2744 results about "Water reducer" patented technology

The invention discloses crack-chloride ion double-triggered subsea tunnel corrosion-resistant concrete and a preparation method thereof, and relates to the field of subsea tunnel engineering materials. The concrete is prepared from the following components in parts by weight: 400 to 500 parts of Portland cement, 50 to 80 parts of fly ash, 60 to 100 parts of superfine mineral powder, 1000 to 1100 parts of coarse aggregate, 700 to 800 parts of fine aggregate, 140 to 160 parts of water, 10 to 20 parts of self-repairing microcapsules and 1 to 5 parts of a water reducing agent, the self-repairing microcapsule comprises a capsule wall material, a self-repairing material and a layered dihydroxyl composite metal oxide. A crack-chloride ion double-response system is constructed, and the limitation of traditional single trigger repair is broken through. When a crack with a certain width appears in the concrete, the capsule wall of the self-repairing microcapsule is broken to release the repairing component, so that effective filling of the crack is realized; and meanwhile, the layered double-metal hydroxide can directionally adsorb chloride ions to form a stable compound, so that the migration rate of the chloride ions is remarkably reduced.

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 discloses a high-toughness impervious polymer modified cement-based grouting material and a preparation method thereof, and belongs to the technical field of building repair materials. The component A is prepared from a cementing material, an admixture, a fine aggregate, a composite expanding agent, a polymer for concrete modification, fibers, an early strength agent, a water reducing agent, a composite retarder, a defoaming agent, an air entraining agent, a nano material and a functional component. The system solves the technical contradiction of toughness-strength-impermeability in the polymer modified cement-based material, and the material has excellent comprehensive performance: the initial fluidity is greater than or equal to 330 mm, the 28d compressive strength is greater than or equal to 82 MPa, the breaking strength is greater than or equal to 16.8 MPa, the bending-compression ratio is greater than or equal to 0.19, the impermeability pressure value is greater than or equal to 2.6 MPa, and the material is suitable for the fields of prefabricated buildings, tunnel engineering and the like.

The invention provides an early-strength rapid-repair grouting material and a preparation method thereof, and the early-strength rapid-repair grouting material is mainly prepared from the following raw materials: 50 to 150 parts of sulphoaluminate cement, 10 to 150 parts of aluminate cement, 200 to 350 parts of a regenerated gelling powder material, 1200 to 1400 parts of quartz sand, 50 to 100 parts of silica fume, 10 to 150 parts of mineral powder, 10 to 100 parts of fly ash, 15 to 50 parts of a composite retarder, 0.1 to 2 parts of a water reducing agent and 1 to 10 parts of an early strength agent. 0.01 to 1 part of a water-retaining agent and 200 to 300 parts of water. The early-strength quick-repair grouting material is characterized in that activated low-cementitious active mineral solid waste is adopted as a main cementitious material, and the product has excellent construction stability, low-carbon weather resistance, corrosion resistance, micro-expansion quick-hardening early strength and economical efficiency.

The invention discloses a high belite sulphoaluminate cement-based two-component grouting material and a preparation method thereof. The grouting material comprises a gelling component and a coagulating reinforcing component, wherein the gelling component is prepared from a high belite sulphoaluminate cement clinker and an additive A; the admixture A comprises a water reducing agent, a retarder and slow-release minerals; the coagulating and reinforcing component comprises ordinary Portland cement clinker, calcium hydroxide, gypsum and an additive B; the admixture B comprises a water reducing agent and an early strength agent. According to the high belite sulphoaluminate cement-based grouting material, the formula composition of the high belite sulphoaluminate cement-based grouting material is optimized, so that the hydration process of the high belite sulphoaluminate cement is more continuous and lasting, and the compressive strength of the obtained high belite sulphoaluminate cement-based grouting material can be continuously improved.

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 relates to the technical field of concrete, and particularly discloses super-retarded concrete for an ultra-large pile and a preparation method of the super-retarded concrete. The super-retarding concrete for the ultra-large pile is prepared from the following raw materials in parts by mass: 320 to 400 parts of a cementing material, 1820 to 1960 parts of aggregate, 20 to 28 parts of an inorganic-organic hybrid retarding reinforcing agent, 7.2 to 11.6 parts of a polycarboxylate superplasticizer and 85 to 98 parts of water, the inorganic-organic hybrid delayed coagulation enhancer is prepared by carrying out in-situ free radical polymerization reaction on a hydroxyl acrylate monomer, acrylamide and nano silicon dioxide. According to the inorganic-organic hybrid retarding reinforcing agent, a hybrid substance is formed through a chemical bond, an organic phase is chelated with calcium ions to realize retarding and does not excessively inhibit cement particles, inorganic phase nano silicon dioxide has no agglomeration risk, gaps are filled, a stable product is generated to resist alkali erosion, and the super retarding performance and the long-term strength of concrete are both considered; and the service life of the ultra-large pile is prolonged.

