930 results about "Metakaolin" patented technology

The invention belongs to the technical field of building materials, and discloses a high-activity composite auxiliary cementing material based on carbonated steel slag-carbide slag as well as a preparation method and application of the high-activity composite auxiliary cementing material. The high-activity composite auxiliary cementing material is prepared from the following raw materials in parts by mass: 40 to 55 parts of carbonated steel slag-carbide slag composite micro powder, 30 to 40 parts of high titanium slag, 20 to 25 parts of metakaolin, 3 to 5 parts of ardealite, 3 to 5 parts of calcium carbonate, 3 to 5 parts of calcium carbonate and 3 to 5 parts of calcium carbonate. Wherein the carbonated steel slag-carbide slag composite micro powder is obtained by carrying out carbon sequestration reaction on steel slag and carbide slag in a solution consisting of a carbonization enhancer, an additive and water. On one hand, the CO2 storage amount of the steel slag and the carbide slag is increased, the stability and the activity are improved, on the other hand, the carbonized steel slag-carbide slag and other industrial solid waste are cooperated to achieve a composite superimposed effect, the cement mortar or the concrete can be improved in strength, stability and durability, the comprehensive performance is good, and the cost is low. And the method is green, low-carbon, energy-saving, environment-friendly and wide in popularization and application

The invention discloses a sulfur-manganese composite autotrophic denitrification filler as well as a preparation method and application thereof, and belongs to the technical field of environmental functional materials and polluted water treatment. The sulfur-manganese composite autotrophic denitrification filler contains manganese salt, a sulfur-based component and a cement-based component, the manganese salt comprises one or more of manganese carbonate, calcium manganese ore and rhodochrosite; the sulfur-based component comprises sulfur and sulfur manganese ore; the cement-based component comprises cement, fly ash pottery sand, silica fume, blast furnace slag and metakaolin; the cement comprises one or more of Portland cement, iron aluminate cement and sulphoaluminate cement. The nitrogen removal efficiency of the sulfur-manganese composite autotrophic denitrification filler is superior to that of a sulfur autotrophic denitrification system, the sulfate concentration and nitrite nitrogen accumulation in effluent are remarkably reduced, the service life of the filler is prolonged, and the efficient utilization rate of the material is improved.

The invention relates to the technical field of filling materials, and particularly discloses an ardealite-based high-strength anti-seepage filling material and a preparation process thereof, the ardealite-based high-strength anti-seepage filling material comprises 50%-65% of pretreated ardealite, 15%-25% of Portland cement, 5%-15% of superfine slag powder, 5%-10% of electrolytic manganese residues, 5%-8% of silica fume, 3%-6% of metakaolin, 2%-4% of a composite alkali activator and 0.5%-1.2% of a polycarboxylic acid water reducer, 0.3%-0.8% of an organic silicon water repellent and 0.05%-0.1% of cellulose ether; according to the invention, through chemical reaction of Mn < 2 + > in the electrolytic manganese residue and SO4 < 2-> in the phosphogypsum, micron-sized manganite crystals (MnAl2 (SO4) 4. 22H2O) are generated to actively fill internal micro-cracks of the material, so that a filling body is endowed with a self-repairing function and the impermeability is improved, and a composite alkali activator composed of NaOH and water glass is used for synergistically activating potential gelling activity of the superfine slag powder and the silica fume, so that the self-repairing filling material is prepared. And the formation of hydration products is accelerated, and 0.3-0.5 T of pulsed magnetic field is applied in the stirring process, so that the manganite crystals are guided to orderly grow along the expected stress direction of the filling body, and the compressive strength is improved.

