2610 results about "Crack resistance" patented technology

The invention relates to the technical field of anti-cracking performance testing, in particular to an ultra-high performance concrete anti-cracking performance testing system and a dynamic monitoring method thereof.The system comprises a dynamic stress field simulation feedback module used for sensing three-dimensional distribution of a micro stress field in concrete in real time by constructing a flexible loading array to obtain dynamic stress field data; the multi-scale damage evolution tracking module is used for deploying a high-resolution acoustic emission network and a distributed optical fiber sensing layer based on dynamic stress field data of the flexible loading array to form a full-scale evolution graph from microdefects to macroscopic cracks; and the intelligent healing efficiency evaluation module obtains stress redistribution data and a full-scale evolution graph, and a repairing medium containing a tracer agent is injected into a preset crack path. According to the method, the whole process of crack resistance of the material from defect initiation to repair and regeneration can be quantitatively evaluated; and finally, outputting a dynamic evolution rule of the crack resistance and enhancing potential evaluation.

The invention relates to the field of concrete, and provides high-strength concrete and a preparation method thereof, and the high-strength concrete comprises modified basalt chopped fiber, a self-repairing agent, cement, fly ash, slag powder, coarse aggregate, natural sand, a water reducing agent and an air entraining agent. The modified basalt chopped fiber is oxidized by hydrogen peroxide, etched by hydrochloric acid and modified by a nano silicon dioxide coating, so that the interface bonding force is enhanced. The self-repairing agent is prepared by adopting expanded perlite to load bacillus through thallus culture, purification, dipping adsorption and low-temperature vacuum drying, CaCO3 deposition can be induced at concrete cracks, and self-repairing is achieved. The invention further provides a preparation method of the concrete. The preparation method comprises the steps of aggregate screening, hydrated liquid preparation, wet mixing, fiber and self-repairing agent adding, vibration forming and curing. The crack resistance of the concrete is improved by enhancing the fiber-matrix interface bonding force, meanwhile, the service life of the concrete is prolonged by utilizing a biological self-repairing technology, and the concrete is suitable for high-durability concrete engineering.

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.

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 discloses an anti-cracking reverse design method for early-age concrete. Comprising the following steps: acquiring material performance parameters; constructing a chemical-thermal-force-phase field damage model of the early-age concrete; constructing a constitutive relationship between early-age behaviors and stress-strain of the concrete; carrying out shrinkage cracking simulation calculation on the early-age concrete, and quantitatively evaluating the damage cracking risk of the early-age concrete by using a damage development index Idd. And performing crack resistance optimization design on the early-age performance of the concrete by using an orthogonal design method to obtain a crack resistance optimization result in the performance combination and development process of the concrete. According to the method, the damage development index peak value is taken as a control target, the shrinkage cracking risk of the early-age concrete structure under different material properties, development processes, constraints and curing temperatures can be quantitatively evaluated, the optimal design of the concrete mix proportion is guided, a large amount of test exploration is avoided, the manpower and material resource cost is reduced, and the method is suitable for large-scale popularization and application. The method has important significance on early crack control of a concrete structure and has remarkable progress.

The invention provides a thermal protection coating as well as a preparation method and application thereof. The thermal protection coating comprises a NiCoCrAlY first bonding layer, a NiCoCrAlY second bonding layer, a CeYSZ first ceramic layer and a GdYbYSZ second ceramic layer which are sequentially arranged on the surface of a base material, and the second NiCoCrAlY bonding layer is made of CeO2 (CeO2) and Al2O3 (Al2O3). According to the invention, a thermal protection coating structure with double bonding layers and double ceramic layers is constructed on the surface of the base material, and CeO2 and Al2O3 nano-particle reinforced phases are introduced, so that the use temperature of the thermal protection coating is increased, and the thermal strain tolerance, the crack resistance and the oxidation resistance are greatly improved.

The invention provides a tear-resistant, wear-resistant, low-smoke and non-dripping sheath material as well as a preparation method and application thereof. The tear-resistant wear-resistant low-smoke non-dripping sheath material is prepared from the following components in parts by weight: 25 to 35 parts of metallocene linear low-density polyethylene, 10 to 15 parts of ethylene-vinyl acetate copolymer, 6 to 8 parts of compatilizer, 50 to 60 parts of aluminum hydroxide, 10 to 15 parts of magnesium hydroxide, 3 to 4 parts of microencapsulated red phosphorus, 5 to 8 parts of lithium oxide synergist, 4 to 6 parts of silicone master batch, 0.3 to 0.7 part of carbon black master batch and 1.5 to 2.5 parts of coupling agent. The tear-resistant wear-resistant low-smoke non-dripping sheath material provided by the invention has the characteristics of being halogen-free, flame-retardant, tear-resistant and wear-resistant, and a low-smoke halogen-free flame-retardant power cable prepared from the sheath material has the characteristics of high smoke light transmittance during combustion, no dripping and cracking resistance.

