453 results about "River sand" patented technology

The invention discloses a preparation method of a modified reinforced recycled aggregate high-strength hydrophobic cement-based material, which comprises the following steps: (1) placing recycled concrete coarse aggregate in an acrylic acid solution for standing, separating out the coarse aggregate after standing, placing the coarse aggregate in modified slurry formed by calcined waste concrete micro powder, a silane coupling agent and water for coating, and drying to obtain the modified reinforced recycled aggregate high-strength hydrophobic cement-based material; and then separating out the coarse aggregate and drying to obtain the modified reinforced recycled aggregate. And (2) mixing cement powder, the modified reinforced recycled aggregate, river sand fine aggregate, filler powder and a water reducing agent, adding water, and uniformly stirring to obtain the maritime work cement-based material. According to the invention, the recycled concrete aggregate is modified and reinforced by using the concrete waste generated by the commercial mixing station, and a hydrophobic anti-seepage system is constructed in the concrete material, so that the strength and the water seepage resistance of the concrete material are effectively improved, and the concrete material can better adapt to the application in the marine environment.

The invention relates to the field of concrete prefabricated parts, and particularly discloses concrete for prefabricated parts and a preparation method of the concrete. The concrete for the prefabricated part is prepared from 350 to 380 parts of cement, 820 to 860 parts of river sand, 850 to 960 parts of tough epoxy resin modified gravel, 130 to 150 parts of water, 45 to 55 parts of mineral powder, 25 to 35 parts of fly ash, 8.3 to 9.0 parts of a water reducing agent, 5 to 10 parts of a molecular sieve carrier polyamide curing agent, 5 to 10 parts of composite expanded particles and 5 to 10 parts of modified fibers, the preparation method comprises the following steps: uniformly mixing the cement and the river sand, adding the mineral powder and the fly ash, and uniformly mixing to obtain a primary mixture; uniformly mixing the tough epoxy resin modified macadam with a molecular sieve carrier polyamide curing agent, adding the composite expanded particles, and uniformly mixing to obtain a composite material; adding the composite material and the modified fiber into the primary mixture, finally adding water and a water reducing agent, and uniformly mixing to obtain a mixture; and pouring and maintaining to obtain a finished product. The material has the advantages of high strength and difficulty in generating cracks.

The invention belongs to the technical field of building materials, and discloses an early-strength polymer modified cement-based grouting material and a preparation method thereof. The grouting material disclosed by the invention is prepared from the following raw materials in parts by weight: 100 to 115 parts of a cementing material, 100 to 115 parts of river sand, 20 to 23 parts of water, 2 to 2.5 parts of a water reducing agent, 0.02 to 0.04 part of an expanding agent, 0.22 to 1.76 parts of an acrylic emulsion and 0.04 to 0.08 part of a de-foaming agent, wherein the cementing material comprises 71-81 parts of Portland cement, 9-19 parts of sulphoaluminate cement, 6-8 parts of silica fume and 11-15 parts of fly ash microbeads. The early-strength, high-strength and high-fluidity cement-based grouting material can be obtained under the conventional curing condition by adopting the combined action of the acrylic emulsion polymer, the Portland cement and the sulphoaluminate cement, the plastic expanding agent, the polycarboxylate superplasticizer and the defoaming agent, and has good economic benefits and practical values.

The invention discloses a high-salt-corrosion-resistant concrete pouring material and a preparation method thereof, and relates to the technical field of high-salt-corrosion-resistant concrete, and the high-salt-corrosion-resistant concrete pouring material comprises the following components in parts by weight: 5-10 parts of modified charcoal, 1.5-3 parts of a corrosion inhibitor, 320-360 parts of cement, 650-700 parts of river sand, 20-30 parts of silica fume, 0.3-0.6 part of super absorbent resin, and 0.2-0.8 part of a water reducing agent. According to the high-salt-corrosion-resistant concrete pouring material and the preparation method thereof, a protective film is formed on the surface of a reinforcing steel bar through the corrosion inhibitor, the anodic oxidation reaction is inhibited, the reinforcing steel bar is prevented from being corroded, eugenol releases corrosion inhibition molecules, a hydrophobic protective film is formed on the surface of the reinforcing steel bar, and electrochemical corrosion is inhibited; meanwhile, through the synergistic effect of a physical barrier and chemical passivation, the calcium-aluminum salt-eugenol composite corrosion inhibitor not only can block a corrosion path through physical film formation, but also can inhibit electrochemical reaction through chemical adsorption, so that the corrosion inhibition efficiency is improved.