A corrosion-resistant material for a cement slurry, a carbon dioxide corrosion resistant cement slurry, a preparation method, and a use. The corrosion-resistant material comprises a mixture A and a mixture B, wherein the mixture A comprises activated carbon, nanosilicon dioxide, and nano-alumina; the mixture B comprises a component C and a component D; the component C is selected from diatomite and / or fly ash; and the component D is selected from one or more of metakaolin, pumice, and coal gangue. The carbon dioxide corrosion resistant cement slurry made of the corrosion-resistant material has good corrosion resistance in a CO2 corrosion environment; the cement stone before corrosion has a high compressive strength and a compact structure; and the cement stone after corrosion has good comprehensive properties, for example, has no obvious decrease in compressive strength, small permeability, good mechanical properties, good settling stability, and good rheology, such that the cementing quality of a CCUS well is guaranteed, and efficient storage of CO2 is achieved.

The invention provides an ultrahigh-ductility cement-based composite material for ocean engineering and a preparation method of the ultrahigh-ductility cement-based composite material for ocean engineering. The concrete is prepared from the following raw materials in parts by weight: 250 to 500 parts of cement clinker, 400 to 600 parts of fly ash, 200 to 300 parts of mineral powder, 100 to 150 parts of silica fume, 160 to 240 parts of metakaolin, 600 to 900 parts of quartz sand, 10 to 20 parts of organic synthetic fiber, 20 to 30 parts of organic corrosion inhibitor, 180 to 240 parts of water and 1 to 8 parts of water reducing agent. The organic corrosion inhibitor provided by the invention can be combined with chloride ions to form a passive film, so that the corrosion of reinforcing steel bars and the invasion of the chloride ions into concrete are inhibited, and the durability of the concrete is improved; by regulating and controlling the mixing ratio of the four mineral admixtures and the mixing amount of the synthetic fiber component, the concrete can well consider high strength, high ductility, high durability, high flow state and excellent deformation resistance. The ultrahigh-ductility concrete for ocean engineering, which can meet the toughness requirements of high compression resistance, fracture resistance and impact resistance and the requirements of high chloride ion permeation resistance and steel bar corrosion resistance, can be obtained.

The invention belongs to the technical field of new building materials, and provides a low-alkalinity and early-strength ardealite filling and curing material and a preparation method thereof.The low-alkalinity and early-strength ardealite filling and curing material is prepared from ardealite, a curing agent and water, the curing agent comprises silica fume, limestone powder, superfine granulated blast furnace slag powder, metakaolin, calcium aluminate powder, Portland cement clinker powder, a suspension stabilizer and hydroxypropyl methyl cellulose ether. The problems of delayed coagulation, low early strength and high alkalinity of a common cement-based ardealite filling material can be solved, and the technical requirements of ardealite cemented filling are met.

The invention belongs to the field of modified self-repairing calcium aluminate cement 3D printing, and particularly relates to a phosphate modified self-repairing calcium aluminate cement 3D printing material and a preparation method thereof. The phosphate modified self-repairing calcium aluminate cement 3D printing material prepared by the invention is prepared from the following raw materials in parts by mass: 60 to 70 parts of calcium aluminate cement, 3 to 7 parts of silica fume, 2 to 4 parts of metakaolin, 0.5 to 3.5 parts of double-template modified calcium bentonite, 0.8 to 1.5 parts of amino modified sodium polyphosphate and 0.15 to 0.8 part of basalt fiber. The invention relates to a concrete anti-microbial agent, which is prepared from the following raw materials in parts by weight: 20-30 parts of water, 20-30 parts of water, 20-30 parts of water, 20-30 parts of nano calcium carbonate, 20-30 parts of nano calcium carbonate, 20-30 parts of magnesium phosphate cement coated bacteria-loaded porous microspheres, 20-30 parts of a polycarboxylate superplasticizer, 20-30 parts of an organic silicon defoaming agent and 25-35 parts of mixing water. The technical-economic cooperation requirement of building 3D printing under complex working conditions is met, and various indexes of phosphate modified calcium aluminate cement applied to the 3D printing technology are met.

