12516results about "Solid waste management" patented technology

The invention relates to the technical field of concrete wall materials, and discloses a recycled concrete wall material and a preparation method thereof, the recycled concrete wall material comprises the following components by weight: 300-500 parts of recycled coarse aggregate, 200-400 parts of recycled fine aggregate, 150-300 parts of cement, 30-80 parts of fly ash, 3-8 parts of a water reducer, 5-15 parts of reinforced fiber, and 20-30 parts of a modified composition. Comprising the following steps: S1, raw material pretreatment, S2, mixing and stirring, S3, molding and curing, and S4, quality detection. The building waste is efficiently utilized, exploitation of natural aggregate is reduced, energy consumption and carbon emission in the production process are reduced, the landfill amount of the building waste and land occupation are reduced, the material strength and durability are good, the waterproof performance is improved, and the crack resistance and seismic resistance of the wall are enhanced.

The invention provides methods and compositions for treating wash water from concrete production with carbon dioxide. The treated wash water can be reused as mix water in fresh batches of concrete.

The invention discloses high-toughness ultra-high performance concrete and a preparation method thereof, and relates to the technical field of polymer modified materials thereof. The concrete is composed of a cementitious material composite system, a fiber-reinforced system and a polymer modifier, the cementitious material comprises Portland cement, nano-silica, a rice hull ash-based auxiliary cementitious material and gradient grading quartz powder, and the fiber system adopts steel fiber / basalt fiber / polypropylene fiber multi-scale composite reinforcement. And a polyurethane emulsion interface modifier is matched. During preparation, a dry mixing-fiber dispersion-wet mixing three-stage process is combined with a microfluidization emulsification and segmented polymerization technology, so that uniform dispersion of fibers and matrix-fiber interface reinforcement are realized. The scheme has high strength, high toughness and industrial feasibility, and is suitable for harsh engineering scenes such as bridge joints and explosion-proof structures.

The invention discloses solid-waste-based fluid-state solidified soil and a preparation method thereof, and belongs to the technical field of solid waste resource utilization. Raw soil is used as a base material, a curing agent composed of steel slag, granulated blast-furnace slag, gypsum, fly ash, aluminate and other industrial solid waste, a flocculating agent, a conditioning agent, a modifying agent, a stabilizing agent and a soil modifying agent are doped, and then the solid-waste-based fluid-state solidified soil is prepared. Adding water and stirring to form premixed flow-state solidified soil; comprising dry powder and water, and the mass ratio of the water to the dry powder is 0.65-0.75; the dry powder comprises the following components in parts by mass: 80-85 parts of raw soil, 10-15 parts of a curing agent, 2-5 parts of a flocculating agent, 0.5-1.5 parts of a conditioning agent, 1-3 parts of a modifying agent, 0.2-0.4 part of a stabilizing agent and 3-5 parts of a soil modifying agent. The solid-waste-based fluid-state solidified soil prepared by the method has the characteristics of high fluidity, high strength, relatively good water stability, low cost and the like, is beneficial to actual production, and conforms to a green development mode.

The invention provides a self-leveling rapid repair mortar based on a steel slag solid waste cementing material and a preparation method thereof, the self-leveling rapid repair mortar comprises the following components in parts by mass: 100 parts of a self-leveling rapid repair mortar cementing material: 20-32 parts of steel slag powder, 20-30 parts of slag powder, 10-23 parts of raw ash, 10-15 parts of desulfurized gypsum, 5-8 parts of silica fume, and 8-25 parts of rapid hardening sulphoaluminate cement; the fine aggregate comprises 50 parts of quartz sand and 50 parts of steel slag aggregate; 0.3 to 0.7 part of a polyether defoaming agent, 0.05 to 0.25 part of lithium carbonate and 6 to 12 parts of a polycarboxylic acid water reducing agent; and 25-28 parts of water. According to the self-leveling rapid repair mortar based on the steel slag solid waste cementing material, on the basis of an alkali excitation synergistic sulfate excitation mechanism, the solid waste materials such as the steel slag powder, the slag powder, the raw ash and the desulfurized gypsum are utilized, and through proportioning optimization, the self-leveling rapid repair mortar which can open traffic within 2 hours and has the compressive strength gt within 28 days is prepared; the bonding strength is gt; the self-leveling mortar for rapidly repairing the cement concrete pavement has the advantages of self-leveling, no shrinkage of later strength and excellent durability.