The invention discloses quick-hardening high-strength lightweight aggregate concrete, which is prepared from the following raw materials: ordinary Portland cement, quick-hardening sulphoaluminate cement, a mineral admixture, silica fume, ceramsite, river sand, water and an additive, and the additive is a mixture of a water reducing agent, a slump retaining agent, a retarder, a thickening agent and an air entraining agent; after the ceramsite absorbs water and is saturated, the surface of the ceramsite is coated with a cementing material, and the cementing material is hydrated to form a slurry shell; ordinary Portland cement and quick-hardening sulphoaluminate cement are compounded, mineral admixtures and silica fume are doped, the early strength of the lightweight aggregate concrete can be improved, meanwhile, the development of later strength is guaranteed, a layer of slurry'shell 'is formed on the surface of ceramsite through the hydration effect of the cementing material, and the surface of the ceramsite is wrapped by the composite cementing material. According to the ceramsite wrapped with the ash, firstly, the strength of the ceramsite can be improved, and then the strength of the concrete is improved; 2, the water absorption and water return phenomena of the ceramsite can be avoided; and thirdly, the floating phenomenon of the ceramsite can be improved.

The invention discloses concrete suitable for a high-altitude large-temperature-difference environment, and belongs to the technical field of building materials. In order to solve the problems of insufficient durability and easy cracking of traditional concrete in high altitude areas due to large day and night temperature difference, the technical scheme provided by the invention is as follows: a cementing material is a composite system composed of Portland cement, fly ash and slag powder, is matched with 5-20mm continuous grading coarse aggregate and river sand with fineness modulus of 2.3-2.8, and is added with basalt fiber and polypropylene fiber; and an air entraining agent, a polycarboxylate superplasticizer and water. The concrete has excellent crack resistance, freezing and thawing resistance and thermal stability by optimizing aggregate gradation, introducing multi-scale fiber for reinforcement, regulating and controlling the hydration heat of a cementing material and matching with an additive in a specific proportion to improve the working performance. The concrete is suitable for engineering such as plateau bridges and tunnels, the service life of the structure can be remarkably prolonged, and the maintenance cost is reduced.

The invention discloses multi-scale hybrid fiber high-toughness concrete and a preparation method thereof. The multi-scale hybrid fiber high-toughness concrete is prepared from 155 to 165 parts by mass of water, 400 to 450 parts by mass of cement, 30 to 70 parts by mass of fly ash, 1000 to 1100 parts by mass of broken stone, 700 to 750 parts by mass of river sand, 0.65 to 0.75 part by mass of a water reducing agent, 390 to 500 parts by mass of steel fibers, 40 to 50 parts by mass of polypropylene crude fibers and 2 to 6 parts by mass of polypropylene fine fibers. The particle size of the broken stones is 5-10 mm; the steel fiber is an end hook steel fiber, and the diameter of the end hook steel fiber is 0.75 mm; the diameter of the polypropylene crude fiber is 0.75 mm; and the diameter of the polypropylene fine fiber is 0.2 mm. According to the invention, the problem that the existing hybrid fiber concrete is relatively low in breaking strength and toughness indexes is solved.

