether macromonomer, a modified active agent and first unsaturated acid through a free radical polymerization reaction, the preparation method comprises the following steps: carrying out condensation reaction on a surfactant, a condensing agent and second unsaturated acid at 60-80 DEG C for 2-3 hours, and removing water in the condensation reaction to obtain the modified active agent. According to the air-entraining type polycarboxylate superplasticizer prepared by the invention, the modified active agent is introduced into the molecules of the air-entraining type polycarboxylate superplasticizer, the adsorption capacity of the polycarboxylate superplasticizer and cement and the specific surface tension of a hydration film are adjusted by utilizing different HLB (Hydrophile-Lipophile Balance) values of the modified active agent, and meanwhile, the flowability of concrete and the air content of the concrete are improved; therefore, the concrete slump rewinding emptying time is shortened, and the concrete compressive strength is kept at a certain good level.

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 provides anti-freezing and anti-cracking concrete. The anti-freezing and anti-cracking concrete is prepared from the following components in parts by weight: 1500 to 2000 parts of coarse aggregate, 800 to 1100 parts of fine aggregate, 300 to 450 parts of water, 120 to 170 parts of admixture, 50 to 70 parts of bonding enhancer, 25 to 36 parts of air content agent, 17 to 22 parts of water reducing agent and 12 to 16 parts of fiber enhancer. The bonding enhancer is added into the raw materials of the concrete, so that the bonding performance and crack resistance of the concrete can be improved, the cohesive force of the concrete is enhanced, the cracking risk is reduced, the air content agent can form tiny bubbles in the concrete, and the bubbles can absorb freeze-thaw water and reduce the frost heaving pressure; the water reducing agent can improve the flowability and the working performance of the concrete and reduce pore structures in the concrete at the same time, fiber reinforced materials such as polypropylene fibers or steel fibers are added, the crack resistance and the toughness of the concrete can be remarkably improved, and the fibers can bear part of tensile force, so that the anti-freezing performance and the anti-cracking performance of the concrete are improved. And the cracking possibility is reduced.

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.

Properly adjust the composition of the air inside the cabinet [Solution] An air composition adjustment device (90) adjusts the composition of inside air inside a storage cabinet (2). The air composition adjustment device (90) includes a composition adjustment section (100), an air supply section (40), a detector (160), and a controller (110). The composition adjustment section (100) supplies a gas to be treated, the gas having a composition different from that of the outside air, to the storage cabinet (2). The air supply section (40) supplies the outside air to the storage cabinet (2). The detector (160) detects the concentrations of components of the inside air. The controller (110) adjusts the flow rate of the outside air supplied to the storage cabinet (2) by the air supply section (40) based on the value detected by the detector (160).

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.

The invention relates to the technical field of engineering construction, in particular to a building solid waste-based cement mortar strength prediction method based on multi-element factor fitting. According to the method, the relation between the cement component proportion, the gelation and porosity ratio and the strength of the set cement is measured through a formulating method, and a mathematical model of the relation between factor variables such as the strength of the set cement, the crushing value of the solid waste fine aggregate, the content of solid waste fine powder, the bad grain shape of the solid waste fine aggregate, the volume ratio of the fine aggregate, the surface area of the fine aggregate, the slurry bone interface and the gas content and the strength is established; therefore, the mortar strength is measured and calculated, solid waste-based cement mortar mix proportion optimization design and preparation are achieved, strength quality prediction evaluation and preparation adjustment are achieved according to tailings of different qualities and multi-factor diversified fluctuation in actual production, solid waste is reasonably utilized, and the solid waste-based cement mortar engineering quality is guaranteed.

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.

The invention relates to the technical field of additives for cement concrete, in particular to a polycarboxylic acid additive and a preparation method and application thereof.The polycarboxylic acid additive is prepared from a polymeric base material, a material A and a material B. The polymeric base material comprises a macromonomer, 2-acrylamide-2-methylpropanesulfonic acid, part of a first comonomer and water, the material A comprises an initiator, a molecular weight regulator and water, and the material B comprises residual first comonomer, second comonomer and water; the first comonomer comprises any one or two of acrylic acid and methacrylic acid; the second comonomer is a mixture of hydroxypropyl acrylate and hydroxyethyl acrylate. The polycarboxylic acid admixture integrates the functions of water reduction, delayed coagulation and air entraining, is very high in water-reducing rate, high in compressive strength ratio, proper in air content, good in workability maintaining effect of a roller compacted concrete mixture, good in delayed coagulation effect, reasonable in initial and final setting time distribution and convenient to construct, and solves the problems faced by roller compacted concrete at present.

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 a concrete quality obtaining method and device and a computer readable storage medium. The concrete quality obtaining method comprises the steps that initial parameters of target concrete and transportation process parameters related to the quality of the target concrete in the process of transporting the target concrete through a transport vehicle are obtained; the initial parameters comprise the initial compressive strength of the target concrete, the initial workability of the target concrete and the setting time of the target concrete; the transportation process parameters comprise at least one of the following parameters: the temperature of the target concrete, the air content in the target concrete, the transportation time, the stirring time of the target concrete in a transport vehicle, the power of a roller motor of the transport vehicle and the slump of the target concrete; and inputting the initial parameters and the transportation process parameters into a preset concrete quality evaluation model to obtain a quality evaluation result of the target concrete. According to the scheme, quality evaluation can be carried out on the concrete transported to the construction site, and a relatively accurate quality evaluation result is obtained.

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.

The utility model discloses a box-type gastrodia elata planting device, which relates to the technical field of gastrodia elata planting and comprises a support and a box. The box body is movably connected with the support, a plurality of bosses are arranged at the bottom of the inner wall of the box body and are of hollow structures, a plurality of air nozzles are arranged on the outer sides of the bosses, an air blowing assembly is arranged at the bottom of the box body and used for supplying air to the bosses, and a vibration assembly is arranged between the support and the box body. The vibration assembly is used for generating vibration to loosen soil. The boss with the air tap is arranged in the soil in the box body, air can be blown out through the air tap in the growth process of gastrodia elata, the air content in the soil is higher, meanwhile, an air flow channel can be generated in the soil, the soil is loosened, the vibration assembly is arranged in a matched mode, the soil can be vibrated to be loosened, and therefore the gastrodia elata planting efficiency is improved. Furthermore, the soil environment for planting the gastrodia elata can be relatively loose.