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60 results about "Shrinkage cracking" patented technology

Low-temperature high-durability magnesium phosphate cement and preparation method thereof

According to the low-temperature high-durability magnesium phosphate cement and the preparation method thereof, dead burned magnesia powder serves as a core gelling base material and can provide a large amount of active Mg < 2 + >, ammonium dihydrogen phosphate can provide an acid environment and PO4 < 3->, the dead burned magnesia powder and the ammonium dihydrogen phosphate are subjected to an acid-base neutralization reaction in the presence of water to generate ammonium magnesium phosphate hydration products, and the magnesium phosphate hydration products are subjected to a low-temperature high-durability magnesium phosphate cement. The products are interwoven to form a hardened body framework, and a strength foundation is laid for cement; borax is adopted as a key retarder, borate ions generated after the borax is dissolved in water can be adsorbed on the surfaces of dead burned magnesia powder particles, a magnesium borate complex film is formed, the dissolution of Mg < 2 + > and the reaction of PO4 < 3-> are hindered, the cement setting time is effectively delayed, and the construction requirements are met; and the borax can also refine the crystal structure of a hydration product, reduce the porosity, improve the impermeability and the volume stability of a hardened body, and avoid shrinkage cracking.
Owner:CHANGAN UNIV

Honeycomb filling aerogel thermal insulation material and preparation method thereof

The method comprises the following steps: preparing an aluminum oxide nanowire precursor with a certain length-diameter ratio by a hydrothermal method, mixing the aluminum oxide nanowire precursor with silicon dioxide nano powder and ceramic fibers, filling the mixture into a honeycomb, and carrying out compression molding, curing, ethanol solvent replacement, subcritical drying and other process steps to obtain the honeycomb filled aerogel thermal insulation material. The honeycomb filled aerogel heat insulation material is successfully prepared. According to the preparation method disclosed by the invention, efficient preparation of the aerogel-filled honeycomb material with controllable filling density and excellent mechanical strength is realized by regulating and controlling a micro-nano hierarchical structure and mixed components. The aerogel is combined with the honeycomb, and the aluminum oxide nanowire cluster and the ceramic fiber are introduced as inorganic components, so that the shrinkage cracking of the aerogel at high temperature is inhibited, and the structural stability and the mechanical property of the material at high temperature are remarkably improved.
Owner:BEIHANG UNIV

Construction waste recycled aggregate concrete and preparation method thereof

The invention relates to construction waste recycled aggregate concrete and a preparation method thereof, relates to the technical field of concrete, and improves the workability and durability of the concrete by reasonably proportioning a modified water reducing agent with other raw materials. Wherein the modified water reducing agent is prepared by carrying out primary esterification on maleated rosin and a monomer containing hydroxyl, then carrying out dicarboxylation on the modified water reducing agent and sulfonating the modified water reducing agent through sulfite, has a hydrophobic skeleton and carboxyl and sulfonic acid double hydrophilic groups, and can strongly adsorb cement particles, form a static electricity and steric hindrance double effect, disperse a cement binding material and release water; and workability loss and shrinkage cracking caused by high water absorption of the recycled aggregate are inhibited. The concrete prepared by the invention has the advantages of good water reducing property, good strength and difficulty in collapsing.
Owner:GUANGZHOU CHANGYUN READY-MIXED CONCRETE CO LTD

A solid waste-based nano-hydrated calcium silicate nucleating agent, its preparation method, and its application in low-heat cement.

A solid waste-based nano-hydrated calcium silicate nucleating agent, its preparation method, and its application in low-heat cement are disclosed. This invention belongs to the field of building materials technology. By weight, it comprises the following components: 10-30 parts of carbide slag, 20-45 parts of yellow phosphorus slag, and 400-2000 parts of sodium hydroxide solution. The calcium hydroxide content in the carbide slag is ≥80%. The silicon dioxide content in the yellow phosphorus slag is ≥35%, and the calcium oxide content is ≥40%. The pH value of the sodium hydroxide solution is 11-12. This invention uses carbide slag, yellow phosphorus slag, and sodium hydroxide solution as raw materials to synthesize a solid waste-based nano-hydrated calcium silicate nucleating agent. Utilizing its nano-sized hydrated calcium silicate as a seed crystal in the early stage of hydration in low-heat cement, it can provide nucleation sites for the hydrated calcium silicate gel, a product of low-heat cement hydration, reducing the nucleation barrier of the hydrated calcium silicate gel, promoting the hydration rate and early strength development of low-heat cement, and providing strong support for the later strength development of low-heat cement, effectively improving the problem of drying shrinkage cracking in low-heat cement.
Owner:CHINA BUILDING MATERIALS ACADEMY CO LTD +2