The invention relates to the technical field of concrete, in particular to high-performance conductive concrete with low doping amount of carbon fibers and a preparation method of the high-performance conductive concrete. The conductive concrete is prepared from the following raw materials in parts by weight: 66 to 68 parts of cement, 24 to 25 parts of fly ash, 10 to 12 parts of silica fume, 16.8 to 20.5 parts of mixing water, 70.2 to 72.8 parts of river sand, 0.035 to 0.437 parts of short carbon fibers, 7.8 to 11.7 parts of steel fibers, 0.15 to 0.2 part of hydroxyethyl cellulose, 0.315 to 0.42 part of a de-foaming agent, 1.255 to 1.575 parts of a water reducing agent and 35 to 40 parts of water. The steel fibers serve as a main frame of a conductive network in the concrete and are preliminarily lapped to form the conductive network, the frame lapped by the steel fibers is subsequently filled with the carbon fibers, a more complete conductive network is formed, low resistivity of the conductive concrete is guaranteed, and high mechanical performance of the conductive concrete is guaranteed.

The invention discloses sulfate-erosion-resistant metakaolin-slag-based geopolymer concrete, belongs to the technical field of concrete, and aims to solve the problems that the corrosion resistance of traditional silicate concrete is ineffective and the adaptability of conventional alkali-activated concrete is insufficient in a special environment. The concrete comprises the following components in parts by weight: 60-90 parts of a cementing material, 120-170 parts of aggregate, 15-30 parts of a composite activator, 2-8 parts of a function regulator and the like, the cementing material is prepared from nano TiO2 / KH-550 composite modified metakaolin, slag and silica fume-coal gangue powder-HAP composite powder; the aggregate comprises modified limestone macadam (soaked and dried by a sodium dihydrogen phosphate solution) and river sand; the composite exciting agent comprises water glass, sodium hydroxide, sodium pyrophosphate, propylene glycol and the like; the function regulator comprises superfine fly ash, a naphthalene water reducer, HPMC (Hydroxy Propyl Methyl Cellulose) and boric acid. Through the synergistic effect of the components, the sulfate corrosion resistance, the mechanical property and the environmental adaptation performance of the concrete are improved, and the concrete is suitable for engineering construction under the service environment of high-concentration sulfate and the like.

The invention provides anti-erosion hydraulic concrete and a preparation method thereof, and belongs to the technical field of concrete. The concrete comprises the following components: composite cement, high-activity nano-modified metakaolin, blast furnace slag powder, low-calcium fly ash, coarse aggregate, natural river sand fine aggregate, granite machine-made sand fine aggregate, an erosion inhibitor, a functional additive, an early-strength polycarboxylic high-performance water reducer, a composite air entraining agent and the like. The composite cement comprises sulphoaluminate cement, Portland cement and polymer waterproof mortar. The high-activity nano modified metakaolin is obtained by modifying metakaolin with an organic silicon-ZnO composite emulsion and then drying. The erosion inhibitor comprises organic carboxylate, a hydrophobic-crystallization complexing agent and a pH buffer type corrosion inhibitor. The functional auxiliary agent comprises an itaconic acid and acrylic acid copolymer, a JRY-F concrete waterproof agent and polyethylene glycol-400 dilaurate. The composite air entraining agent comprises liquid sodium abietate and sodium alpha-olefin sulfonate. Through component synergism, modification and grading, an anti-erosion barrier is constructed.

The invention relates to the field of building materials, and discloses high-toughness and high-energy-absorption polymer emulsion modified mortar and a preparation method thereof, and the mortar is composed of ordinary Portland cement, river sand, a polymer emulsion, water, an active admixture and chopped fibers. Wherein the polymer emulsion is selected from styrene-acrylic emulsion (SBR), ethylene-vinyl acetate (EVA), polyurethane emulsion or a combination thereof; the mixing amount is 5-20wt% of the mass of the cementing material. According to the invention, a viscoelastic network is formed in a cement matrix through the polymer emulsion, and the synergistic effect of the active admixture and the chopped fibers is combined, so that the bonding strength, the crack resistance, the impact resistance and the stress wave dissipation capability of the mortar are remarkably improved. Test results show that the mortar provided by the invention is obviously superior to ordinary mortar in the aspects of 28d breaking strength, impact toughness and stress wave attenuation performance, and is suitable for high-performance constructional engineering and protective engineering.

