3results 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.

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.

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.