Low-shrinkage lightweight high-strength alkali-activated foam concrete and preparation method and application thereof

The application discloses low-shrinkage light-weight high-strength alkali-activated foam concrete and a preparation method and application thereof. The raw material composition of the foam concrete comprises 30-80 parts by weight of slag powder, 40-120 parts by weight of mineral admixture, 2-15 parts by weight of porous filler, 5-20 parts by weight of sodium-potassium water glass, 0.5-10 parts by weight of foaming agent and 0.5-5 parts by weight of anti-shrinkage agent. The anti-shrinkage agent is prepared by the following method: placing water-absorbing resin in a saturated shrinkage reducing agent solution, keeping under heating conditions, making the water-absorbing resin reach a saturated water state, and then separating the water-absorbing resin and draining the liquid to obtain the anti-shrinkage agent. The application not only reduces the self-shrinkage degree of the alkali-activated foam concrete, overcomes the shrinkage and cracking problem of the foam concrete during service, but also increases the compressive strength of the alkali-activated foam concrete.
Owner:UNIV OF JINAN

Circulating fluidized bed ash-based road base cementing material and preparation method thereof

PendingCN122079568AReduced hydrationlow costShrinkage crackingSlag
This invention belongs to the field of industrial solid waste resource utilization technology, and relates to a circulating fluidized bed ash-based cementitious material for road base courses and its preparation method. The raw materials for the road base course cementitious material are composed of the following mass parts: 29-43 parts of circulating fluidized bed ash, 16-27 parts of ground blast furnace slag, 3-6 parts of silica fume, 7-15 parts of P.O42.5 silicate cement, 0.1-0.4 parts of activator, and 27-30 parts of water. The circulating fluidized bed ash is prepared by mixing circulating fluidized bed fly ash and slag in a mass ratio of (2-5):(5-10). This invention effectively alleviates the problems of fast setting time and shrinkage cracking of traditional road base course cementitious materials by utilizing the characteristics of micro-expansion and long hydration time of circulating fluidized bed ash. The advantage of this invention is that it promotes the large-scale utilization of circulating fluidized bed ash and contributes to carbon emission reduction in the road sector.
Owner:SHANXI UNIV

Solid waste-based geopolymer and preparation method thereof

The invention relates to the technical field of solid waste material recycling, in particular to a solid waste-based geopolymer and a preparation method thereof. The solid waste-based geopolymer comprises the following components in parts by mass: 400-500 parts of fly ash; 400 to 500 parts of mineral powder; 40-60 parts of a sodium hydroxide aqueous solution; 200 to 400 parts of water; the solid content of the nano waterborne epoxy emulsion is 30-62%, the particle size of the nano waterborne epoxy emulsion is 100-900 nm, and the nano waterborne epoxy emulsion accounts for 3-9% of the total mass. According to the invention, the compactness of a matrix is enhanced, shrinkage cracking caused by water evaporation is reduced, the toughness and anti-permeability of the material are improved, the compactness of an interface is enhanced, the saltpetering condition of the matrix is inhibited, and wide application in the field of building materials is facilitated.
Owner:UNIV OF JINAN +1

Seam filling and leveling anti-cracking structure for window frame with large rabbet and window frame structure

The utility model discloses a seam filling and leveling anti-cracking structure for a window frame with a large rabbet and a window frame structure, and relates to the field of doors and windows. The seam filling and leveling anti-cracking structure for the window frame with the large rabbet comprises a concrete wall body with a hole and the window frame connected to the inner wall of the hole, the concrete wall body protrudes to form an inner side wall pier, and a seam with an L-shaped cross section is defined by the end face and the side face of the window frame, the concrete wall body and the inner side wall pier; the gap is filled with a light cement-based mortar leveling layer, and a waterproof layer and an outer sealing layer which extend to the side face of the window frame are sequentially arranged at the end, away from the inner side wall pier, of the light cement-based mortar leveling layer. The seam filling and leveling anti-cracking structure for the window frame with the large rabbet and the window frame structure have the advantages of being convenient to construct, high in construction efficiency and low in construction cost, and shrinkage, cracking and leakage of the seam filling position of the window frame can be avoided.
Owner:HUAXIN CEMENT CO LTD