The invention discloses high-strength concrete and a preparation method thereof in the field of concrete. The high-strength concrete is prepared from the following raw materials in parts by weight: superfine sulphoaluminate cement; coarse aggregate; quartz sand; silica fume; coal ash; nano metakaolin; silicon carbide whiskers; a graphene oxide; a pH responsive microcapsule; coating the steel fibers with liquid metal; a carbon nanotube; and a polycarboxylic acid water reducer. Release of the repairing agent is accurately regulated and controlled by adopting the pH response microcapsule, the interface performance is enhanced by combining with the liquid metal coating steel fiber, and the composite dispersion process of the nano material is optimized. Wherein the environment response efficiency of the microcapsule is remarkably improved through the collaborative design of a calcium oxide-slow release agent system and a methyl methacrylate / acrylic acid copolymerization shell layer; according to the gallium-based liquid metal coating, metallurgical bonding of fibers and a matrix is achieved through the low-melting-point characteristic, and traditional physical bonding limitation is broken through.

The invention relates to hybrid fiber reinforced ultrahigh-performance geopolymer concrete as well as a preparation method and application thereof. Slag, metakaolin and silica fume are used as precursor materials of geopolymer concrete, a sodium hydroxide-water glass solution is adopted to compound an alkali activator, and steel fibers, polyvinyl alcohol fibers and modified glass chopped fibers of different sizes are mixed and doped, so that the brittleness of the geopolymer concrete is remarkably improved, and the service life of the geopolymer concrete is prolonged. The early strength and the high temperature resistance are improved. The hybrid fiber reinforced ultrahigh-performance geopolymer concrete has the characteristics of low carbon emission, ultrahigh strength, high temperature resistance, high durability and the like, and can meet the use of the geopolymer concrete in actual engineering. According to the ultrahigh-performance geopolymer concrete, solid waste resources are utilized at the same time, carbon emission in the concrete production process is reduced, and the ultrahigh-performance geopolymer concrete is environmentally friendly, low in carbon, ultrahigh in strength, easy to prepare and capable of being suitable for complex environmental engineering structures such as tunnels, bridges and high-rise buildings.

The invention discloses high-performance fluid-state solidified soil for backfill based on composite ardealite of building residue soil, which is prepared by taking the building residue soil as a core raw material, taking a compound of a polycarboxylic acid water reducer and hydroxypropyl methyl cellulose as a fluidization regulator, and mixing the fluidization regulator and the building residue soil to prepare the high-performance fluid-state solidified soil for backfill. Superfine slag powder, fly ash, nano silicon dioxide, metakaolin and ardealite are used as curing agents, so that the fluid-state solidified soil with strong performance is obtained. Through the synergistic effect of all the components and innovative processes such as liquid nitrogen low-temperature grinding, nano material compounding and a segmented vacuum stirring process, the effect that the ultrahigh strength of the construction waste soil reaches 7.5 MPa within 14 days is achieved for the first time and is improved by 40% or above compared with that of conventional solidified soil, and the industrial problem that traditional waste soil is insufficient in solidification strength is solved; and collaborative optimization of strength and fluidity is realized. Meanwhile, efficient resource utilization of the construction waste is achieved, land occupation and environmental pollution caused by muck landfill are greatly reduced, and the requirement for green and sustainable development is met.

The invention belongs to the technical field of fireproof materials, and particularly relates to a non-intumescent fireproof coating for a fiber reinforced composite material as well as a preparation method and application of the non-intumescent fireproof coating. A binder in preparation raw materials of the non-intumescent fire retardant coating comprises metakaolin, fly ash, CA80 high-alumina cement and an exciting agent, or comprises metakaolin, fly ash, CA80 high-alumina cement, an exciting agent and an organic matter binder, the organic matter binder comprises redispersible latex powder and / or polyvinyl alcohol powder, and the organic matter binder comprises silica powder and / or silica powder. The heat insulation filler comprises expanded vermiculite, hydrophobic modified expanded perlite, sepiolite and hollow glass beads, the flame retardant comprises aluminum hydroxide and magnesium hydroxide, the fibers comprise glass fibers, and the auxiliaries comprise a foaming agent, a thickening agent, a foam stabilizer and an acrylic emulsion. The formed coating has the advantages of low carbon, low cost, excellent heat insulation performance and high-temperature strength, can be applied as a fire retardant coating of a fiber reinforced plastic (FRP), and can effectively protect an FRP reinforcing system.