The invention discloses a mass concrete composite anti-crack structure and a crack control construction method based on the mass concrete composite anti-crack structure. The composite anti-crack structure comprises a core common concrete layer, an outer side anti-crack concrete layer, a reinforcing mesh arranged between the core common concrete layer and the outer side anti-crack concrete layer, and a top anti-crack concrete layer. The method comprises the steps that firstly, the thickness of side face anti-crack concrete and the thickness of top face anti-crack concrete needing to be poured are calculated according to cracking risk assessment, the side face anti-crack concrete is poured firstly, then core common concrete is poured, and it is ensured that the pouring height of the side face concrete is always 20-30 cm higher than the core common concrete; and then the top surface is completely constructed by adopting anti-crack concrete. The reinforcing mesh subjected to special treatment is adopted, so that the overall stress of the composite structure is uniform, the overall anti-cracking performance and durability of the composite structure are improved through the outer side anti-cracking concrete, the construction technology is simple, meanwhile, a large amount of construction cost and operation and maintenance cost can be saved, and the composite structure is suitable for application and popularization.

The invention provides a modified lithium sulfide solid electrolyte, a sulfide solid electrolyte, a preparation method thereof and a battery, and relates to the technical field of solid electrolyte materials. The preparation method of the sulfide solid electrolyte is different from a traditional doping technology, the high-stability sulfide solid electrolyte is prepared mainly through modification of lithium sulfide, the comprehensive performance of the sulfide solid electrolyte is improved, the ionic conductivity and chemical stability of the sulfide solid electrolyte are improved, and the service life of the sulfide solid electrolyte is prolonged. And the mechanical strength and the crack resistance are also obviously enhanced. The preparation method disclosed by the invention is simple, does not need to be carried out at high temperature, and does not need to use expensive raw materials and complex processes, so that the production cost is reduced, the application range of the sulfide solid electrolyte is expanded, and large-scale production and application of the sulfide solid electrolyte are favorably realized.

The invention relates to a preparation method of a geopolymer composite material based on modified fiber, which comprises the following steps: S1, fiber pretreatment: the fiber is one of basalt fiber and polyformaldehyde fiber; s2, performing surface roughening treatment on the fibers through a polyvinyl alcohol modified impregnating compound to obtain roughened fibers; s3, the roughened fibers are subjected to surface functional modification treatment through a functional modified impregnating compound, and functional modified fibers are prepared; s4, uniformly mixing the powder and an expanding agent according to a mass ratio, and adding an alkali activator solution and the functional modified fibers to prepare a geopolymer gel material; s5, the geopolymer gel material is subjected to stirring, mold filling, steam curing forming, demolding and continuous curing, and the geopolymer composite material based on the modified fiber is obtained.According to the preparation method, the geopolymer composite material with high strength and excellent crack resistance and toughness is obtained through alkali excitation, and the problems that geopolymers are low in toughness and large in brittleness are effectively solved.

The invention provides an aerogel-based heat-preservation, heat-insulation and waterproof composite coating material for a building outer wall and a preparation method thereof, and belongs to the field of building materials. Through hydrophobic modified silicon dioxide aerogel, a lightweight heat insulation frame is provided, and the waterproofness and compatibility are improved; the mechanical property and the crack resistance are enhanced through the modified potassium titanate nanofibers, and self-adaptive heat insulation is achieved; the thermoelectric effect, the wear resistance and the thermal regulation performance are optimized through plasma treatment and polyaniline coated tungsten carbide nanoparticles; the heat management performance, the crack resistance and the comprehensive heat insulation and waterproof capacity are improved through graphene oxide composite modified boron nitride; the flexibility, the hydrophobicity and the interfacial compatibility are improved through organic silicon modified bisphenol A epoxy resin; and the performance of the coating is optimized through the synergistic effect of the components.