The invention belongs to the technical field of cement pole materials, and particularly relates to a high-strength cement pole material and a preparation method thereof. The high-strength cement pole material is prepared from the following components in parts by weight: 450 to 500 parts of cement, 60 to 80 parts of fly ash, 500 to 550 parts of fine aggregate, 800 to 1000 parts of coarse aggregate, 80 to 120 parts of slag powder, 30 to 50 parts of composite fiber, 5 to 10 parts of redispersible latex powder, 2 to 6 parts of water reducing agent and 100 to 150 parts of water, the composite fibers comprise modified basalt fibers and polypropylene reticular fibers. According to the high-strength cement pole material provided by the invention, the polypropylene reticular fibers and the specific modified basalt fibers act together, so that the cement pole material has high compressive strength and high breaking strength, and a cement pole prepared from the cement pole material has high flexural capacity.

The invention discloses a preparation process of a waste concrete recycled aggregate gypsum-based wall material, which comprises the following steps: (1) mixing a water repellent agent with an anhydrous solvent to obtain a pretreating agent, and then adding concrete recycled aggregate for standing; and separating out the recycled aggregate and drying the recycled aggregate to obtain the pretreated recycled aggregate. (2) calcining the magnesium oxide whisker, and then adding the obtained calcined whisker into an ethanol solution of polyethylene glycol to form a suspension; and spraying the suspension on the continuously stirred pretreated recycled aggregate, and then carrying out heating and stirring treatment to obtain the modified recycled aggregate. And (3) uniformly stirring ardealite powder, silica fume, potassium hydroxide powder and fine aggregate, then adding water, a retarder and a water reducing agent, uniformly stirring, then adding the modified recycled aggregate, and uniformly stirring, thereby obtaining the product. The process provided by the invention not only reduces the adverse effect of the recycled aggregate on the gypsum-based material, but also improves the water resistance of the gypsum-based material and enhances the mechanical strength.

The invention discloses multi-source composite expansion super-early-strength concrete and a preparation method thereof. The concrete comprises a cementing material, aggregate, a water reducing agent, water and a multi-source composite expansion system. The expansion system is composed of a plastic expansion agent, a calcium sulphoaluminate early expansion source, a magnesium oxide delayed expansion source and an internal curing material. Through precise component design and function time sequence matching, a cooperative compensation network covering the whole life cycle of the concrete is constructed, a plastic expanding agent inhibits plastic shrinkage, calcium sulphoaluminate compensates early-stage self-shrinkage, magnesium oxide resists medium-and-long-term drying shrinkage, an internal curing material provides continuous moisture guarantee for the above process, and the overall performance of the concrete is improved. And the efficiency of each expansion source is excited and coupled. According to the invention, seamless and accurate shrinkage compensation from a plastic stage to a service later stage can be realized on the premise of ensuring the super early strength characteristic of the concrete, the technical problem that the super early strength concrete is easy to crack due to severe shrinkage is fundamentally solved, and the volume stability and durability of the structure are remarkably improved.

The invention relates to the technical field of concrete materials, and discloses rapidly-reinforced high-performance sprayed concrete for an existing tunnel lining and a preparation method of the rapidly-reinforced high-performance sprayed concrete. The sprayed concrete is prepared from the following raw materials in parts by weight: 300 to 350 parts of low-calcium high belite sulphoaluminate cement, 80 to 100 parts of superfine slag powder, 3 to 8 parts of a trigger type activating agent, 5 to 15 parts of slow-release particles, 2 to 5 parts of nanogel, 800 to 900 parts of fine aggregate, 800 to 900 parts of coarse aggregate, 30 to 50 parts of copper-plated steel fiber, 0.8 to 1.2 parts of polypropylene fiber, 30 to 40 parts of a viscosity-adjusting accelerator, 10 to 20 parts of a water reducing agent and 160 to 180 parts of water. The sprayed concrete is high in compressive strength and good in durability, the double threats of chemical corrosion and chloride ion permeation / steel bar corrosion are cooperatively solved, and the requirement for rapid reinforcement of tunnels and underground engineering is met.

