Profound freezing well wall high-strength high-performance concrete

Abstract

The present invention discloses a concrete with high strength and high performance for deeply and thickly frozen well wall. The double-doping technology of milled slag as the main mineral doping and different chemical doping is used; the invention is prepared after optimized combination and blending of mixture. The concrete is made by mixing P.0.42.5cement, machine-made sand, limestone rubble, milled rubble, I-level powder coal ash, TK-M intensifier, J851-D early strengthening high-early-strength water reducing agent, JQ-D anti-crack intensifying agent, high-efficiency water reducing agent of liquid polycarboxylic salt, and water. The present invention has the characteristics of the low preparation cost, the simple operation process, the applicability to engineering of the inside of a deeply and thickly frozen and a well wall on the outer layer, and so on.

Description

Technical field: [0001] The invention belongs to the technical field of shaft sinking concrete shaft wall by freezing method of deep and thick alluvial layer in mine vertical shaft. Background technique: [0002] Sinking by freezing method is the main special construction method for shafts passing through deep alluvium at home and abroad. In China, more than 500 mine shafts have been built or are under construction using the freezing method. Before 2000, the maximum thickness of the shafts passing through the alluvial layer was 383m. With the increase of coal demand, the development intensity of coal resources buried under the deep alluvial layer is gradually The thickness of the new well passing through the alluvium has exceeded 500m. As the thickness of the alluvial layer increases, the freezing pressure, water pressure, and ground pressure also increase, which puts forward higher requirements for the strength and performance of the shaft wall concrete. The existing high...

AI Technical Summary

Problems solved by technology

The materials used can make the concrete reach the high grade of C70, but there are still shortcomings. The domestic production of silica fume is small, and the price is dozens of times that of cement. The cost of replacing cement with silica fume is high; high-grade cement, high-quality sand and stone are difficult Local materials are used, and the cost of concrete preparation is high; the viscosity of silica fume concrete is high, the mixing time is prolonged, and the construction techniques such as pouring, tamping, surface smoothing, and maintenance are relatively complicated

The concrete prepared by the general method has low early strength, and the well wall is easy to be crushed; the cement grade is high, the dosage is large, and the heat of hydration is as high as 75-80°C, the inner well wall is prone to temperature cracks, and the well wall leaks after thawing