The invention belongs to the field of coal solid waste resource utilization, and relates to a method for preparing a NaP type molecular sieve by utilizing kaolinite rock type coal gangue. The method comprises the following steps: 1) crushing and grinding blocky kaolinite rock type coal gangue into powder; 2) roasting and activating the coal gangue powder to obtain metakaolin; 3) mixing and stirring metakaolin, sodium hydroxide, a silicon source and deionized water to obtain an initial solution; 4) standing and aging the initial solution to obtain a precursor solution; 5) performing dynamic hydrothermal crystallization treatment on the precursor solution to obtain crystals; and 6) washing, neutralizing, centrifuging and drying the crystal to obtain the NaP type molecular sieve. The kaolinite rock type coal gangue is used as a raw material to replace a traditional chemical raw material required by molecular sieve synthesis, and resource utilization of aluminosilicate solid waste is promoted. According to the method, seed crystals or guiding agents are not required to be added in the molecular sieve crystallization process, and special crystallization methods such as microwaves and ultrasound are also not required, so that the process is simple, the cost is low, and the method is environment-friendly.

The invention relates to the technical field of cement-based anticorrosive materials, and particularly discloses a modified magnesium phosphate cement anticorrosive material as well as a use method and application thereof. The anticorrosive material comprises the following components in parts by weight: 100 parts of modified magnesium phosphate cement, 3-15 parts of a retarder, 1-10 parts of an epoxy resin glue solution, 0.5-5 parts of metakaolin and 15-20 parts of water. The modified magnesium phosphate cement comprises dead burned magnesium oxide and modified phosphate in a mass ratio of (1-4): 1. The modified phosphate is prepared from the following raw materials: nano aluminum oxide, sodium citrate and phosphate in a mass ratio of (0.5-1.5): (0.5-1.5): (20-25). The epoxy resin glue solution comprises uncured epoxy resin glue and a curing agent. The anti-corrosion material provided by the invention has the technical advantages of strong adhesive property and excellent anti-corrosion property, and can better provide protection for a steel structure serving in a marine environment.

The invention relates to the technical field of building materials, in particular to a wollastonite fiber-based high-temperature-resistant geopolymer and a preparation method thereof, and the high-temperature-resistant geopolymer is prepared from the following raw materials in parts by weight: 360 to 370 parts of metakaolin, 850 to 855 parts of fly ash, 470 to 475 parts of alkali activator, 160 to 165 parts of water and 121 to 183 parts of wollastonite fiber. By doping the wollastonite fiber, the pore structure of the geopolymer can be optimized, and the bridging effect of the fiber can effectively prevent microscopic cracks from developing to the macroscopic level, so that the mechanical property and high temperature resistance of the geopolymer are improved. The wollastonite fiber geopolymer disclosed by the invention has the advantages of good mechanical property, high temperature resistance and the like.

The invention discloses a rapid concrete repairing material based on microbial mineralization as well as a preparation method and application of the rapid concrete repairing material. According to the method, hydrophobic modified porous particles are used as a carrier, microbial bacteria, nutrient substances and a calcium source with mineralization behaviors are soaked into pores of the porous particles through vacuum impregnation, the pores of the particles are properly sealed by adopting waterborne epoxy, and then the particles are packaged by using metakaolin and sodium silicate, so that the porous particles are obtained. And finally, compounding with fiber composite mortar to prepare the concrete rapid repairing material. The rapid concrete repairing material has the advantages of strong interface adhesion, environment friendliness, light weight, excellent surface compactness improvement effect, crack self-repairing and the like, and can be used for coating and repairing the defect surface of concrete.