The invention relates to a high-performance polymer-cement-based composite repair material and a preparation method thereof, and the high-performance polymer-cement-based composite repair material comprises the following components by mass: 690-710 parts of cement; 130 to 150 parts of fly ash; 45 to 55 parts of silica fume; 200 to 210 parts of mixing water; 950 to 1050 parts of fine aggregate; 21-23 parts of a modified polymer; 9-10 parts of an expanding agent; 4-5 parts of a water reducing agent; 5-6 parts of modified fiber; and 0.16 to 0.18 part of a defoaming agent. The nano-toughened modified polymer and the modified fiber are used, the nano-modified polymer can improve the microstructure of the repair material, the modified fiber can limit shrinkage of the repair material and enhance the crack resistance of a matrix, the toughness and the mechanical property of the repair material can be effectively improved through the synergistic effect of the nano-modified polymer and the modified fiber, and it is guaranteed that the repair material does not crack in the early stage.

The invention provides steam-cured alkali-activated fly ash concrete and a preparation method thereof. The steam-cured alkali-activated fly ash concrete is prepared from the following components in parts by mass: 30 to 40 parts of fly ash, 10 to 15 parts of slag, 10 to 20 parts of water glass, 60 to 80 parts of fine aggregate, 110 to 140 parts of coarse aggregate, 2 to 6 parts of water, 1 to 3 parts of nano SiO2 and 0.1 to 0.5 part of basalt fiber. The content of alkali in the water glass is 8.5-9.5%, and the modulus of the water glass is adjusted to 1.3-1.5 by using sodium hydroxide; the mass ratio of short fibers with the length of 6-12mm to long fibers with the length of 12-24mm in the basalt fibers is (0.5-2): 1. The alkali content, the water glass modulus and steam curing parameters are optimized, and meanwhile, nano SiO2 and basalt fibers are added for synergistic enhancement, so that the concrete has good crack resistance and compressive strength.

The present invention proposes an intermediate diaphragm-free, suspended formwork-free, and negative moment tooth block-free beam bridge, and a design method thereof. The beam bridge includes prefabricated main girders, a wet joint, lower structures, and pier cap transverse beams above the lower structures. The concrete deck slabs of adjacent prefabricated main girders are connected by the wet joint. The design method of the above beam bridge includes the following steps: S1, initial design of the main girders; S2, calculation of the non-uniform deflection of the main girders and the indirect transverse stress of the deck slabs; S3, calculation of the direct transverse stress of the deck slabs; S4, crack resistance verification of the deck slab; S5, optimization of bridge parameters to reduce the stress on the driving surface; S6, completion of the beam bridge design. The beam bridge and its design method effectively solve the problem that the existing intermediate diaphragm-free beam bridge is prone to longitudinal cracking at the joints, and realize the suspension tension without the wet joint suspended formwork of the deck slab and the negative bending moment tendon, and have better mechanical properties and better economic, environmental and social benefits, which can facilitate the promotion and application of such bridges in various types of highways , railways and municipal engineering.

The invention provides a laser welding method for tailor-welding hot forming steel with the tensile strength exceeding 1500 Mpa after hot forming before hot forming, and particularly relates to a method capable of avoiding cracking of a heat affected zone after welding. The hardness distribution of a heat affected zone is controlled during laser welding cooling, so that the hardness of the heat affected zone after welding does not exceed the highest hardness of a weld joint melting zone, and the highest hardness value does not exceed H / 3-20 HV; (H is the tensile strength of the material obtained after thermal forming); the minimum width of the heat affected zone is not less than 0.2 m; the method specifically comprises the steps that energy distribution of a laser welding heat source is controlled in the welding process, a laser beam forms a flat-top light source on the surface of a workpiece, a welding pool is formed when the light source irradiates the workpiece for welding, the welding pool has the length L and the width B, and L / B is larger than or equal to 3. A welded joint obtained through the laser welding method has excellent post-welding cracking resistance for welding of high-strength steel with the tensile strength exceeding 1500 Mpa after thermal forming.

The invention relates to the field of building material preparation, in particular to a high-strength concrete material and a preparation method thereof.According to the high-strength concrete material, through the synergistic effect of core-shell type temperature-sensitive resin particles, a pH response type expanding agent and industrial solid waste composite micro powder, multi-environment self-adaptive crack resistance and mechanical property breakthrough are achieved. The core component is prepared from 180 to 240 parts of cement, industrial solid waste composite micro powder (30 to 50 parts of fly ash-based nano SiO2 and 50 to 70 parts of steel slag micro powder), 10 to 15 parts of core-shell resin particles and 8 to 12 parts of pH response type expanding agent. According to the preparation process, multi-section intelligent stirring (ultra-high-speed shearing and dispersing of the nanometer material) and dynamic maintenance of the internet of things are adopted, the hydration process is precisely regulated and controlled, and the finally prepared material has excellent compressive strength and anti-cracking performance. The method is suitable for severe scenes such as ocean engineering and plateau buildings, and has wide application prospects.