Curing method for inhibiting drying shrinkage cracking of cured sludge

The invention discloses a curing method for inhibiting drying shrinkage cracking of cured sludge, and belongs to the technical field of crack prevention of cured sludge in geotechnical engineering. The artificial fine aggregate for inhibiting the cured sludge from drying shrinkage cracking is prepared from the following raw materials in parts by mass: 60 to 70 parts of gypsum powder, 20 to 30 parts of blast furnace slag, 2 to 10 parts of calcium carbide dust, 4 to 8 parts of cement and 0.5 to 1 part of sodium dodecyl benzene sulfonate. After the artificial fine aggregate disclosed by the invention is mixed into sludge, not only can the grading of the sludge be improved, but also the curing hydration reaction can be promoted to be continuously carried out by adsorbing free water through the porous structure, so that the dry shrinkage deformation of the cured sludge is compensated, and the dry shrinkage cracking resistance and the anti-seepage performance of the cured sludge can be improved. According to the invention, the artificial fine aggregate is prepared from a large mixing amount of industrial waste residue, and is mixed into the sludge to be cured, and the dry shrinkage deformation of the cured sludge is inhibited through grading improvement, free water adsorption, self volume expansibility and strength increase.
Owner:JIANGSU HAIGU JIYE TECHNOLOGY CO LTD +1

High-water-retention anti-cracking all-solid waste sludge-based foam light fluid soil and preparation method thereof

The invention discloses high-water-retention and anti-cracking all-solid waste sludge-based foam light-weight fluid-state soil and a preparation method thereof, and belongs to the technical field of solid waste resource utilization and civil engineering filling materials, the high-water-retention and anti-cracking all-solid waste sludge-based foam light-weight fluid-state soil comprises aggregate, an alkali-activated gelling system, a water-retention and anti-cracking agent and light-weight filler, the aggregate comprises high-water-content sludge, and the alkali-activated gelling system comprises water-retaining and anti-cracking the alkali-activated gelling system comprises fly ash, red mud, steel slag and an alkali activator, the water-retaining anti-cracking agent comprises xanthan gum, the light filler comprises foam, layered pouring is performed during construction, a foam-stabilizing anti-collapse layer is arranged between two layers of fluid-state soil, and a water-retaining anti-cracking layer is sprayed on each layer. According to the invention, the problems of large cement consumption, high carbon emission and easy dry shrinkage and cracking in the traditional foam light fluid soil are effectively solved, and the water-retaining property and the crack resistance of the material are obviously improved; meanwhile, a cement-like gel structure is formed through solid waste synergistic excitation, efficient resource utilization of the waste sludge is achieved, and the engineering cost and the environmental burden are reduced.
Owner:SOUTHEAST UNIV

A method for improving the crack resistance of ultra-high performance concrete structures

This invention discloses a method for improving the crack resistance of ultra-high performance concrete structures, relating to the field of concrete materials. The invention involves bonding polylactic acid (PLA) fibers and metal fibers with polyurethane adhesive to form a composite fiber. After treatment with polyurethane adhesive, the composite fiber forms a three-dimensional support network, which is alternately laid with a fine slag layer to form a gradient structure, effectively inhibiting the initiation and propagation of microcracks. The cementitious system, combined with composite admixtures, reduces the heat of hydration, and the micropores of the fine slag buffer shrinkage stress, significantly reducing shrinkage cracking. The self-healing microcapsules loaded with fine slag are uniformly dispersed, releasing a repair agent when cracks occur, rapidly healing microcracks, significantly restoring mechanical properties and impermeability, and improving durability. Furthermore, under the alkali-activated effect during the PLA fiber curing process, the fine slag can bond tightly with the composite fiber, achieving a synergistic "crack prevention-repair" effect, adapting to the construction of complex components, reducing material costs, shortening the curing cycle, and significantly reducing the total life-cycle cost.
Owner:SHANDONG EXPRESSWAY INFRASTRUCTURE CONSTR CO LTD +3