The invention belongs to the technical field of solid waste resource utilization, and discloses an activity-enhanced solid waste-based sludge curing agent as well as a preparation method and application thereof. The sludge curing agent comprises the following raw materials in percentage by mass: 30-40% of cement, 15-25% of S95 mineral powder, 15-23% of steel slag powder, 16-26% of an activity enhancing component and 0.5-3% of a composite exciting agent, wherein the activity enhancing component is prepared from the following raw materials in percentage by mass: 35 to 40 percent of desulfurized gypsum, 35 to 40 percent of carbide slag and 20 to 30 percent of biomass ash; the composite exciting agent comprises the following raw materials in percentage by mass: 30-35% of metakaolin, 30-35% of sodium sulfate, 15-20% of sodium silicate and 15-20% of sulfonated oil. According to the sludge curing agent, the industrial solid waste accounts for 57% or above, the desulfurized gypsum, the carbide slag and the biomass ash form an activity enhancing component, the activity enhancing component is matched with the composite exciting agent to jointly enhance and excite the activity of the metallurgical slag solid waste, and therefore the excellent curing effect is achieved, and when the sludge curing agent is used for sludge curing, the 3d unconfined compressive strength of a sludge curing body is larger than or equal to 0.5 MPa; and the 28d unconfined compressive strength is greater than or equal to 1.4 MPa.

The invention discloses a household garbage incineration fly ash based geopolymer and a preparation method thereof, and relates to the technical field of household garbage incineration fly ash. The household garbage incineration fly ash based geopolymer is prepared from the following raw materials in percentage by mass: 31.1 to 34.94 percent of fly ash, 2.2 to 7.51 percent of dolomite powder, 9.98 to 11.1 percent of metakaolin, 4 to 4.47 percent of sodium hydroxide, 24.9 to 28.09 percent of liquid water glass and 17.36 to 26.7 percent of deionized water. The prepared fly ash-based geopolymer has a good curing effect on chloride ions and can meet high-standard environmental protection requirements, the mixing amount of fly ash in the fly ash-based geopolymer reaches 31.1-34.94%, the preparation cost of the fly ash-based geopolymer is reduced, economic benefits are improved, and the fly ash-based geopolymer is suitable for large-scale production and application.

The invention relates to the technical field of building materials, and particularly discloses a slag and ardealite synergetic activated gypsum batten and a preparation method thereof.The slag and ardealite synergetic activated gypsum batten comprises pretreated ardealite, superfine slag powder, a composite exciting agent, reinforced fibers, self-repairing microcapsules, a foaming agent and water, and the composite exciting agent is formed by compounding nano SiO2, CaO and metakaolin; the preparation method comprises the following steps: mixing nano silica sol and a lignin solution, performing spray drying, and performing heat treatment to obtain the self-repairing microcapsule; the preparation method comprises the following steps: carrying out dry mixing on pretreated phosphogypsum, superfine slag powder and a composite exciting agent, adding water, adding reinforced fibers, self-repairing microcapsules and a foaming agent, stirring to form slurry, carrying out injection molding on the slurry, and carrying out stepped maintenance of pre-maintenance, main maintenance and carbonization treatment to prepare the modified red mud-pretreated phosphogypsum-based self-repairing self-repairing composite phosphogypsum-based self-repairing self-repairing composite phosphogypsum-based self-repairing composite phosphogypsum-based self-repairing composite phosphogypsum-based self-repairing composite phosphogypsum. The composite excitant synergistically activates the activity of the slag, and is matched with the reinforced fibers, the self-repairing microcapsules and stepped curing, so that solid waste resource utilization is realized, the compression resistance, bending resistance and impact resistance of the batten are improved, and the environment-friendly and high-performance effects are achieved.

