9results about How to "Rapid early strength development" patented technology

The application discloses a kind of high density low rebound shotcrete and preparation method thereof, it is related to shotcrete field, and preparation method includes: (1), respectively to cementitious material, fine aggregate, coarse aggregate is using MAA model to be packed and the design ratio of each raw material in interior is obtained;(2), cementitious material, fine aggregate, coarse aggregate and the rebounding agent of design ratio obtained according to step (1) are fully mixed, water, water reducing agent is mixed, then by the way of mixing with pressurized air, incorporate accelerator, obtain high density low rebound shotcrete.The application uses early strength rebounding agent, improves the pumpability of shotcrete, accelerates the early hydration of concrete, under the joint action of alkali-free accelerator, rapidly improves the early mechanical properties of shotcrete, improves shotcrete construction efficiency.Multiple close packing is used, and cementitious material, fine aggregate, coarse aggregate respectively form close packing structure, effectively improve the plastic viscosity of paste and the compactness of concrete.

The application discloses a shotcrete rebound-reducing agent and a preparation method thereof. The shotcrete rebound-reducing agent is prepared from the following raw materials in mass percentage: 15-30% of a quick-setting component, 2-5% of a viscosity-increasing component, 10-15% of a reinforcing component, 2-5% of an anti-freezing component, 1-4% of a stabilizer, and the rest of water; and the viscosity-increasing component is a combination of polyvinylpyrrolidone and modified carboxymethyl cellulose. The prepared shotcrete rebound-reducing agent has the advantages of good sprayability, high hourly strength, good anti-freezing and stability, and the like, can improve the working performance of shotcrete, reduce the content of a quick-setting agent and significantly reduce the rebound rate of shotcrete, and has good economic benefits.

This invention discloses a method for repairing asphalt pavement through pipeline excavation, comprising the following steps: S1: Milling and crushing the original road structure in layers to produce old asphalt pavement waste and old base course waste; S2: Excavating a trench downwards from the top surface of the original roadbed, laying a pipeline, and filling the trench to the top surface of the original roadbed; S3: Processing the old base course waste to form recycled aggregate, and then mixing it to form self-compacting concrete; S4: Forming a self-compacting recycled concrete base course above the backfill material; S5: Crushing and screening the old asphalt pavement waste into a first waste with a small particle size and a second waste with a large particle size; S6: Heating the first waste, adding the first aggregate, adding asphalt and a recycling agent, and mixing to form a medium-grained recycled asphalt mixture, forming a recycled medium-grained asphalt concrete surface layer; S7: Heating the second waste, adding the second aggregate, adding asphalt and a recycling agent, and mixing to form a fine-grained recycled asphalt mixture, forming a recycled fine-grained asphalt concrete surface layer, thus completing the pavement repair.

This invention discloses a phosphorus slag-based cementitious material, its preparation method, and its application, specifically relating to the field of cementitious materials technology. The cementitious material, by weight, comprises the following components: 60-90 parts phosphorus slag powder; 5-25 parts fly ash; 5-15 parts activator; 0.25-1.5 parts early-strength agent; and 0.2-0.5 parts water-reducing agent; wherein the specific surface area of ​​the phosphorus slag powder is 400-550 m². 2 / kg, particle size (D) 90 The particle size is 20-40 μm; the early-strength agent is selected from at least one of iron salts and aluminum salts. This invention uses phosphorus slag micro-powder with a specific specific surface area as the main substrate, with a high dosage, combined with fly ash, activator, early-strength agent, and water-reducing agent to obtain phosphorus slag-based cementitious materials. By optimizing the physical properties of the phosphorus slag micro-powder and constructing a suitable composite activator-early-strength system, the 28-day compressive strength of the cementitious material reaches over 61.0 MPa, achieving a balance between "high phosphorus slag content" and "high strength".