A composite solidifying agent for construction waste recycled fluidized solid soil and a preparation method thereof

PendingCN122403901AAluminateBrick
The present application relates to the field of solidifying agent, and more particularly to a kind of composite solidifying agent for construction waste recycled material flow state solidified soil and preparation method thereof, comprising the following raw materials: sulphoaluminate cement 20-30 parts, slag powder 15-25 parts, recycled brick powder 10-15 parts, amino-terminated hyperbranched polymer 4-7 parts, silane coupling agent 2-4 parts, urease composite material 2-3 parts, urea microspheres 1-3 parts, calcium chloride 0.5-2 parts, construction waste recycled micro powder 10-18 parts, fly ash 5-10 parts.The solidifying agent solves the technical problems of weak interface in construction waste recycled material flow state solidified soil, enzyme activity easy deactivation, large strength fluctuation, serious shrinkage and cracking and the like through multi-component synergistic effect.
Owner:CHONGQING ZHIDI ENVIRONMENTAL PROTECTION TECHNOLOGY CO LTD

A method for preparing a silicon nitride wear-resistant coating on the surface of a graphite member

PendingCN122355738AShrinkage crackingCrack free
This invention relates to a method for preparing a silicon nitride wear-resistant coating on the surface of a graphite part. The method involves coating the graphite part with polynitrosilane, followed by drying and subsequent decoking and high-temperature ceramization treatments. The process is precisely designed as a multi-stage heating decoking and high-temperature ceramization process. By strictly controlling the heating rate and holding time, the method avoids coating shrinkage and cracking caused by rapid heating, as well as resource waste and increased internal stress caused by excessively slow heating. Simultaneously, the decoking temperature is optimized to prevent excessive decomposition and escape of polynitrosilane or residual small molecules. This effectively solves the coating cracking problem caused by the difference in thermal expansion coefficients between graphite and silicon nitride, thereby obtaining a dense, uniform, and crack-free silicon nitride coating.
Owner:SHAANXI UDC MATERIALS TECH CO LTD

Low-density alkali slag foamed concrete and preparation method thereof

The invention discloses low-density alkali slag foamed concrete and a preparation method thereof, and belongs to the technical field of concrete. Comprising 100 parts of a gelling base material, 18-22 parts of a composite alkali activator, 4-7 parts of a controlled-release foaming agent, 1-2 parts of a composite foam-stabilizing anti-shrinkage agent, 0.4-0.6 part of a bonding enhancer, 0.05-0.1 part of a bio-based delayed coagulation regulator and 0.2-0.3 part of a foaming-foam-stabilizing regulator. The preparation method comprises the following steps: mixing the gelling base material, the composite alkali activator, the bonding enhancer and the bio-based delayed coagulation regulator, adding water to prepare base slurry, sequentially adding the composite foam-stabilizing anti-shrinking agent, the foaming-foam-stabilizing regulator and the controlled-release foaming agent, and stirring until the slurry is foamed; and pouring the slurry into a mold for molding, and curing for molding. The concrete provided by the invention can realize balance of low density and mechanical properties, improves shrinkage cracking resistance, water resistance and fitting performance with an old base layer, adapts to old building reconstruction scenes with high humidity, temperature and humidity fluctuation and poor base layer flatness, is high in construction adaptability, and can guarantee the structural stability and long-term use reliability after reconstruction.
Owner:绵竹市铸诚混凝土有限公司

Ultrathin UHPC (Ultra High Performance Concrete) planting frame and preparation method thereof