The invention belongs to the technical field of concrete, and particularly relates to dynamic carbon injection recycled coarse aggregate concrete as well as a preparation method and application thereof. The preparation method of the concrete comprises the following steps: (1) adding the cement, the mineral powder, the recycled coarse aggregate, the fine aggregate, the fly ash, the carbon sequestration agent, the retarder and the water reducing agent into water, and uniformly stirring to obtain a mixed material; (2) injecting carbon dioxide into the mixed material to obtain carbon-mixed concrete; and (3) curing the carbon-mixed concrete to obtain the carbon-mixed concrete. The invention provides a method for preparing dynamic carbon injection recycled coarse aggregate concrete by taking a carbon sequestration agent, a retarder, cement, mineral powder, recycled coarse aggregate, fine aggregate, fly ash and a water reducing agent as raw materials. The method is simple in process and easy for large-scale production. The concrete prepared by adopting the method is relatively high in carbon sequestration rate, excellent in mechanical property and capable of effectively avoiding rapid hydration.

The invention relates to the technical field of building materials, and provides washing gangue concrete with high slump loss resistance and a mixing process thereof. The high-slump-retaining washed gangue concrete is prepared from the following raw materials in parts by weight: 200 to 220 parts of cement, 140 to 150 parts of mineral powder, 60 to 65 parts of fly ash, 680 to 720 parts of machine-made sand, 950 to 970 parts of washed gangue, 150 to 160 parts of water, 16 to 17.5 parts of a water reducing agent, 0.15 to 0.3 part of a slump retaining agent and 4 to 4.3 parts of polyethylene glycol. The slump retaining agent is hydroxypropyl methyl cellulose ether; and the viscosity of the hydroxypropyl methyl cellulose ether is 100 thousand mPa.s to 300 thousand mPa.s. According to the technical scheme, the problems of poor slump retaining performance and low compressive strength of washed gangue concrete in the prior art are solved.

The invention discloses solid waste-based fiber reinforced sprayed concrete and a preparation method thereof, and belongs to the technical field of concrete. The sprayed concrete is prepared from the solid waste-based cementing material, the fine aggregate, the basalt fiber, the water reducing agent, the accelerator and the water, the slag, the carbide slag, the fly ash and the cement serve as the solid waste-based cementing material, part of the cement is replaced by the fly ash and the slag, the slag can make up for the deficiency of the activity of the fly ash in the early stage, the early strength is rapidly improved, and the early strength is improved. The rebound rate is reduced; the fly ash further densifies the matrix in the later period by means of continuous pozzolanic reaction, so that the durability is enhanced; the basalt fibers, the accelerator and the water reducing agent are mixed, the hydration process is optimized, and the synergistic enhancement effect of the fibers and a matrix is achieved, so that the generation of early cracks and the development of later cracks are inhibited, and finally the sprayed concrete with high strength, high toughness and low shrinkage is obtained.

The invention discloses ceramsite lightweight aggregate structural concrete and a preparation method thereof, and belongs to the technical field of concrete. The ceramsite lightweight aggregate structural concrete is prepared from the following raw materials in parts by mass: 240 to 270 parts of cement, 25 to 35 parts of mineral powder, 80 to 95 parts of fly ash, 210 to 250 parts of coal gangue crushed materials, 725 to 805 parts of modified coal gangue ceramsite, 10 to 30 parts of waste rubber materials, 3.5 to 5 parts of water reducing agents and 165 to 180 parts of water. The modified coal gangue ceramsite is obtained by coating the surface of a coal gangue ceramsite matrix with an epoxy resin layer and then grafting a hydrophilic polymer, the porosity of the coal gangue ceramsite matrix is 40-60%, and the aperture ratio is 1.5-6%. The epoxy resin layer on the surface of the modified coal gangue ceramsite provides an anti-permeability barrier, the hydrophilic polymer on the surface adjusts the wettability of the ceramsite, the binding force with other components of the concrete is improved, and the concrete has excellent shrinkage and dry crack resistance.