The invention relates to the technical field of concrete preparation, in particular to a mix proportion design method of fiber-compensating shrinkage self-healing concrete, which comprises the following steps: S1, determining a concrete formula and forming a final experiment matrix; s2, preparing first concrete samples according to the final experiment matrix, testing the multiple first concrete samples one by one, and collecting test parameters to form a database; establishing a concrete mix proportion prediction model according to the database; s3, inputting the actual environment temperature and humidity and the actual production parameters into the concrete mix proportion prediction model, and searching an optimal mix proportion by using an optimization algorithm; s4, verifying whether the optimal mix proportion meets a target or not; through systematized experimental design and data analysis, accurate customization of the concrete mix proportion is realized, the performance stability and adaptability of the fiber compensation shrinkage self-healing concrete are remarkably improved, and the research and development cost and time are effectively reduced.

The invention discloses fiber-reinforced anti-crack concrete and a preparation method thereof, and relates to the technical field of building materials, the fiber-reinforced anti-crack concrete comprises the following raw material components: 310-450 parts of cement, 150-190 parts of water, 930-1200 parts of coarse aggregate, 630-800 parts of fine aggregate, 80-180 parts of mineral active admixture, 1.2-18 parts of multi-element composite fiber, 1.8-4.5 parts of polycarboxylic acid water reducer, and 20-35 parts of anti-crack synergistic system. Through a quaternary fiber system, a three-dimensional interlocking net-shaped crack-resistant framework is formed in concrete slurry, the problems that the single fiber reinforcement effect is limited, and the interface bonding force with a concrete matrix is insufficient are solved, and the crack resistance and the mechanical property of the concrete are improved.

A fireproof magnesium oxide board is prepared by mixing the following raw materials, the raw material names and weight parts are as follows: 80-100 parts of magnesium oxide; 20-30 parts of anhydrous magnesium chloride; 10-20 parts of modified expanded vermiculite foaming agent; 20-30 parts of aluminum silicate fiber; 5-10 parts of sawdust; 10-15 parts of fly ash; 8-12 parts of glass magnesium board crushed powder; 1.5-5 parts of non-woven fabric; 10-20 parts of water; wherein the modified expanded vermiculite is prepared by the following steps: (1) Vermiculite is incompletely expanded and calcined; (2) acrylic acid monomer, sodium hydroxide, acrylamide monomer, initiator potassium persulfate, crosslinking aid pentaerythritol polyglycidyl ether, incompletely expanded vermiculite, and water are taken, stirred evenly and ultrasonically dispersed to obtain a first reaction solution, which is placed in a reactor for reaction to obtain a gel material; (3) the gel material is preliminarily crushed and dried, and then further crushed in a ball mill to obtain a fire-resistant expanded vermiculite with water absorption performance.

The invention relates to the field of self-repairing concrete, in particular to high-strength self-repairing concrete and a preparation method thereof. The high-strength self-repairing concrete comprises the following substances in parts by weight: 45-60 parts of cement; 100 to 120 parts of recycled coarse aggregate; 65 to 80 parts of fine aggregate; 10 to 20 parts of water; 0.1 to 0.3 part of a water reducing agent; the recycled coarse aggregate is the recycled coarse aggregate immobilized with self-repairing microorganisms, and the self-repairing microorganisms comprise at least one of bacillus subtilis, bacillus megatherium and bacillus pasteurii. The concrete crack self-repairing capability is endowed through the immobilized self-repairing microorganisms. The microorganisms form resting spores in the concrete, when cracks are generated and water permeates into the cracks, the microorganisms are activated and metabolize a calcium source and urea in the surrounding environment, calcium carbonate crystals are generated through the mechanism that the microorganisms induce carbonate precipitation, the cracks are filled, and the structural integrity is recovered. The process does not need external intervention, and the mechanical structure and mechanical properties of the concrete structure can be remarkably improved.