The invention relates to the technical field of building materials, in particular to anti-crack mass concrete and a preparation method thereof, and the concrete is prepared from a gelling system, composite aggregate, a gradient functional additive and water according to a specific ratio. The preparation method is achieved through premixing, gradient stirring and gradient temperature control curing, the three-stage expansion effect of the compound expanding agent is utilized to be matched with the concrete shrinkage process, the hydration heat inhibitor is combined for reducing the temperature peak, basalt fiber is used for reinforcing, and the cracking risk is quantitatively evaluated, so that the 28-day restrained expansion rate of the concrete reaches 0.012% or above, the cracking risk coefficient is smaller than or equal to 0.7, and the concrete has the good crack resistance. The hydration heat peak value is reduced to 48 DEG C or below, and the cement is suitable for engineering of ultra-long structures, large-volume side walls and the like, has no harmful cracks within one year or above, has crack resistance and mechanical properties, and is wide in application prospect.

The invention provides a nano modified composite cementing material, which relates to the technical field of cementing materials, and comprises the following components: slag, construction waste powder, a nano material, an alkali activator and water. By introducing the nano material, the pore structure of the solid waste-based material is remarkably improved, and the gelling capacity, mechanical property and durability of the solid waste-based material are improved. Meanwhile, the material also has relatively strong crack resistance, and the photocatalytic performance and the self-cleaning function of the material can be improved by introducing a functional nano material.

The invention provides a coating for casting an alloy steel lost foam as well as a preparation method and application of the coating. The coating comprises the following raw materials in parts by weight: 79-89 parts of aggregate, 3-7 parts of a binder, 4-7 parts of a suspending agent, 1.5-3 parts of a surfactant, 1.5-2.5 parts of a defoaming agent and 1-1.5 parts of a preservative, the aggregate is prepared from the following components in percentage by mass: 78 to 82 weight percent of bauxite, 12 to 15 weight percent of mica and 3 to 10 weight percent of quartz powder; the binder is prepared from the following components in percentage by mass: 42 to 50 weight percent of anhydrous aluminum dihydrogen phosphate, 18 to 25 weight percent of white carbon black, 12 to 17 weight percent of ethylene glycol and 8 to 28 weight percent of magnesium oxide; the coating for casting the alloy steel evanescent mode keeps good suspension property, high-temperature air permeability, coating property, high-temperature crack resistance and shedding property of the coating, the surface of a casting is smooth and free of burnt-on sand, less harmful gas is volatilized during firing, and harmful gas generated by burning of a white mold can be absorbed.

The invention discloses a cold-mixed and cold-laid ultrathin overlay asphalt mixture which is prepared from the following raw materials in parts by weight: 8-15 parts of rubber powder composite emulsified asphalt; 80 to 90 parts of aggregate; 0.3 to 0.5 part of polymer fiber; 0.5 to 1 part of an interface coupling agent; the invention also provides a construction process of the cold-mixed and cold-laid ultrathin overlay asphalt mixture. The rubber powder composite emulsified asphalt is obtained by emulsifying the composite modified asphalt prepared from the ground rubber powder of the waste tires and the SBS rubber, so that the performance index of the emulsified asphalt is greatly improved, and the bonding performance of a cold-mixed thin-layer asphalt mixture and an original pavement is ensured; in addition, by adding the polymer fibers, the structural strength and the crack resistance of the ultrathin overlay can be remarkably improved. The invention can significantly reduce energy consumption and environmental pollution, and has the advantages of noise reduction, environmental protection, low cost and the like.

The invention discloses a large-span stiff skeleton arch bridge skewback foundation mass concrete crack control method, and relates to the technical field of bridge engineering, and the system comprises the following components: S1, building a collaborative analysis model, S2, analyzing deformation influence, and S3, implementing crack control measures. The method has high pertinence and practicability by adjusting the concrete mix proportion, adding the admixture, setting temperature control measures and optimizing the reinforcement design, the concrete mix proportion and the cement dosage can be adjusted in a targeted mode through the concrete stress distribution condition and the stiff skeleton deformation condition obtained through the collaborative analysis model, and the construction efficiency is improved. The additive is added to reduce the adverse effect of hydration heat, meanwhile, effective temperature control measures are set according to the temperature field distribution condition, in addition, by optimizing the reinforcement design, the bearing capacity and crack resistance of the skewback foundation can be further improved, the crack risk of large-size concrete of the skewback foundation of the large-span stiff skeleton arch bridge is effectively reduced, and the service life of the large-span stiff skeleton arch bridge is prolonged. And the overall quality and safety of a project are improved.