The invention relates to a polycarboxylate superplasticizer compounding production line. The production line comprises an intelligent raw material pretreatment unit, a multi-component precise proportioning unit, a gradient temperature control compounding reaction unit, an online quality monitoring feedback unit and a finished product self-adaptive filling unit which are connected in sequence. The multi-component precise proportioning unit is internally provided with a dynamic proportioning adjusting system, and the feeding amount can be corrected according to the solid content deviation of raw materials and the target fluidity; the gradient temperature control compound reaction unit realizes temperature and speed coordinated regulation and control through a sectional temperature control module and a stirring speed linkage device; and the online quality monitoring feedback unit forms closed-loop control with the above two units by means of a near infrared spectrum detection module. The invention aims to solve the problem that the existing production line lacks the dynamic ratio adjustment of the actual solid content deviation of the raw material and the target fluidity, the reaction stage temperature control and stirring rate cooperative regulation and control and the online detection closed-loop control; therefore, the problems of low proportioning precision, poor reaction process controllability and large performance fluctuation of the water reducing agent are solved.

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

The invention discloses 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 belongs to the technical field of building materials, and particularly relates to a micro-expansion anti-cracking waterproof composite deep groove filler and a preparation method thereof. The micro-bulking anti-cracking waterproof composite deep groove filler provided by the invention comprises cement, gypsum, mineral powder, nano silicon oxide, coarse aggregate, fine aggregate, modified fibers, an expanding agent, a polycarboxylate superplasticizer and water. According to the invention, polyacrylamide, calcium sulphoaluminate and magnesium oxide are adopted to jointly form an expanding agent, and early-stage-late-stage full-period shrinkage compensation is jointly formed in a concrete hydration process, so that the density of the concrete is effectively improved, and the waterproof performance of the concrete is further improved; according to the invention, sodium dodecyl benzene sulfonate and propylene glycol block polyether are adopted to carry out compound modification on graphene oxide, and gamma-aminopropyltriethoxysilane is connected to the surface of basalt fiber, so that the bonding strength of basalt fiber and a cement matrix and the compactness of the cement matrix are improved, and the waterproof and anti-cracking properties of concrete are further improved.

The invention discloses a super-early-strength shrinkage-free high-crack-resistance tunnel spraying repair material in the technical field of civil engineering materials, which comprises the following raw materials in percentage by mass: 35-45% of sulphoaluminate cement; 8%-12% of a superfine early strength admixture; 2%-3% of a calcium sulphoaluminate expanding agent; 1%-2% of a magnesium oxide-based expanding agent; 1-2% of a calcium-magnesium composite expanding agent; 10%-15% of hollow glass beads; 1.5%-2.5% of copper plated steel fiber; 0.1%-0.3% of polypropylene fiber; 25%-30% of graded quartz sand; 0.5%-1.0% of a polycarboxylic acid water reducing agent; 3%-5% of an alkali-free liquid accelerator; 0.3%-0.8% of a thixotropic agent; and 0.1%-0.3% of a thickening time control agent. According to the method, a multi-scale performance cooperative regulation system is innovatively constructed. Through accurate control of the hydration process of a gel system, a shrinkage stress multi-stage compensation mechanism and systematic integration of a fiber-matrix interface strengthening technology, the mutual restriction relationship among early strength development, volume stability and crack resistance of a traditional material is broken through.

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 relates to the technical field of building materials, in particular to light water-resistant phosphogypsum-based cement concrete mortar and a preparation process thereof. The phosphogypsum-based cement concrete mortar comprises the following components: activated phosphogypsum, sulphoaluminate cement, magnesium phosphate cement, modified zeolite powder, lightweight aggregate, modified nano silicon dioxide, a core-shell toughening agent, a polycarboxylate superplasticizer and water, and the preparation method comprises the following steps: respectively preparing the activated phosphogypsum, the modified zeolite powder, the modified nano silicon dioxide and the core-shell toughening agent; the water resistance of the ardealite is improved through activating treatment, the interface bonding force and the structural compactness are enhanced through multi-component synergism by means of selective adsorption of the modified zeolite powder, the mechanical property of the lightweight aggregate is optimized, the toughness is improved through the core-shell toughening agent, and lightweight, high water resistance, stable performance and durability improvement of the mortar are achieved; the requirements of complex building scenes are met, and environment-friendly and practical values are achieved.