The invention provides anti-cracking and anti-seepage high-performance concrete, which relates to the technical field of concrete and comprises Portland cement, aggregate, a high-activity mineral admixture, a calcium-magnesium composite expanding agent, nano silicon dioxide particles, a microcapsule-packaged sodium silicate and calcium lactate solution, paraffin / expanded graphite composite phase change microspheres, steel fibers, PVA fibers and nano cellulose. The self-repairing concrete has the characteristics that the anti-cracking performance is comprehensively improved, the anti-seepage grade is broken through, the self-repairing capability is long-acting, the construction adaptability is enhanced, and the like.

The invention relates to the field of solidified soil, and particularly discloses solid-waste-based premixed flow-state solidified soil and a preparation method thereof. The solid-waste-based premixed flow-state solidified soil comprises soil, water and a curing agent according to the weight ratio of (28-36): (50-54): (6-9), according to the total weight of the curing agent, the curing agent comprises the following components in parts by weight: 20-40 parts of fly ash, 30-47 parts of slag, 6-18 parts of silica fume, 10-15 parts of sea sludge, 1-3 parts of a water reducing agent, 1-3 parts of sodium hydroxide, 1-3 parts of calcium sulphoaluminate, 3-10 parts of a fiber reinforced material and 1-3 parts of phosphate. The problems that stress generated by the solidified soil in the hydration process is excessively concentrated and shrinkage is excessive can be solved, and therefore cracking of the solidified soil subjected to premixed flow state solidification is reduced.

The invention discloses a yellow phosphorus tailing-based mine filling material and application thereof. The yellow phosphorus tailing-based mine filling material comprises aggregate and a cementing material, the cementing material comprises the following components in parts by mass: 5-20 parts of red mud, 20-40 parts of yellow phosphorus slag, 10-30 parts of slag, 5-10 parts of fly ash, 5-10 parts of a compound exciting agent, 1-3 parts of an early strength agent and 2-5 parts of a water-retaining agent; wherein the compound exciting agent comprises the following components in parts by mass: 10-20 parts of sodium metasilicate, 30-40 parts of gypsum powder, 20-30 parts of sodium sulfate, 5-10 parts of carbide slag and 5-10 parts of silica fume; according to the invention, the raw materials are compounded and the specific exciting agent is subjected to depolymerization-polycondensation reaction to obtain a cementing material containing Aft (ettringite), C-S-H gel (hydrated calcium silicate gel) and C-A-S-H gel (hydrated calcium aluminosilicate gel), and finally, the mine filling material with high fluidity, low bleeding rate and high strength is obtained while yellow phosphorus tailing solid waste is treated.

The invention discloses efficient sound-absorbing lightweight aggregate foam concrete as well as a preparation method and application thereof, and belongs to the field of inorganic non-metallic materials. The high-efficiency sound-absorbing lightweight aggregate foam concrete is prepared from the following components in parts by weight: 85 to 95 parts of a sulfur-aluminum-iron series low-carbon cementing material, 5 to 15 parts of an auxiliary cementing material, 0.6 to 1.5 parts of a functional additive, 20 to 60 parts of unfired lightweight aggregate, 0.35 to 0.45 part of water and 0.5 to 1.5 L of prefabricated foam, the baking-free lightweight aggregate comprises the following components in parts by weight: 40-50 parts of a sulfur-aluminum-iron series low-carbon cementing material, 50-60 parts of byproduct gypsum, 0.7-1.5 parts of a chemical foaming agent, 15-22 parts of water and 5-8 parts of expanded perlite. According to the invention, a multi-stage-multi-scale pore structure body with expanded perlite pores, hydrogen peroxide foaming pores and physical foaming pores is constructed, so that the balanced broadband sound absorption performance of the material is realized, the sound absorption frequency range is adjustable, the sound absorption and noise reduction coefficient (NRC) of the material is greater than or equal to 0.80, the volume weight is less than or equal to 500 kg / m < 3 >, and the breaking strength is greater than or equal to 1.5 MPa.