The invention discloses an ultrathin UHPC (Ultra High Performance Concrete) planting frame and a preparation method thereof. The ultrathin UHPC planting frame comprises a bearing frame and an edge frame, the edge frames are arranged on the two sides of the bearing frame, the bearing frame comprises a bottom contact plate, an inclined supporting plate and a top contact plate, the bottom contact plate, the inclined supporting plate and the top contact plate are sequentially arranged between the edge frames to form a wave groove structure, and water permeable holes can be formed in the bottom contact plate; according to the scheme, through a fiber synergistic reinforcement and shrinkage compensation system, the breaking strength of the planting frame is larger than or equal to 30 MPa, the compressive strength is larger than or equal to 125 MPa, the fracture rate is reduced to 0, the shrinkage rate is smaller than or equal to 0.02%, and the core problems of brittle fracture and shrinkage cracking of an ultrathin wall body are solved; and after 10 times of cold and heat cycles (-20 DEG C to 60 DEG C), no crack or fracture is generated, the number of freeze-thaw cycles is larger than or equal to 300, and the performance of the planting frame is far better than that of an existing planting frame.
Owner:SICHUAN CHINA STRUCTURE RESIDENTIAL IND

Fly ash-based fluidified solidified material, and preparation method and application thereof

This invention discloses a fly ash-based fluidized solidification material, its preparation method, and its application. The fluidized solidification material is obtained by curing fly ash with a curing agent composed of an alkali-activated material, a cementing material, a water-reducing agent, and a filler. The alkali-activated material is sodium hydroxide or carbide slag; the cementing material is granulated blast furnace slag powder; the filler is desulfurized gypsum; and the water-reducing agent is sodium hexametaphosphate, magnesium lignosulfonate, or a mixture of both. The alkali-activated material has a synergistic activating effect on the Ca-Si-Al active components in the cementing material, promoting the formation of hydrated calcium silicate gel and ettringite crystal phases, strengthening the material's mechanical properties, and increasing the density of the pore structure. The water-reducing agent optimizes the hydration reaction process, reduces the water-ash ratio, and inhibits the system's tendency to shrink and crack. The desulfurized gypsum partially replaces the alkali-activated material, filling the material's pores, improving the material's unconfined compressive strength, and reducing the material's permeability coefficient. It can be used as an ex-situ barrier material with excellent mechanical properties, impermeability, and durability.
Owner:SOUTHEAST UNIV +1

Quick-drying aerogel thermal insulation material and preparation method thereof

The preparation method comprises the following steps: preparing an aluminum oxide nanowire ball with a certain length-diameter ratio by adopting a solvothermal method, performing high-shear mixing on the aluminum oxide nanowire ball, silicon resin, a silane coupling agent and quartz fibers to form a multi-stage enhanced network, and performing compression molding, curing, subcritical drying and other process steps to obtain the aerogel thermal insulation material capable of being quickly dried. The inorganic-organic hybrid aerogel thermal insulation material with high temperature resistance is successfully prepared. Through collaborative optimization of in-situ compounding of organic and inorganic components and subcritical drying, efficient preparation of the aerogel with low cost and good mechanical strength is realized. The aluminum oxide nanowire clusters and the quartz fibers are introduced as inorganic components, effective support is provided, shrinkage cracking does not occur in the silicon resin pyrolysis process, and the structural stability and ablation resistance of the material at high temperature are remarkably improved.
Owner:BEIHANG UNIV

Construction method and device for resisting shrinkage cracking of tunnel wall concrete

The invention relates to the technical field of underground tunnel engineering construction, in particular to a construction method and device for resisting shrinkage cracking of tunnel wall concrete. The construction method comprises the steps that S1, before wall concrete is poured, prestressed tendons are evenly distributed in a wall; s2, the prestressed tendons are subjected to graded tensioning for m times, m is larger than or equal to 2, the tensioning force of each time of tensioning is 0.15 sigmacon < = 0.5 sigmacon, and sigmacon is tensioning control stress; and S3, wall concrete pouring and curing are conducted, the concrete strength and the shrinkage strain value are monitored during curing, when the concrete strength reaches 30% or above of the design strength and the shrinkage strain value is larger than or equal to 50 mu epsilon, the prestressed tendons are released in a grading mode, and the releasing stress of each grade is smaller than or equal to 0.5 sigmacon. According to the method, cooperative control of graded tensioning and graded releasing is carried out in the wall concrete, so that the concrete keeps reasonable pre-compressive stress in each hardening stage, the tensile stress generated by shrinkage is counteracted, cracks of the wall are avoided, and the structural integrity of the tunnel wall is guaranteed.
Owner:CCCC FOURTH HARBOR ENG CO LTD +1