The application discloses a controllable water-permeable solidified grouting material and a preparation method and application thereof, belongs to the technical field of geotechnical engineering foundation reinforcement and underground cavity filling, and aims to solve the technical problem that existing grouting materials are difficult to keep a certain solidified strength and accurately control the water permeability coefficient according to geological requirements to adapt to different hydrogeological environments. The controllable water-permeable solidified grouting material comprises, in weight parts, 45-55 parts of a main solidified base material, 8-18 parts of a water-permeable control system, and 25-35 parts of deionized water. The water-permeable control system comprises porous volcanic rock powder, lignin fiber and modified bentonite, and the mass ratio of the porous volcanic rock powder, the lignin fiber and the modified bentonite is 50:35:15. The porosity of the porous volcanic rock powder is 45%-55%, the length of the lignin fiber is 3 mm-6 mm, and the expansion rate of the modified bentonite is 150%-280%.

The present application relates to the technical field of sludge solidifying agent, and discloses a preparation method of a composite ternary system sludge solidifying agent, which comprises the following steps: placing ternary cementing material, mineral powder and slag reducing agent in a stirrer to stir and form A material; mixing polyacrylate emulsion, styrene-acrylic emulsion and water to stir and form B material; and respectively placing A material and B material in the stirrer to stir and form the composite ternary system sludge solidifying agent. The ternary cementing material is respectively silicate cement, sulphoaluminate cement and gypsum, which can cause ternary system solidification, reinforce and densify the cement stone structure, ensure the growth of the late strength of cement, cause mineral powder and alkali slag to be solidified by mineral powder slag reduction, strengthen the whole solidification system and make the late strength develop well, and the solidified sludge has the characteristics of extremely fast early strength development, good water stability and high late strength by mixing polyacrylate emulsion and styrene-acrylic emulsion polymer materials to improve the soil performance.

This invention discloses a mine backfill cementitious material and its preparation method. The mine backfill cementitious material of this invention comprises the following components in the following mass ratios: high belite sulfoaluminate cement clinker: 3-8 wt%; high free calcium silicate cement clinker: 1-3 wt%; granulated blast furnace slag powder or granulated blast furnace slag: 74-85 wt%; gypsum: 10-18 wt%. Compared with other paste-like backfill materials of the same strength, the cementitious material of this invention solves the problems of poor activation effect, poor mechanical properties affecting the mine backfilling effect, and high cost due to large amount of cementitious material used in existing mine backfill cementitious materials. At the same time, it not only reduces the proportion of cementitious material used, but also fully meets the requirements of mine backfilling projects.

The present application relates to the field of subgrade soil treatment, and particularly relates to a subgrade in-situ soil high-performance ecological enhancer, a preparation method and a construction method, the enhancer comprising the following raw materials in percentage by mass: sulphoaluminate cement 45-85%; Portland cement 8-25%; quicklime 3-5%; fly ash 0-15%; silica fume 0-8%; slag powder 0-15%; sodium sulfate 3-5%; sodium silicate 0-2%; lithium carbonate 0-0.8%; polymer enhancer 0-1.5%; silicone powder 0-1.5%; sodium lignosulfonate 0.1-0.3%. The enhancer effectively combines the advantages of sulphoaluminate cement and Portland cement, combines other components, has the characteristics of rapid setting and fast early strength development, can regulate soil strength, meets the requirements of compressive strength and durability in engineering construction, shortens the construction period, and meets the demand of 4-6h rapid traffic under the scene of emergency repair.

This invention provides a low-shrinkage, crack-resistant, ultra-high performance concrete composition, its preparation process, and its application. The concrete composition includes cement, fly ash, silica fume, quartz sand, CaO expanding agent, MgO expanding agent, pre-absorbent zeolite powder, polycarboxylate superplasticizer, steel fiber, and water. This invention employs a composite expansion source of calcium oxide and magnesium oxide, synergistically combined with a pre-absorbent zeolite powder internal curing agent, to achieve full-process shrinkage compensation from early to late stages. A progressive curing system of "initial film sealing – steam curing with mold – later water retention" is designed, and segmented skip-construction and induced joint construction methods are provided for large-area components. Through precise matching of material temporal compensation and external curing, the system systematically stimulates shrinkage potential, achieving three-dimensional crack suppression throughout the entire process while ensuring the ultra-high strength of UHPC, ultimately obtaining crack-free components with high dimensional stability. This is particularly suitable for projects with extremely high crack resistance requirements, such as large-volume, ultra-long structures.