The invention provides an ardealite road base material and a preparation method thereof, and belongs to the field of road base materials. The road base material is prepared from the following raw materials in parts by weight: 850 to 900 parts of phosphogypsum, 5 to 15 parts of quick lime, 40 to 60 parts of cement, 55 to 85 parts of composite curing agent and 8.5 to 13 parts of curing exciting agent. The phosphogypsum is modified, so that soluble phosphorus and soluble fluorine in the phosphogypsum are cured; the curing exciting agent is atomized and added into the mixture of the modified phosphogypsum, the cement and the composite curing agent, so that all the components are in full contact, the hydration effect is promoted, and the strength and stability of the base material are improved. The pavement base material provided by the invention consumes a large amount of phosphogypsum, can effectively relieve the problem of accumulation of a large amount of phosphogypsum, reduces environmental pollution, has good mechanical properties, water stability and durability, is applied to highway construction, and has important environmental protection significance and social benefits.

The invention discloses low-carbon high-freezing-resistance magnesium phosphate cement mortar and a preparation method and application thereof, and belongs to the technical field of constructional engineering materials, the mortar comprises low-carbon magnesium phosphate cement, river sand, hydrolyzed silanol and mixing water; the hydrolyzed silanol is a product obtained by hydrolyzing a silane coupling agent in ethanol and water under an acidic condition; the invention relates to a high-strength concrete, which is prepared from the following formula components in parts by mass: 145 to 250 parts of low-carbon magnesium phosphate cement, 145 to 250 parts of river sand, 7 to 35 parts of silane coupling agent, 42 to 210 parts of ethanol, 21 to 105 parts of water and 10 to 30 parts of water for mixing. The cement has the advantages of adjustable setting time, low carbon, energy conservation, good mechanical properties, strong water resistance and freezing resistance and the like.

The invention discloses sound-insulation and heat-insulation building mortar and a preparation method thereof, and relates to the technical field of building materials, the sound-insulation and heat-insulation building mortar comprises, by weight, 42-48 parts of a cementing material, 15-25 parts of an auxiliary material, 17-22 parts of lightweight aggregate, 30-35 parts of a functional filler, and 1-2 parts of an additive; the cementing material is a mixture of sulphoaluminate cement and Portland cement; the auxiliary material is a mixture of fly ash and quartz sand, the lightweight aggregate is a mixture of 20-40-mesh hollow vitrified microbeads and 70-90-mesh hollow vitrified microbeads, and the mass ratio of the hollow vitrified microbeads to the hollow vitrified microbeads is 1: (2-3); the functional filler is a mixture of modified waste rubber particles and modified fibers; the additive is a mixture of a polycarboxylate superplasticizer and hydroxypropyl methyl cellulose ether. The mortar disclosed by the invention is good in thermal insulation performance and excellent in mechanical property, the method disclosed by the invention is simple to operate and low in cost, and the prepared mortar is excellent in performance.