The invention relates to the technical field of concrete waterproofing agents, in particular to a high-efficiency concrete anti-crack waterproofing agent and a preparation method thereof, and the high-efficiency concrete anti-crack waterproofing agent is prepared from the following raw materials in parts by weight: a calcium sulphoaluminate expanding agent; light burning of magnesium oxide; re-burning the magnesium oxide; nano-scale silicon dioxide; metakaolin; polypropylene fibers; basalt fibers; styrene-acrylic emulsion; a silane emulsion; silica fume; hydroxypropyl methyl cellulose; and a polycarboxylic acid water reducer compatilizer. According to the high-efficiency concrete anti-crack waterproof agent disclosed by the invention, the nano-silica, the metakaolin and the styrene-acrylic emulsion synergistically block nano-to-macroscopic multi-stage pores, so that double waterproofing of physical filling and chemical film forming is realized; the polypropylene and the basalt fiber are subjected to ultrasonic dispersion and interface combination optimization to form a three-dimensional anti-crack network, the component uniformity and the functional stability are ensured through precise proportioning, graded mixing and directional granulation, meanwhile, the waterproof agent is compatible with industrial production fluctuation, large-scale application reliability is ensured, and the problems that a traditional waterproof agent is single in function and insufficient in durability are solved.

The invention discloses a stable curing material of high-expansibility heavy metal polluted clay and a preparation method of the stable curing material, belongs to the technical field of engineering materials and environmental engineering, and is used for solving the technical problems that in the prior art, all curing components in the stable curing material are poor in binding property and poor in adsorbability to polluted heavy metal elements. The preparation method comprises the following steps: synthesizing an intermediate A from composite carbide slag pellets, a modified adhesive, an alkaline excitation material, dead burned magnesium oxide, metakaolin, polyvinyl alcohol, chlorocyclopropane and methyltrimethoxysilane, reacting allyl bromide with methyl trichlorosilane to obtain allyl chlorosilane, reacting the intermediate A with allyl chlorosilane to obtain the modified calcium carbide slag pellets. The modified adhesive with high viscosity and strong adsorbability is obtained, the fly ash, the modifier and the carbide slag are mixed, and high-strength and high-stability composite carbide slag pellets are obtained through spheroidizing treatment and high-temperature calcination, so that the prepared stable curing material has the advantages of being excellent in adsorption curing performance and good in overall stability.

The invention discloses multi-scale toughened full-solid-waste ultrahigh-ductility concrete, which is prepared from the following raw materials in parts by weight: 500 to 650 parts of full-solid-waste cementing materials, 110 to 150 parts of calcined coal gasification slag, 190 to 250 parts of calcined fly ash, 20 to 40 parts of silica fume, 10 to 30 parts of metakaolin, 780 to 930 parts of washed sand, 10 to 25 parts of fly ash fibers, 0.6 to 0.9 part of hydroxypropyl methyl cellulose, 20 to 30 parts of polycarboxylic acid water reducing agents and 300 to 400 parts of water. The calcined coal gasification slag is subjected to gradient heating to 800-960 DEG C, heat preservation is conducted for 30-60 min, then the calcined coal gasification slag is cooled to the room temperature at the cooling rate of 10-15 DEG C / min, and the calcined coal gasification slag is obtained after powder grinding. According to the multi-scale toughened full-solid-waste ultrahigh-ductility concrete provided by the invention, the toughness and the mechanical property of the concrete can be enhanced, the performance of the concrete in an extreme environment is improved, meanwhile, the solid waste utilization rate is increased, and the production cost of the concrete is reduced.