A device and method for testing the anti-shrinkage cracking toughness of a pavement cementitious material

The application belongs to material evaluation method, and relates to a testing device and method for anti-shrinkage cracking toughness of pavement cementitious material. i and shrinkage deformation data l i of the test specimen at the i-th collection time; and S4, calculating the shrinkage cracking toughness. The shrinkage cracking toughness can truly reflect the mechanical properties of the material, the shrinkage state of the pavement cementitious material is accurately simulated, the accuracy, scientificity and rationality of the test result are improved.
Owner:CCCC FOURTH HIGHWAY ENG CO LTD +1

SAP modified solid waste-based low-carbon concrete and preparation method thereof

The invention discloses SAP modified solid waste based low-carbon concrete and a preparation method thereof.The SAP modified solid waste based low-carbon concrete is prepared from, by weight, 0.5-2.5 parts of solid SAP, 76-146 parts of composite steel slag powder, 25-50 parts of an exciting agent, 60-70 parts of fly ash, 187-212 parts of mineral powder, 187-212 parts of cement, 750-772 parts of machine-made medium sand, 900-930 parts of stone, 9.5-9.81 parts of a high-performance water reducing agent and 135-142 parts of water. A nano SAP suspension; wherein the total weight part of the composite steel slag powder, the mineral powder, the fly ash, the exciting agent and the cement is 560-570, and the exciting agent comprises gypsum and silica fume; sAP is a cross-linked polyacrylic acid and acrylamide copolymer. According to the invention, through the internal curing effect of the SAP, the problem of shrinkage cracking of the large-volume multi-source solid waste concrete is effectively solved, and meanwhile, the SAP is utilized to pretreat the coarse aggregate, so that the aggregate-slurry interface structure is improved, and the volume stability and mechanical properties of the concrete are remarkably improved. According to the method, high-added-value resource utilization of the industrial solid waste is achieved, and remarkable low-carbon and environment-friendly benefits are achieved.
Owner:SHANGHAI CONSTR BUILDING MATERIALS TECH GRP CO LTD

Shrinkage-reducing and crack-reducing mass concrete and method for preparing the same

The application discloses a shrinkage and crack resistance type mass concrete and a preparation method thereof. The shrinkage and crack resistance type mass concrete is composed of cement, fly ash, mineral powder, fine aggregate, coarse aggregate, a high water absorption and release composite shrinkage reducing agent, an additive and water. The high water absorption and release composite shrinkage reducing agent is prepared by the following steps: polymerization of polyethylene glycol ether acrylate, acrylic acid, acrylamide and 2-acrylamide-2-hydroxypropanesulfonic acid through a free radical polymerization reaction, crosslinking reaction of the obtained polymer and a crosslinking agent N, N-methylenebisacrylamide under the action of hydrochloric acid, and neutralization of the obtained polymer after the crosslinking reaction by adding alkali. The mass concrete has the advantages of meeting the mechanical properties and workability, further solving the problems of easy shrinkage and cracking of traditional mass concrete, and wide application prospect.
Owner:CHINA STATE CONSTR READY MIXED CONCRETE CO LTD

A connecting structure of a steel wire mesh skeleton composite pipe

The utility model relates to pipeline connection technical field especially relates to a kind of connecting structure of steel wire mesh skeleton composite pipe, including shell and pipe fitting, the pipe fitting is arranged between two the shell, adjusting mechanism is equipped in the shell, the adjusting mechanism includes fixed block, slide bar, magnetic block, heating sheet, extraction cylinder, two the fixed block is respectively fixedly connected on the inner side wall of the shell, the utility model is cooperated by air bag, extraction cylinder, shell and so on structure, preliminary connection is fixed and sealed using magnetic block, heating sheet is inducted eddy current heating while driving magnetic block reciprocating motion, gas in the shell is rapidly extracted, so that pipe material is not affected by external influence and is heated evenly, reduce the heat damage heating more rapidly, improve the efficiency of cladding, slowly cooling contraction is stable, avoid temperature cooling distribution uneven and local shrinkage cracking caused by rapid cooling due to wind blowing, and connection effect is better.
Owner:SHANDONG BRILLIANT COMM TECH

Basalt fiber reinforced ultra-high performance concrete and preparation process thereof