The invention discloses ultra-high performance concrete and a preparation method thereof. The ultra-high performance concrete comprises the following components in percentage by mass: 15%-25% of cement, 3%-6% of nano SiO2, 30%-35% of fly ash or steel slag powder, 35%-40% of recycled aggregate, 1%-4% of fiber, 0.5% of a microbial remediation agent and 1%-3% of nano TiO2. The preparation method comprises the following steps: S1, pretreating the recycled aggregate; and S2, packaging the microbial remediation agent: mixing the bacillus pasteurii spores with calcium lactate, and wrapping the mixture in calcium phosphate microspheres. S3, step-by-step stirring; S3.1, dry mixing: uniformly stirring the cement, the fly ash, the nano SiO2, the nano TiO2 and the recycled aggregate; s3.2, wet mixing is carried out, water solution fibers containing the polycarboxylic acid water reducing agent are added, uniform stirring is carried out, and the water-binder ratio of the water solution containing the polycarboxylic acid water reducing agent is 0.18; s3.3, final mixing: adding the packaged microbial remediation agent, and uniformly stirring; and S4, directional curing: performing steam curing at 80 DEG C for 48 hours, performing ultraviolet irradiation, and performing constant-temperature and constant-humidity curing for 7 days. The ultra-high performance concrete has the effects of low cost, low carbon emission, multi-function integration and repeatable crack self-repairing.

The invention provides a building solid waste recycled aggregate preparation system with multi-layer screening and intelligent judgment functions and an operation method. The construction method comprises the construction steps of waste transportation and throwing, manual sorting, waste crushing, cleaning and impurity removal, fine crushing, multi-stage screening, quality detection and control, finished product storage and transportation and recycled aggregate application. According to the building solid waste recycled aggregate preparation system with the multi-layer screening and intelligent judgment functions and the operation method, accurate regulation and control of the screening process are achieved, and the production efficiency is remarkably improved. The quality stability of the recycled aggregate is ensured, the influence of building wastes on the environment is reduced, and the cyclic utilization of resources is promoted. By adopting the technology, the production scheme can be quickly adjusted according to market requirements, the adaptability is high, and more economic benefits are created for enterprises.

The invention discloses a method for harmlessly treating lithium slag and preparing a water-stable material from the treated lithium slag. The method comprises the following steps: crushing the lithium slag; mixing a sulfuric acid-containing material with the crushed lithium slag to obtain a pulpified mixture; roasting, and carrying out chemical modification to obtain roasted slag; adding a material containing activated aluminum oxide into the roasting slag to obtain a mixed material; the mixed material is subjected to water leaching and filtering, and leaching residues and leaching liquid are obtained; and drying the leaching slag, adding an exciting agent, and grinding to finally obtain the detoxified lithium slag. And preparing the water-stable material from the detoxified lithium slag. Under the condition of effectively improving the quality of the cement-stabilized layer, the lithium slag resource is effectively utilized, the resource utilization rate is improved, and the mechanical strength and corrosion resistance of the cement-stabilized layer concrete can be effectively improved by matching with the exciting agent and the curing agent.

The invention relates to the technical field of building materials, in particular to a Yellow River superfine sand aggregate interface reinforcing agent and a preparation and use method thereof.The interface reinforcing agent is prepared from 0.05-0.1 part of graphene oxide powder, 50-100 parts of a silane coupling agent, 50-100 parts of nano-silicon dioxide, 10-30 parts of oxalic acid and 5000-7000 parts of water; graphene oxide powder, a silane coupling agent and nano silicon dioxide are jointly used for preparing an interface modifier for performing interface modification treatment on the Yellow River superfine sand, so that the interface bonding force between the Yellow River superfine sand and a cement hydration product is enhanced.

The invention relates to a flame-retardant inorganic quick-setting material and a preparation method thereof, and the flame-retardant inorganic quick-setting material is prepared from the following raw materials: sulphoaluminate cement, aluminum-magnesium hydrotalcite, phosphorus slag powder, waste PBO fiber, an accelerator, a water reducer, a functional auxiliary agent, and 3, 3 '-diamino-4, 4'-difluorodiphenyl sulfone. The functional auxiliary agent comprises structural units introduced by the following monomers: 3-[N, N-dimethyl-[2-(2-methylpropyl-2-enoyloxy) ethyl] ammonium] propane-1-sulfonic acid inner salt, diphenyl (4-vinyl phenyl) phosphine oxide, 1, 3-bis (oxirane methyl)-5-(2-allyl)-1, 3, 5-triazine-2, 4, 6 (1H, 3H, 5H)-triketone, 10-(4-vinyl phenyl)-10H-phenoxazine and itaconic acid. The material is high in strength, remarkable in rapid hardening and flame-retardant effect, and safe and environment-friendly to use.