The utility model belongs to the technical field of river sand screening, in particular to a sand screening machine for hydraulic engineering, which comprises a drum sand screening machine and a river sand conveying belt, a river sand washing plate is arranged in the drum sand screening machine, a conveying water pipe is arranged above the river sand washing plate, a connecting hose is fixedly connected between the river sand washing plate and the conveying water pipe, and the connecting hose is connected with the drum sand screening machine. A water and sand feeding belt is installed below the drum sand screening machine, the top end of a water and sand feeding belt support is fixedly connected with a river sand filtering belt, and the inner wall of the drum sand screening machine is fixedly connected with a water body intercepting ring; river sand at the tail end of the drum sand screening machine can be washed through a river sand washing plate, a conveying water pipe and a connecting hose, impurities and the river sand attached to the surface of a filter screen of the drum sand screening machine can be removed in cooperation with interception of a water body interception ring on the water body, and the river sand is impacted by water flow to penetrate through the filter screen of the drum sand screening machine; and a water and sand feeding belt and a river sand filtering belt are matched to secondarily filter the river sand mixed with the water body, so that the screening effect on the river sand can be greatly improved.

The invention discloses a high-resolution seismic sequence division method for a river channel sand group, and relates to the technical field of petroleum and natural gas exploration and development. According to the method, a high-resolution sequence stratigraphy theory is taken as guidance, a flooding mudstone interface is taken as a marker bed, a high-density isochronous slice highly matched with seismic data is obtained, and an isochronous stratigraphic interface identification mark is constructed according to sand body development characteristics, so that the multiplicity of solution division of fluvial facies sand group seismic sequences is effectively reduced. According to the method, on the basis of isochronous stratigraphic division, the division scheme is adjusted according to the actual seismic homonymous axis form and the characteristics of the sand body on the well, the unit division result is more objective and fine, and therefore the method can be widely applied to seismic stratigraphic division of the fluvial facies sand group.

The invention relates to the technical field of fluid-state solidified soil, and particularly discloses high-fluid-state solidified soil and a preparation method thereof. The high-flow-state solidified soil is prepared from the following raw materials in parts by weight: 1100 to 1200 parts of recycled aggregate, 700 to 800 parts of river sand, 100 to 130 parts of a curing agent, 18 to 22 parts of a polycarboxylic acid water reducing agent, 75 to 85 parts of solidified soil repairing microcapsules and 55 to 95 parts of water, the solidified soil repairing microcapsule is prepared by taking polylactic acid and nano calcium carbonate grafted polyethylene glycol as composite membrane materials, and wrapping and forming sulphoaluminate cement paste through an emulsification-solidification method. The solidified soil repairing microcapsules are introduced into the solidified soil, pores in an interface transition area can be filled, micro cracks can be repaired, and the durability of the solidified soil is improved.

The invention relates to the technical field of solid waste resource utilization, in particular to an alkali-activated all-solid waste cementing mortar material and a preparation method thereof.The alkali-activated all-solid waste cementing mortar material is prepared from, by weight, 10-40 parts of aluminum mud subjected to low-temperature thermal activation, 3-5 parts of an alkali activator, 20-45 parts of mineral powder, 30-60 parts of silica fume or fly ash, river sand and water; the alkaline activator comprises water glass and sodium hydroxide; the alkali-activated all-solid waste cementing mortar is a novel inorganic material which is green, pollution-free and durable, the pretreatment of solid waste is simple, the preparation method of the cementing material is simple, the strength can be rapidly improved only through reasonable maintenance, and the construction cost is reduced. In other aspects, such as mechanical properties, stability, corrosion resistance and high temperature resistance, the requirements of building materials can be met, and the market prospect is relatively great.