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

The invention discloses low-carbon red-mud-based alkali-activated foam concrete and a preparation method thereof, and belongs to the field of low-carbon foam concrete. Specifically, the mix proportion and the preparation method of the low-carbon red-mud-based alkali-activated foam concrete are as follows: P.O42.5 ordinary Portland cement provided by building materials in Qingdao Weidong macro, the I-grade fly ash is S95-grade granulated blast-furnace slag produced by Henan Province Platinon Casting Material Co., Ltd., and Jinshu New Material Co., Ltd., the I-grade fly ash is S95-grade granulated blast-furnace slag produced by Henan Province Platinon Casting Material Co., Ltd. The Bayer process red mud powder is produced by Hebei Province Shihozhuangfei Mine Product Co., Ltd. The exciting agent is selected from an industrial liquid sodium silicate solution produced by Henan Jinmoistening New Material Co., Ltd. And solid sodium hydroxide particles with AR analytical purity of 96%; the admixture is selected from a TR-26C type polycarboxylate superplasticizer produced by Henan Fuhua Information Science and Technology Co., Ltd. And the foaming agent is a TR-E type animal protein foaming agent produced by Henan Zhuichun Information Science and Technology Co., Ltd. Compared with existing foam concrete, the low-carbon alkali-activated foam concrete provided by the invention uses a large amount of industrial solid waste, reduces the use cost, reduces the use amount of cement under the condition of ensuring the compressive strength, and is simple and convenient to operate, reasonable in process, low-carbon, environment-friendly, rapid in cement setting and hardening, and suitable for large-scale use.

The invention relates to the technical field of hydraulic concrete materials, and particularly discloses nano-modified anti-rebound full-hole slag sprayed concrete, which is prepared from the following raw materials in parts by weight: 665 parts of hole slag aggregate, 950 parts of hole slag sand, 396 to 436.5 parts of ordinary Portland cement, 225 parts of water, 10 parts of polycarboxylic acid type water reducing agent and 8.5 parts of accelerator, the hole slag aggregate is further modified by a nano admixture, and the nano admixture is composed of nano kaolin, nano silicon dioxide and a precise PCE solution. The springback-resistant shotcrete is prepared from the nano admixture modified hole slag aggregate, full-quantitative resource utilization of tunnel excavation hole slag is achieved, the problems of occupied area of piled slag and potential ecological pollution are effectively relieved, the cement consumption in the concrete is reduced, the construction cost is reduced, meanwhile, the springback rate of the shotcrete can be remarkably reduced, and the construction period is shortened. The compactness of the concrete is improved, and the compression resistance degree and the crack resistance of the concrete are enhanced.

The application discloses a self-repairing crystal anti-permeation high-durability cement-based material, a cement-based surface structure and a paving method thereof. The self-repairing crystal anti-permeation high-durability cement-based material comprises the following components in parts by weight: Portland cement 40-60 parts, wear-resistant aggregate 35-50 parts, water reducing agent 0.02-0.05 parts, retarder 0.2-0.5 parts, redispersible emulsion powder 1-2 parts, silica fume 1-2 parts, expanding agent 1-3 parts, chelating agent 1-6 parts and crystallization precipitant 1-6 parts; the total amount of the above components is 100 parts; the chelating agent is diethylenetriamine pentaacetic acid, and the weight ratio of the chelating agent to the crystallization precipitant is (0.5-2):1. The cement-based material has excellent self-repairing property, so that the strength, durability and anti-permeation property of the cement-based material are significantly improved.

The invention relates to the technical field of concrete, and provides anti-crack concrete and a preparation method thereof.The anti-crack concrete is prepared from, by weight, 280-350 parts of cement, 50-80 parts of mineral admixture, 1000-1200 parts of gravel, 650-850 parts of sand, 6.0-10.0 parts of water reducing agent, 16-20 parts of expanding agent, 10-25 parts of fiber and 140-160 parts of water; the fiber is a nano-modified PVA fiber and is formed by grafting SiO2 nano-particles with the particle size of 20 nm on the surface of the PVA fiber, and the grafting amount is 3%-5%. The PVC fibers are subjected to nano modification, SiO2 nanoparticles with the particle size of 20 nm are grafted to the surfaces of the PVC fibers, a low-surface-energy dispersion layer is formed on the surfaces of the PVA fibers, the agglomeration resistance of the PVA fibers is improved, agglomeration generated when the PVC fibers are used for preparing the anti-crack concrete is reduced, and then the anti-crack performance of the concrete is improved.