The invention belongs to the technical field of building materials, and particularly discloses maintenance-free lightweight spraying ultra-high performance concrete as well as a preparation method and application of the maintenance-free lightweight spraying ultra-high performance concrete. Comprising 700 to 900 parts of Portland cement, 120 to 200 parts of silica fume, 100 to 200 parts of a layered mineral admixture, 30 to 70 parts of a gradient active expanding agent, 600 to 800 parts of modified lightweight aggregate, 0.5 to 3 parts of a rheology regulating agent, 40 to 80 parts of composite fiber, 7 to 10 parts of a water reducing agent and 170 to 200 parts of water. Based on the synergistic effect of all the components, on the basis that the light ultra-high performance concrete can be continuously sprayed, the spraying performance, the shrinkage performance and the interface bonding performance are further improved, the anti-cracking performance, the mechanical performance and the durability of the light ultra-high performance concrete are enhanced, formwork erecting, film covering maintenance and later maintenance are not needed in construction, and the construction period is shortened. And moreover, the coating has the advantages of small apparent density, strong interface adhesion, thick single-time spraying, high crack resistance, low shrinkage, ultrahigh strength, high durability and the like.

The invention relates to a concrete composition, concrete as well as a preparation method and application of the concrete. The concrete composition comprises the following components: coal gangue aggregate, a gel material and a water reducing agent, the coal gangue aggregate comprises crushed coal gangue, a coarse coal gangue material and coal gangue stone powder, and the average particle size of the coarse coal gangue material is larger than that of the coal gangue stone powder and smaller than that of the crushed coal gangue; the gel material comprises slag, gypsum and carbide slag. According to the concrete composition, the coal gangue of different grades is adopted as the aggregate and compounded with the gel material and the water reducing agent to prepare the concrete, all the raw materials have a synergistic effect, the durability, workability, crack resistance and other performance of the concrete are improved, the production cost is reduced, and the requirement of coal mine construction for high-performance concrete is met.

The invention relates to a composite coating based on modified polyaspartic acid ester, a terrace system and a construction method of the terrace system, and belongs to the technical field of terrace coatings. The composite coating provided by the invention comprises a bottom layer coating, a middle layer coating and a surface layer coating, the prime paint comprises the following components: specific organic silicon modified polyaspartic acid ester prime coat resin; the component of the middle-layer coating comprises specific polyaspartic acid ester floating coat resin; and the component of the surface layer coating comprises specific imide modified polyaspartic acid ester surface coating resin. The invention also provides a terrace system formed after construction of the composite coating, the terrace system has the advantages of crack resistance, compression resistance, moisture resistance, skid resistance, high adhesion, high strength, high wear resistance, yellowing resistance, long service life and the like, does not contain a solvent, avoids environmental pollution caused by volatilization, can keep excellent performance for a long time when being used for outdoor pavements, and has a wide application prospect. The problems of poor applicability, bubbling cracking, yellowing and the like of the existing floor coating in an outdoor severe environment are solved, the application range is wide, and the application value is high.

The invention provides a method for evaluating the crack resistance of tunnel body concrete, and belongs to the technical field of wind tunnels, and the method comprises the steps: uniformly arranging multiple types of sensors on the surface of a tunnel body concrete structure to form a high-density monitoring network, employing a concrete circular ring constraint test piece to establish an anti-crack reference database, and constructing a multi-working-condition temperature stress database; acquiring multi-dimensional data such as strain, temperature and acoustic emission in real time, inputting the monitoring data into a liquid adaptive neural network model to predict crack initiation probability and expansion risk, establishing a crack risk assessment function, formulating a corresponding processing strategy according to a risk coefficient range, and starting an intelligent spray maintenance system; a closed-loop control system from monitoring perception to risk early warning to active protection is formed, and the technical problem that crack initiation and expansion risks of a hole body concrete structure cannot be accurately predicted under complex working conditions is solved.