The application belongs to the field of concrete production, and particularly relates to a preparation process for improving the performance of machine-made sand concrete, which comprises the following specific steps: S1: taking ether water-reducing agent, ether slump-retaining water-reducing agent, retarder, mud inhibitor and water in a proportion of 160:35:20:5:780 respectively, and compounding the above-mentioned materials to obtain a composite admixture; S2: taking 585 parts of machine-made sand and cleaning the machine-made sand by using a cleaning device, then drying the cleaned machine-made sand, and then mixing the treated machine-made sand with 200 parts of fine river sand, 25 parts of red mud and 1050 parts of stone for 30-50 seconds to obtain a mixture A; S3: taking 60 parts of fly ash, 60 parts of mineral mud and 240 parts of cement, and adding the mixture A to obtain a mixture B after stirring and mixing for 40-50 seconds; the composite admixture is obtained by compounding the above-mentioned materials in a proper proportion, and the machine-made sand concrete is prepared by using a proper proportion, so that the slump retention performance of the concrete is improved, and the final setting time of the concrete is not greatly affected.

The invention relates to the technical field of concrete 3D printing, in particular to modified alkali-resistant regenerated glass fiber reinforced concrete and a preparation process thereof, and the modified alkali-resistant regenerated glass fiber reinforced concrete is prepared from the following components in parts by weight: 600-650 parts of cement, 90-100 parts of fly ash, 30-35 parts of silica fume, 500-600 parts of river sand, 0.5-6 parts of modified alkali-resistant regenerated glass fibers, 10-15 parts of a water reducing agent and 120-200 parts of water. According to the invention, the regenerated glass fiber obtained by recovering the waste fan blades is used as a reinforcing material of the concrete, so that the resource consumption can be effectively reduced, and the carbon emission is reduced; the invention provides a surface modification method aiming at regenerated glass fibers, so that the long-term durability of the regenerated glass fibers in an alkaline cement matrix is enhanced, the generation of microcracks on a fiber and cement interface is reduced, and the constructability and excellent mechanical properties of the 3D printing concrete are improved. The method not only meets the requirements of digital and intelligent transformation and upgrading of the building industry, but also provides a new method for recycling of waste resources and sustainable development of the building industry, and has relatively high economic and environmental benefits.

The invention relates to the technical field of material performance detection, and discloses a non-destructive evaluation method and system for the strength of microorganism mineralized river sand, and the method comprises the following steps: applying a sweep frequency sound wave excitation signal to a microorganism mineralized river sand standard sample model; performing penetration simulation operation on the microorganism mineralized river sand standard sample model according to the sweep frequency sound wave excitation signal; extracting mineralization specific characteristic parameters corresponding to the sample model through the penetration response signal; according to the mineralization specificity characteristic parameters, constructing a biological cementation index of microorganism mineralization, and according to the biological cementation index, analyzing the compressive strength of the microorganism mineralization river sand standard sample model; constructing a destructive calibration curve of the microorganism mineralized river sand standard sample model; the target compressive strength of the to-be-tested sample model is analyzed through the destructive calibration curve, and the strength non-destructiveness of the microorganism river sand corresponding to the to-be-tested sample model is analyzed based on the target compressive strength. According to the method, the accuracy of non-destructive evaluation of the strength of the microorganism mineralized river sand can be improved.

The invention relates to a preparation technology of a cement-based repairing material, and aims to provide a double-component high-strength repairing mortar material and a preparation method thereof. The repairing mortar material comprises two components: a component A, a component B and a component C, wherein the component A is composed of modified cement, sulphoaluminate early strength cement and water-based resin; the component B is prepared from silica fume, silane, cellulose ether, redispersible latex powder, short fibers, a polycarboxylic acid water reducing agent and a defoaming agent; and river sand with the same amount as the component A can be further included. The silicane is used for modifying the silica fume, and a silanol group and a silicon hydroxyl group on the surface of the silica fume are subjected to dehydration condensation to form a stable Si-O-Si covalent bond, so that the adsorbability of the modified silica fume to water is reduced, and the risk of cracking of the repair mortar is avoided. The component B can be used as an auxiliary component for curing the water-based resin in the component A to control the setting time of the repair mortar, improve the early strength of the mortar added with the water-based resin and improve the weather resistance of the water-based resin; the overall strength of the mortar can be improved, and the production cost of the repairing mortar is reduced.

