Composite admixture, compounding method and construction method for coal mine outer well 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 well-sinking technology by a freezing method, in particular to a composite admixture, a compounding method and a construction method for the concrete of the outer shaft wall of a coal mine. Background technique [0002] Freezing method sinking is widely used in the mining and production of coal mines. The freezing method is to use artificial refrigeration to drill a frozen pipe around the well, and cool down the soil around the frozen pipe to freeze. With the expansion of the frozen soil, a temporary well wall of the frozen soil is formed. The temporary well wall The strength is high, and it can play the role of isolating the water source. Under the protection of the temporary well wall, the excavation, construction and production operations of the wellbore soil can be carried out. [0003] During the freezing method construction of the outer shaft wall, concrete is usually prepared in a certain proportion by cement, sand, g...

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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