The application relates to the technical field of building materials, and discloses a basalt fiber reinforced ultra-high performance concrete and a preparation process thereof, which is prepared from basalt fibers, Portland cement, silica fume, quartz sand, a dynamic wetting cross-linking composite liquid, a mesoporous adsorption targeting defoaming carrier and a phase change temperature control solid-liquid phase. In the preparation, the fibers are tumbled at a low speed and are uniformly sprayed and beaten with the composite liquid, the solid powders are sequentially added and dry-mixed, then the solid-liquid phase is added at one time and is high-speed forced mixed, and the concrete is prepared through molding and alternate curing. The composite liquid forms a liquid film on the surface of the fibers and establishes a chemical bond bridge, so that the dispersion state of the fibers and the interfacial bonding strength are improved; the fine ice chips in the solid-liquid phase change and absorb heat, so that the early hydration temperature rise is effectively inhibited, and the risk of shrinkage cracking is reduced; and the defoaming carrier slowly releases the defoaming agent and discharges the internal small bubbles. The application solves the problems of fiber dispersion difficulty and early shrinkage cracking, and improves the compactness of the concrete.
Owner:FUJIAN HUIFENG CONSTR TECH CO LTD

Bi-component nano acrylate grouting plugging material and preparation method thereof

PendingCN121319537APolymer sciencePtru catalyst
The invention discloses a two-component nano acrylate grouting plugging material and a preparation method thereof. The plugging material comprises a component A and a component B, the component A is prepared from the following raw materials in parts by mass: 15 to 25 parts of acrylate monomer, 3 to 8 parts of nano modified filler, 2 to 6 parts of silicon precursor, 0.05 to 0.3 part of cross-linking agent, 8 to 15 parts of tackifier, 0.8 to 2.5 parts of accelerant, 0.1 to 0.5 part of pH regulator and 40 to 60 parts of deionized water; the nano modified filler is pretreated by a coupling agent KH-570; the component B is prepared from the following raw materials in parts by mass: 0.6-2.0 parts of an initiator, 0.02-0.2 part of a composite catalyst, 0.3-1.0 part of a dispersion stabilizer and 95-105 parts of deionized water; the compressive strength of the material is 5.5 to 6.2 MPa; the dry shrinkage rate after 50 times of dry-wet cycles is less than or equal to 2%; after the component A and the component B are mixed, the viscosity is less than or equal to 50mPas, and the component A and the component B can permeate microcracks of 0.1 mm or below; the mass loss rate is less than or equal to 1.4% after soaking in 10% sodium chloride for 30 days; an acute toxicity test shows that LD50 is greater than 5000mg / kg; the preparation method can solve the problems of non-uniform dispersion, low compressive strength of the material, dry shrinkage cracking and poor process stability of the nano filler in the existing preparation technology.
Owner:CHINA RAILWAY 20TH BUREAU GROUP CO LTD +1

Reusable micro-ablation aerogel thermal insulation material and preparation method thereof

The preparation method comprises the following steps: preparing an alumina nanowire ball with a certain length-diameter ratio by adopting a solvothermal method, carrying out high-shear mixing on the alumina nanowire ball, boron phenolic resin, silica sol and chopped fibers to form a multi-stage enhanced network, and carrying out compression molding, curing, subcritical drying and other process steps to obtain the reusable micro-ablation aerogel thermal insulation material. The inorganic-organic hybrid aerogel thermal insulation material with excellent ablation resistance is successfully prepared. Through collaborative optimization of in-situ compounding of organic and inorganic components and subcritical drying, efficient preparation of the aerogel with low cost, ablation resistance and good mechanical strength is realized. The aluminum oxide nanowire clusters and the quartz fibers are introduced as inorganic components, so that shrinkage cracking caused by pyrolysis of the phenolic resin is inhibited, and the structural stability and ablation resistance of the material at high temperature are remarkably improved.
Owner:BEIHANG UNIV