The invention discloses polymer-based anti-crack concrete and a preparation method thereof, and relates to the technical field of concrete. When the polymer-based anti-crack concrete is prepared, acrylic acid is grafted on the surfaces of pretreated polypropylene particles to prepare modified polypropylene particles; coating sodium metasilicate with sodium alginate to prepare a self-repairing microcapsule; the preparation method comprises the following steps: hydrolyzing 3-glycidyl ether oxypropyl trimethoxy silane, and grafting the hydrolyzed 3-glycidyl ether oxypropyl trimethoxy silane on the surface of silicon dioxide to prepare modified silicon dioxide; mixing the modified polypropylene particles, basalt fibers and polyacrylonitrile fibers to obtain a solid functional component; cement, slag powder, silica fume, an expanding agent, a solid functional component, modified silicon dioxide, a water reducing agent, an air entraining agent, deionized water, river sand, gravel and the pre-wetted self-repairing microcapsule are mixed, and the polymer-based anti-crack concrete is prepared. The polymer-based anti-crack concrete prepared by the invention has excellent anti-crack, freeze-thaw-resistant and self-repairing properties.

The invention discloses a high-strength anti-crack concrete material and a preparation method thereof, and relates to the technical field of concrete. The prepared high-strength anti-crack concrete material is prepared from Portland cement, river sand, modified basalt fibers, modified polyacrylonitrile fibers, a defoaming agent, a water reducing agent and fly ash. The modified basalt fiber is obtained by reacting pretreated basalt fiber with 4-amino-2-tert-butylphenol and then reacting with 2-pyrazinyl ethanethiol, and the modified basalt fiber is obtained; the modified polyacrylonitrile fiber is obtained by reacting hydrolyzed polyacrylonitrile fiber with thiosemicarbazide, then reacting with 2, 4-difluorobromoacetophenone, then reacting with phosphorus oxychloride and N 'N-dimethylformamide, and then cross-linking with 5, 5'-diamino-2, 2 '-dipyridyl, and the modified polyacrylonitrile fiber is obtained by the following steps: reacting hydrolyzed polyacrylonitrile fiber with thiosemicarbazide, reacting with 2, 4-difluorobromoacetophenone, reacting with phosphorus oxychloride and N' N-dimethylformamide, and cross-linking with 5, 5 '-diamino-2, 2'-dipyridyl. The prepared high-strength anti-cracking concrete material has high strength, anti-aging performance and antibacterial performance.

The invention discloses a geopolymer-based recycled fine aggregate shield synchronous grouting material and a preparation method thereof. The grouting material is composed of a cementing material, an alkali activator, aggregate, a water reducing agent, a retarder and water, and the cementing material is a geopolymer precursor and is composed of fly ash, slag and metakaolin; the aggregate is composed of river sand and recycled fine aggregate. By optimizing the proportion and the preparation process, the material has the characteristics of excellent flowability, controllable setting time, high early strength, good impermeability, good durability and the like, and is suitable for synchronous grouting of shield tunnels in water-rich sand layers, high-water-pressure stratums or corrosion stratums. The invention also provides two optimization methods which are respectively based on a response surface method and a BP neural network combined genetic algorithm to realize multi-objective optimization of slurry performance. According to the material, dependence on traditional cement and gravel resources is remarkably reduced, energy consumption and carbon emission are reduced, high-added-value resource utilization of industrial solid waste and construction waste is achieved, and the material conforms to the development direction of green low-carbon building materials.

