Preparation and construction method of composite admixture, compounding method and coal mine outer shaft wall concrete

Abstract

Relating to freezing shaft sinking technologies, the invention relates to a composite admixture, a compounding method and a construction method for coal mine outer well wall concrete, and can solve the early strength problem of concrete. The composite admixture includes: a mineral additive accounting for 98-99% of the total mass and a coagulating type water reducer. The mineral additive includes at least one of metakaolin, silica fume, and mineral powder. When the shrinkage type water reducer is in a solid state, the shrinkage type water reducer accounts for 1-2% of the total mass, and when the shrinkage type water reducer is in a liquid state, the loss solid mass of the shrinkage type water reducer accounts for 1-2%. After the composite admixture provided by the invention is blended into concrete, the mineral additive can provide early strength, workability and stability of concrete. The coagulating type water reducer can promote the early hydration rate of cement's main mineral components in concrete, participate in hydration reaction, fill the pore structure, and accelerate the concrete hydration coagulation, thereby realizing the early strength of concrete.

Description

Technical field [0001] The invention relates to a freezing shaft sinking technology, in particular to a method for preparing and constructing a composite admixture, a compounding method, and the outer shaft wall concrete of a coal mine. Background technique [0002] Frozen shaft sinking is widely used in coal mining and production. Frozen shaft sinking is a method of artificial refrigeration. Frozen pipes are drilled around the well to cool and freeze the soil around the frozen pipe. As the frozen soil expands, a temporary shaft wall with frozen soil is formed. The strength is high and it can isolate the water source. Under the protection of the temporary shaft wall, the excavation, construction and production of the shaft soil can be carried out. [0003] In the process of freezing the outer shaft wall, the concrete is usually made of cement, sand, gravel, admixture and water in a certain proportion. The existing concrete has a long setting time, which will seriously restrict the...

AI Technical Summary

Problems solved by technology

In order to make the concrete produce early strength, the early strength agent of inorganic salts will be added to the concrete, but this will lead to a decrease in the strength of the concrete in the later stage and reduce the reliability of the concrete

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