The invention relates to the technical field of mortar, in particular to cement self-leveling anti-crack and anti-seepage mortar and a preparation method thereof. The cement self-leveling anti-cracking and anti-seepage mortar is prepared from the following raw materials in parts by mass: 50 to 70 parts of Portland cement, 70 to 90 parts of quartz sand, 5 to 10 parts of nano metakaolin, 1 to 3 parts of calcium sulfate, 5 to 10 parts of polyethylene fiber, 1 to 2 parts of nonionic surfactant, 1 to 2 parts of silane coupling agent, 3 to 8 parts of composite basalt fiber, 0.5 to 1.5 parts of polycarboxylate superplasticizer and 1 to 3 parts of defoaming agent. 1-3 parts of hydroxypropyl methyl cellulose, 1-2 parts of a retarder and 0.5-1.5 parts of a coagulant. The mortar material has good anti-cracking performance and anti-seepage performance and excellent durability, can effectively solve the problem that the anti-cracking performance and the anti-seepage performance of the mortar material in the prior art cannot meet the environmental requirements, and is suitable for large-scale popularization and application.

The invention relates to the technical field of oil and gas well cementing cement paste, and discloses an anti-corrosion material for cement paste, carbon dioxide corrosion resistant cement paste and a preparation method and application of the carbon dioxide corrosion resistant cement paste. The anti-corrosion material comprises a mixture A and a mixture B, wherein the mixture A comprises activated carbon, nano silicon dioxide and nano aluminum oxide; the mixture B comprises a component C and a component D; the component C is selected from diatomite and / or fly ash; the component D is selected from one or more of metakaolin, pumice and coal gangue. The anti-carbon dioxide corrosion cement paste prepared from the anti-corrosion material has good anti-corrosion capability in a CO2 corrosion environment, the compressive strength of set cement before corrosion is higher, the structure is compact, the compressive strength of the set cement after corrosion is not obviously reduced, the permeability is small, the mechanical property is good, the sedimentation stability is good, the rheological property is good, and the like. And the well cementation quality of the CCUS well is guaranteed, and efficient storage of CO2 is achieved.

The invention discloses a coal gangue-based reinforced cement composite material and a preparation method thereof, and relates to the technical field of building materials. The coal gangue-based reinforced cement composite material is prepared from a coal gangue-based reinforced admixture, calcium ion doped modified multi-walled carbon nanotubes, polypropylene fibers, P.O42.5 Portland cement, metakaolin, silica fume, a polycarboxylate superplasticizer and water, calcium ion doped modified multi-walled carbon nanotubes and a coal gangue based reinforced admixture are cooperatively added into a cement matrix, seamless filling from nanometer to micrometer is achieved, a tough interface transition area is formed, pressure is jointly borne by a compact matrix and a strong interface, the compressive strength and breaking strength of the material are remarkably enhanced, and meanwhile, the compressive strength and breaking strength of the material are greatly improved. Migration of moisture and ions is effectively blocked, and the anti-permeability performance of the material is improved.

The invention relates to the technical field of concrete materials, and particularly discloses a composite mineral admixture, a preparation method thereof and concrete. The preparation method of the composite mineral admixture comprises the following steps: mixing and modifying dolomite powder, gypsum and calcium hydroxide to obtain pre-modified dolomite powder; then adding hexadecyl trimethyl ammonium chloride and octylphenol polyoxyethylene ether to obtain modified dolomite powder; and adding nickel slag, metakaolin, desulfurized fly ash and a grinding aid, and grinding to obtain the composite mineral admixture. The concrete prepared from the composite mineral admixture is excellent in compressive strength, shrinkage resistance, permeation resistance and the like, and the strength and durability of the concrete can be remarkably improved.

The invention discloses a low-carbon concrete material containing solid wastes and a preparation method of the low-carbon concrete material, and relates to the technical field of concrete materials. The concrete material is prepared from the following components in parts by weight: 520 to 660 parts of a cementing material, 1380 to 1650 parts of aggregate, 1.218 to 1.845 parts of an additive and 25 to 45 parts of other additives, specifically, the cementing material is prepared from 250 to 300 parts of cement, 120 to 150 parts of fly ash, 100 to 130 parts of slag powder, 20 to 30 parts of silica fume and 30 to 50 parts of metakaolin. A large amount of solid wastes are used in the formula, so that the pollution pressure on the environment is effectively reduced by utilizing the wastes; by reducing the use amount of the cement and replacing part of the cement with various solid wastes, the carbon emission in the concrete production process is effectively reduced, and the raw material cost is reduced.