The invention relates to the technical field of cement preparation, and provides concrete containing solid waste and a preparation technology thereof.The preparation technology of the concrete containing the solid waste comprises the following steps that cement and waste concrete powder are put into a stirring machine, dry mixing is conducted for 1-2 min till the mixture is uniform, then river sand, natural gravel and construction waste gravel are added, dry mixing continues for 3-4 min, and the mixture is stirred to be uniform; and slowly adding a polycarboxylic acid water reducing agent and deionized water, carrying out wet mixing for 1-2 min, adding the composite fibers into the mixer in batches, continuing to carry out mixing for 3-5 min, and carrying out curing so as to obtain the concrete. Chitosan fibers are subjected to chemical modification treatment and compounded with steel fibers according to a specific proportion, and the compound is used as a reinforcing component to be introduced into a concrete system; the microstructure of the concrete is effectively optimized, the mechanical property and crack resistance of the material are remarkably improved, and meanwhile resource utilization of solid waste is achieved.

The invention relates to environment-friendly concrete based on building waste and a production method. The environment-friendly concrete is prepared from the following raw materials: cement, river sand, modified regenerated building waste, fly ash, water, a water reducing agent, epoxy resin and an alcohol amine compound. Wherein the modified regenerated building waste is obtained by sequentially carrying out carbonization treatment on regenerated building waste, immersing the regenerated building waste into a nano silicon dioxide aqueous dispersion liquid for freezing and melting circulation treatment and carrying out surface amination treatment. The internal structure of the regenerated building waste is optimized, so that the strength of the regenerated building waste is improved, the high-strength, low-bleeding and environment-friendly concrete material is developed, and recycling of the regenerated building waste is promoted.

The utility model discloses a rail push-pull type covering electric heating hotbed which comprises an electric heating hotbed body and a push-pull type covering device. The electric heating hotbed main body comprises an extruded sheet, river sand is paved below the extruded sheet, geothermal wires are uniformly distributed above the extruded sheet, and two ends of the geothermal wires are connected with an automatic temperature controller through power inlets to form a closed circuit; river sand and non-woven fabric are uniformly covered on the terrestrial heat lines, and hole trays for seedling raising are placed on the terrestrial heat lines The push-pull type covering device comprises a groove type seedbed frame, an outer side rail bottom plate, a pulley assembly and an arch bar, and the pulley assembly comprises a rail and a pulley; the arch bars comprise the inner side covering arch bars and the outer side covering arch bars, the center vertical height of the inner side covering arch bars is smaller than that of the outer side covering arch bars, the inner side covering arch bars move on the rails at the top ends of the groove type seedbed frames through the pulleys, and the outer side covering arch bars move on the rails of the outer side rail bottom plates through the pulleys. The device is suitable for plant varieties of various out-of-season heating seedbed seedling raising, the seedling condition is good, the seedling raising efficiency is high, and operation is convenient.

The invention relates to a microwave curing concrete based on carbon mineralization wave-absorbing functional aggregate and a preparation method thereof, the microwave curing concrete comprises the following raw materials by weight: 350-400 parts of cement, 40-50 parts of fly ash, 40-50 parts of silica fume, 530-903 parts of carbon mineralization wave-absorbing functional aggregate, 0-414 parts of gravel, 691-712 parts of river sand, 1.5-3.0 parts of a water reducer, 12-20 parts of a nano magnetic fluid functional component, and 134-183 parts of water. Through composite application of the carbon mineralization wave-absorbing functional aggregate and the nano-magnetofluid functional component, the carbon mineralization wave-absorbing functional aggregate mainly provides skeleton type macroscopic wave absorption, the nano-magnetofluid functional component provides diffuse type nano-scale wave absorption, and the carbon mineralization wave-absorbing functional aggregate and the nano-magnetofluid functional component jointly construct an efficient and uniform microwave absorption network on different scales. The microwave energy utilization rate is obviously improved, the microwave curing performance of the concrete can be effectively improved, and the early mechanical property, the long-term strength and the durability of the concrete are improved.