The invention discloses an environment-friendly deformation-resistant reed wood composite shaving board and a preparation method thereof, and belongs to the technical field of boards. The reed wood composite shaving board is prepared from wood chips, reed fibers, basalt fibers, lignin fibers, plant extracts, nano silicon dioxide, acetylated distarch phosphate, a C30-45 alkyl cetearyl polydimethylsiloxane cross-linked polymer and a PEG-10 polydimethylsiloxane-vinyl polydimethylsiloxane cross-linked polymer according to a specific proportion. The adhesive is prepared from a methyl methacrylate cross-linked polymer, an MDI adhesive and an organic silicon waterproof agent. All the components are matched for use, the shaving board is prepared in a directional mode, the shaving board has excellent mechanical performance, crack resistance and deformation resistance, the environment-friendly performance is improved, and the use amount of glue is reduced. The novel formaldehyde-free adhesive and the plant extract are adopted to replace traditional formaldehyde-containing glue and a mildew-proof and insect-resistant agent, formaldehyde release is effectively avoided, and a healthier home decoration plate choice is provided for consumers.

The invention relates to the field of concrete, and provides high-cracking-resistance concrete and a preparation method thereof.The concrete comprises a surface modified rubber fiber composition, surface modified end-hooked steel fibers, Portland cement, fly ash, silica fume, a superplasticizer, mineral powder, coarse aggregate, fine aggregate and water. The surface modified rubber fiber composition is composed of millimeter-sized and micron-sized rubber fibers, and is subjected to alkali treatment, oxidative sulfonation and amination modification, so that the cement compatibility and interface bonding force of the fibers are improved; the surface modified end-hooked steel fiber is subjected to dopamine hydrochloride auto-polymerization deposition and drying curing treatment, and the reinforcing effect is improved. The preparation method comprises the steps of fiber pretreatment, admixture mixing, aggregate dry mixing, slurry preparation, fiber uniform dispersion and concrete forming maintenance, and material uniformity and performance stability are ensured. By optimizing fiber modification and component proportion, the cracking resistance and durability of the concrete are improved, and the concrete is suitable for high-performance building structures and engineering application.

The invention discloses multi-scale toughened concrete and a preparation method thereof, and belongs to the technical field of high leakage, and the multi-scale toughened concrete comprises aluminoferrite cement, a low-shrinkage auxiliary cementing material, a water reducing agent, multi-scale composite fibers, a shrinkage compensation agent, fine aggregate, coarse aggregate and water. A traditional toughening mode is broken through, a physical-chemical composite connection interface is established through a magnetron sputtering metal gradient coating of crude fibers and a laser-induced dendritic crystal structure, a strain hysteresis effect is triggered under an impact load, impact energy is converted into interface phase change energy, and a high-efficiency energy dissipation channel is formed; an amino functional group and free radical cross-linked network is introduced into the fine fibers, and the fibers are endowed with microcosmic dynamic enhancement capability in combination with directional arrangement of the carbon nanotubes, so that the concrete forms cooperative interaction between macroscopic crack bridging and microcosmic crack inhibition, the crack resistance under complex stress is remarkably improved, and microcrack propagation is effectively inhibited.

The invention belongs to the technical field of motor casing lost foam casting, and particularly relates to a special coating for a motor casing lost foam as well as a preparation method and application thereof. Through a quantitative formula design method, an aggregate proportion calculation formula based on thermal expansion coefficient matching and a grain size distribution correlation formula based on target air permeability, cooperative compounding of quartz powder and bauxite is achieved, and key functional components such as mullite, organic matter fibers and crystalline flake graphite are combined; the unification of high air permeability and excellent crack resistance of the motor shell lost foam coating is realized. The invention further provides a two-time coating gradient drying efficient process matched with the coating, and on the premise that the coating performance is guaranteed, the production efficiency is remarkably improved, and the energy consumption is reduced.

The invention relates to the technical field of building materials, and discloses portland cement-based multi-component concrete and a preparation method thereof.The portland cement-based multi-component concrete is formed by mixing portland cement serving as a base material and fly ash, fiber materials and the like serving as auxiliary materials, and aluminum silicate fibers are modified by using a polymeric macromolecular modifier, so that the strength of the portland cement-based multi-component concrete is improved; the surface of the aluminum silicate fiber is coated with a large number of polymeric macromolecular modifier molecular chains, the whole prepared fiber material is of a micro-dendritic three-dimensional structure, when the fiber material is mixed with cement and other base materials, the micro-dendritic three-dimensional structure can extend to all areas of a cement matrix to form a mortise and tenon joint type structure, and the strength of the fiber material is improved. Therefore, the self-reinforcing effect is efficiently exerted, and the mechanical strength, the crack resistance and the like of the concrete are improved.