A method of mass concrete construction

The application relates to the technical field of concrete construction, and particularly discloses a mass concrete construction method, which comprises the following steps: S1, preparing low-waterization-heat low-shrinkage high-durability mass concrete; S2, transporting, pouring and vibrating the concrete; when the concrete is poured, a pipe is first moistened by hot water and mortar with a temperature not lower than 15 DEG C before pumping in winter construction, and the concrete pumping pipeline is wrapped with reflective heat preservation materials in summer construction, so that the temperature difference between the inside and outside of the pumping pipeline is between 1-1.5 DEG C; the temperature of the mass concrete when entering a mold in a high-temperature environment in summer is controlled to be less than 30 DEG C, and the temperature of the mass concrete when entering the mold in a cold environment in winter is controlled to be higher than 10 DEG C; and S3, concrete curing; in the concrete curing process, the temperature difference between the center and the surface of the concrete during summer curing is controlled to be not greater than 25 DEG C. The application has the characteristics of reducing the concrete shrinkage and cracking risk.
Owner:CHINA WEST CONSTR GRP +1

A concrete shrinkage and cracking prediction method and system based on multi-dimensional perception data coupling

The application provides a concrete shrinkage and cracking prediction method based on multi-dimensional sensing data coupling, relates to the technical field of concrete shrinkage and cracking prediction methods, and comprises the following steps: a multi-parameter weighted degradation evaluation method is used to calculate the degradation parameters of concrete; a temperature and humidity coupling parameter of concrete is constructed; the autogenous shrinkage strain, the drying shrinkage strain and the temperature shrinkage value of the concrete in a monitoring period are weighted and calculated to obtain the theoretical shrinkage strain value of the concrete in the monitoring period; based on the corrected theoretical shrinkage strain value and the full-cycle crack coefficient, a threshold response method is used to construct a comprehensive risk index, and the comprehensive risk index is classified and early warned. Through time-varying normalization and nonlinear correction, the dynamic interaction between the hydration process and the environmental influence is quantified by synchronously integrating the resistivity, the porosity, the temperature difference and the external environmental data.
Owner:中电建路桥集团有限公司

Cement stabilized macadam with composite shrinkage control and preparation method thereof

The application discloses a cement stabilized macadam for composite regulation of shrinkage, which is prepared from the following raw materials in percentage by weight: cement, water, macadam, steel slag, polyethylene glycol, superabsorbent resin and silica ash. The application also discloses a preparation method, which comprises the following steps: S1, adding the polyethylene glycol into mixing water to be stirred and dispersed into a solution, then adding the steel slag into the solution to be stirred and soaked for a certain time, so as to obtain a steel slag polyethylene glycol mixture for standby; S2, adding the superabsorbent resin into mixing water to be stirred while adding the superabsorbent resin, so as to obtain a superabsorbent resin gel for standby; S3, mixing and stirring the steel slag polyethylene glycol mixture, the superabsorbent resin gel and the macadam, adding the cement and the silica ash to be stirred, and finally adding the remaining water to be stirred, so as to obtain the cement stabilized macadam for composite regulation of shrinkage. The cement stabilized macadam can be regulated from temperature shrinkage and dry shrinkage to control the shrinkage deformation, so as to inhibit the formation and development of the shrinkage cracking of the cement stabilized macadam and improve the service performance of the road surface quality.
Owner:GUANGXI TRANSPORTATION SCI & TECH GRP CO LTD +1

Concrete shrinkage cracking prediction method and system based on multi-dimensional perception data coupling

The invention provides a concrete shrinkage cracking prediction method based on multi-dimensional perception data coupling, and relates to the technical field of concrete shrinkage cracking prediction methods, and the method comprises the steps: employing a multi-parameter weighted degradation evaluation method to calculate concrete degradation parameters; constructing temperature and humidity coupling parameters of the concrete, and performing weighted calculation on the authigenic shrinkage strain, the drying shrinkage strain and the temperature shrinkage value of the concrete in the monitoring period to obtain a theoretical shrinkage strain value of the concrete in the monitoring period; and on the basis of the corrected theoretical shrinkage strain value and the complete-period crack coefficient, constructing a comprehensive risk index by adopting a threshold response method, and carrying out classified early warning on the comprehensive risk index. The resistivity, the porosity, the temperature difference and the external environment data are synchronously integrated, and the dynamic interaction between the hydration process and the environment influence is quantified through a time-varying normalization method and a nonlinear correction method.
Owner:中电建路桥集团有限公司