The invention relates to the technical field of concrete preparation, in particular to high-performance self-compacting concrete and a preparation method thereof, solves the defects in the prior art, and comprises the following components: cement, fly ash, slag powder, graphene oxide, nano-silica aerogel, a water reducer and an air entraining agent. Through silanization modification and magnetic field induction, the problem of interface incompatibility of GO and SA is solved. Graded mass transfer paths are formed between nano layers of GO and mesopores and macropores of SA. And the CaCO3 seed crystal in the SA hole directionally guides the oriented growth of the C-S-H gel, so that the early strength development rate is increased.

The invention discloses a foam cement-based sound absorption material with an adjustable and controllable pore structure and a preparation method of the foam cement-based sound absorption material, and belongs to the technical field of building functional materials. Aiming at the problems of insufficient pore structure regulation and control, limited sound absorption performance and high cost of a traditional cement-based sound absorption material, P.O42.5R Portland cement is used as a basis, a physical-chemical synergistic foaming method and a three-stage gradient temperature control freeze-drying process are combined through the synergistic effect of a composite foaming agent, a microporous structure regulator and a composite pore forming agent, and the sound absorption material is prepared. Precise regulation and control of pores from the nm level to the mm level are achieved, and an interconnected pore channel network with the high open porosity is formed. The density of the obtained material is 200-1000 kg / m, the porosity is 60-90%, the aperture coverage range is 2 nm-6 mm, the open porosity is 70-85%, the 28d compressive strength is 1.83-14.56 MPa, the average sound absorption coefficient in the frequency range of 250-2000 Hz is 0.12-0.62, and the noise reduction coefficient is 0.14-0.64. The composite material has the characteristics of adjustable pore structure, light weight, high strength, broadband sound absorption, low cost and good durability, and is suitable for the noise control fields of building walls, traffic facilities and the like.

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.

The invention relates to the technical field of building materials, and particularly discloses a high-performance solid-waste-based grouting material and a preparation method thereof. Comprising the following raw materials in parts by weight: 32 to 54 parts of Portland cement, 12 to 16 parts of a modified admixture, 2.4 to 3.6 parts of a functional filler, 42 to 56 parts of aggregate, 45 to 55 parts of a photoinitiator solution, 0.6 to 0.8 part of a water reducing agent, 0.9 to 1.1 parts of a composite expanding agent, 0.04 to 0.06 part of a defoaming agent and 9.2 to 12.4 parts of deionized water. Siloxane groups, acylamino groups, ester groups and benzene rings are chemically bonded on the surface of the modified admixture, so that the hydrophilicity of the modified admixture is reduced, the modified admixture can form hydrogen-bond interaction with hydroxyl groups and cement hydrates on the functional filler, and meanwhile, a flexible long-chain alkane structure on the functional filler can be entangled with the modified admixture, so that the flexibility of the modified admixture is improved. The mechanical property, the durability and the fluidity of the grouting material are improved.

The invention belongs to the technical field of road construction, and particularly relates to a copper-doped tailing pavement base material as well as a proportion confirmation method and application thereof. The preparation method comprises the following steps: S1, preparing raw materials; s2, a compaction test method is adopted, and the void ratio of the compacted aggregate wrapped with the cement mortar is calculated; s3, according to the volume filling principle, the gravels form a basic framework, the void ratio of the gravels in the compaction state is measured, cement adhesive cement adheres to aggregate, the aggregate is filled in gaps of the framework formed by the gravels, and finally the blending proportion of the copper tailings, the gravels and the aggregate is determined by combining the composition mechanism and volume parameters of the mixture; and S4, calculating the using amount of the steel slag composite cementing material mucilage according to the thickness of the steel slag composite cementing material mucilage wrapping film and the specific surface area of the copper tailings. A skeleton filling theoretical method is adopted, the shrinkage effect of the filler in the skeleton is controlled, the cracking risk is reduced, and meanwhile the high strength is achieved.