The invention discloses a coal gasification ash-based roadway bottom plate filling material and a construction method, and belongs to the technical field of coal-based solid waste resource utilization. According to the bottom plate filling material, coal gangue serves as coarse aggregate, natural river sand and coal gasification ash coarse slag serve as fine aggregate, the coal gasification ash fine slag is activated to serve as a cementing material, and the optimal proportion of the filling material required by bottom plate filling is determined through a design test. According to the method, firstly, the position where the roadway bottom plate is prone to instability is determined through numerical simulation, bottom plate filling construction is conducted, roadway stability can be maintained in a more targeted and emphasized mode, the setting speed of the bottom plate filling material can be increased by adding the accelerator into the filling material, the filling efficiency is improved, and the filling efficiency is improved. Meanwhile, coal gangue and coal gasification ash are selected as filling raw materials, efficient disposal and utilization of mine solid waste materials are achieved, and the material has the advantages of being low in cost, high in strength, short in setting time and the like and meets the requirement of serving as a bottom plate filling material.

The invention relates to self-compacting micro-expansive high-volume-weight concrete and a preparation method thereof, and the self-compacting micro-expansive high-volume-weight concrete comprises the following components in parts by weight: 240-400 parts of cement, 80-150 parts of fly ash, 30-100 parts of silica fume, 20-60 parts of a rheology modified material, 20-60 parts of an expanding agent, 50-150 parts of an internal curing agent, 600-900 parts of fine aggregate, 800-1200 parts of coarse aggregate, 140-260 parts of water and 5-12 parts of an additive, the rheology modified material comprises glass beads, cellulose ether and polycarboxylic acid ether, and the mass ratio of the glass beads to the cellulose ether to the polycarboxylic acid ether is 1: (0.1-0.3): (0.001-0.01); the expanding agent comprises calcium oxide and active magnesium oxide; the internal curing agent comprises natural zeolite and zeolite powder; the fine aggregate comprises river sand and iron tailings; the coarse aggregate comprises broken stones and iron tailings. The problem of restriction among the volume weight, the volume stability and the working performance of the concrete in related technologies can be solved, so that the self-compaction, micro-expansion and high volume weight functions of the concrete are realized.

The invention discloses fly ash-based geopolymer concrete and a preparation method thereof, and the fly ash-based geopolymer concrete is prepared from the following raw materials in parts by mass: a solid waste cementing material including 60-70 parts of fly ash and 15-30 parts of slag; 2-8 parts of a solid alkali activator; 3-6 parts of carbide slag; the aggregate is prepared from 100 to 120 parts of river sand and 240 to 260 parts of gravel; and 30-45 parts of water. According to the fly ash-based geopolymer concrete disclosed by the embodiment of the invention, carbon dioxide generated in the process of preparing a cementing material can be reduced or avoided, the production cost and the environmental load of the concrete are reduced, the potential activity of the coal-based solid waste can be fully exerted, and meanwhile, the efficient utilization of the fly ash is realized; by introducing the carbide slag and the solid alkali activator, the activity of the fly ash and the slag can be activated, an alkaline environment can be provided, active SiO2 and Al2O3 in the fly ash are subjected to a hydration reaction, hydration products such as C-S-H gel are continuously generated, and the long-term performance of the concrete is more stable.

The invention relates to a high-strength MICP reinforced SiO2 aerogel concrete composite material and a preparation method thereof.The method comprises the steps that cement, river sand, pebbles, silicon dioxide aerogel particles and water are added into a stirrer according to the proportion and stirred for 2-3 min till even mixing is achieved, and aerogel concrete slurry is obtained; continuously adding water into the aerogel concrete slurry, stirring for 3-5 minutes until viscous slurry is formed, sequentially adding a bacterial liquid, a saturated urea solution and a saturated calcium chloride solution according to a ratio, and stirring for 2-3 minutes until microorganisms are uniformly distributed to obtain a uniform mixture with the fluidity reaching the standard; and pouring the mixture into a mold, vibrating until bubbles are discharged, transferring the mold into a constant-temperature and constant-humidity curing chamber, and curing to obtain the aerogel concrete composite material. The method is simple in process, the heat conductivity coefficient of the concrete material can be remarkably reduced, and the compressive strength is improved; the prepared concrete composite material has the characteristics of self-repairing and heat-insulating functions, high compressive strength and the like.