The invention discloses steel fiber reinforced metakaolin-based recycled concrete and a preparation method thereof, and belongs to the technical field of civil engineering materials. The concrete is prepared from the following components in percentage by mass: 60wt%-80wt% of recycled aggregate, 20wt%-40wt% of a cementing material, 0.5 wt%-1.4 wt% of steel fibers and 0.1 wt%-0.7 wt% of an additive, wherein the cementing material comprises cement and metakaolin, and the mass ratio of the metakaolin to the cement is (1-3): (7-9). A nano silicon dioxide coating is arranged on the surface of the steel fiber. The preparation method adopts a step-by-step stirring process. The problem that dynamic impact resistance and green low carbon are difficult to cooperate in the prior art is solved, through component optimization and process control, the dynamic compressive strength of the concrete is improved, the energy absorption capacity is improved, the damage mode is converted into ductility from brittleness, fiber distribution is uniform, and the concrete is suitable for impact-resistant projects such as airport runways and protective structures.

The invention provides high chloride ion permeation resistance steel fiber fine aggregate concrete and a preparation method thereof. The high chloride ion permeation resistance steel fiber fine aggregate concrete comprises the following raw materials in parts by weight: 200-300 parts of cement; 30 to 50 parts of metakaolin; 100 to 200 parts of fly ash; 50 to 100 parts of mineral powder; 1-8 parts of nano silicon dioxide; 800 to 1000 parts of sand; 800 to 1000 parts of stone; 10 to 60 parts of steel fiber; 150 to 200 parts of water; and 5-20 parts of a water reducing agent. The steel fiber fine aggregate concrete with high chloride ion permeation resistance has the advantages of improved mechanical properties and durability, extremely high chloride ion permeation resistance, excellent volume stability, low material cost, economic feasibility of large-scale application, and wide application prospect. And the strict service requirements of the urban rail transit ballast bed under the long-term dynamic load, stray current and erosion medium coupling effect are precisely met.

The invention discloses an active mineral admixture for low-grade attapulgite-based sprayed concrete as well as a preparation method and application of the active mineral admixture. The active mineral admixture comprises the following components in parts by mass: 40-60 parts of active attapulgite, 10-20 parts of active rectorite, 5-20 parts of active montmorillonite, 5-15 parts of silica fume, 5-25 parts of metakaolin, 10-20 parts of fly ash and 0.5-6 parts of a water reducing agent. Minerals used in the invention are rich in reserves and low in price, and a stable raw material source is provided for the mineral admixture for the sprayed concrete. When the sprayed concrete obtained on the basis of the active admixture is used for construction operation, the block falling rate and the rebound rate are greatly reduced, the compressive strength is greatly improved, and good economic and environmental benefits and wide application prospects are achieved.

A superhydrophobic self-luminous concrete material for 3D printing and a method for preparing the same, belonging to the field of building materials. The superhydrophobic self-luminous concrete includes: cement: 1000-1500 parts; quartz sand: 1000-1300 parts; silica fume: 50-100 parts; water: 300-400 parts; water reducing agent: 8-12 parts; cellulose ether: 1-2 parts; defoamer: 2-3 parts; fiber: 4-8 parts; luminous powder: 75-85 parts; reflective powder: 30-45 parts; metakaolin: 15-25 parts; metal filler: 0.015-0.040 parts; and a superhydrophobic coating. By combining 3D printing with the superhydrophobic self-luminous concrete material, the characteristics of energy saving, environment friendliness, high efficiency and low consumption of the 3D printing are highlighted, and the superhydrophobic self-luminous concrete material can be utilized to efficiently prepare fine and special-shaped components.