The invention discloses an inorganic two-component grouting material for a mine and a preparation method and application thereof, and belongs to the technical field of inorganic grouting materials. The weight ratio of the component A to the component B is (0.3-1.2): 1, and the component A comprises superfine Portland cement, silicon powder, an expanding agent, a water reducing agent, a retarder, lithium carbonate, cellulose ether, a defoaming agent and latex powder; the component B comprises sulphoaluminate cement, slag, an expanding agent, a water reducing agent, lithium carbonate, cellulose ether, a defoaming agent, latex powder and a retarder; the weight ratio of the slag to the sulphoaluminate cement is (3.5-5.6): 1, and the weight ratio of the superfine Portland cement to the sulphoaluminate cement is (2.5-4): 1. The inorganic double-component grouting material for the mine can be rapidly solidified and has the functions of water plugging and reinforcement.

The present invention discloses a crack-resistant ultra-high performance concrete (UHPC) for underground engineering in water-rich strata, preparation method, and application thereof, belonging to the technical field of building materials. The concrete is prepared from the following raw materials in parts by weight: 550-650 parts of cement, 140-180 parts of fly ash, 120-150 parts of silica fume, 200-300 parts of calcined shield tunnel slag, 30-50 parts of micron-scale magnesium oxide, 30-50 parts of nano-scale magnesium oxide, 30-50 parts of rheology-modifying material, 800-1000 parts of lightweight aggregate, 4-8 parts of water reducer, and 50-200 parts of water. The rheology-modifying material has a fluidity ratio of 106%. The present invention incorporates calcined shield tunnel slag, micron / nano-scale magnesium oxide, and lightweight aggregate into the UHPC, which effectively suppresses shrinkage and reduces crack formation.

A U-shaped recycled concrete composite beam, and a design and construction method therefor, the U-shaped recycled concrete composite beam comprising a prefabricated concrete casing (11) and cast-in-place compression-zone concrete (12), wherein the prefabricated concrete casing (11) is a recycled concrete casing, and has a U-shaped appearance; the cast-in-place compression-zone concrete (12) is high strength concrete, and the cast-in-place compression-zone concrete (12) is concrete with a strength grade of C50-C80; the thickness h1 of the bottom of the prefabricated concrete casing (11) is not less than 80 mm, and the widths b1 and b3 of lateral surfaces of the prefabricated concrete casing (11) are both not less than 45 mm; the width b2 of the cast-in-place compression-zone concrete (12) is not less than 100 mm; and a steel bar cage is provided in the U-shaped recycled concrete composite beam to serve as a framework. Compared with the prior art, the fire-resistant characteristic of recycled concrete and the excellent mechanical properties of high-strength concrete are fully exerted, the flexural bearing capacity and ductility of the recycled concrete beam can be effectively improved at room temperature, the bursting phenomenon of a fire-exposed surface is reduced at a high temperature, and the temperature field in the beam is significantly reduced.

The coarse aggregate ultra-high performance concrete premix lifting, transferring and mixing device comprises a control system, an aggregate batching system, an aggregate lifting system, a dry mixing main machine system, a feeding vehicle, a steel fiber feeding system and a stirring system, the whole stirring process is automatically controlled and comprises key steps of automatic metering, automatic raw material feeding, mixing and the like, so that manual operation is remarkably reduced, errors and inconsistency caused by manual metering are avoided, and the accuracy and repeatability of stirring each time are ensured; step-by-step feeding of each part is coordinated through a control system, so that the stirring efficiency and the uniformity of concrete are improved; by establishing a relational expression between a concrete mixture stirring uniformity index and parameters such as the stirring time, the stirring speed, the number of stirring blades, the vibration frequency of the two-stage vibrating screen and the like, key parameters in the stirring process are more accurately controlled, and it is ensured that the stirring uniformity of each batch of concrete reaches a preset standard.