Free cutting concrete

Abstract

The invention relates to an easy-cutting concrete, which is composed of 10-20% of the total weight of cementitious material, 28-35% of yellow sand, 40-45% of dolomite and the rest of water and additives, wherein the added The water: the weight ratio of cementitious material is 0.4~0.45, and admixture is 0.8~1.0% of gel material weight, and described cementitious material is the mixture of cement and fly ash, and the particle diameter of dolomite is 5~1.0%. 16mm. The free-cutting concrete of the present invention adopts the dolomite component that is not commonly used in the prior art, and the proportion of this component is specially adjusted, and the obtained free-cutting concrete can not only meet the construction of the ultra-deep underground diaphragm wall concrete Performance indicators such as high impermeability, high crack resistance and low shrinkage can also meet the machinability of long-term (more than 3 years) shield tunneling, forming a complete set of machinable concrete technology in the field of ultra-deep tunnels, making up for domestic and foreign research and development. Apply blank.

Description

technical field [0001] The invention relates to concrete, in particular to an easy-cutting concrete. Background technique [0002] With the rapid development of urban construction, tunnel projects including tunnels, subways, and deep storage pipelines have entered a stage of extraordinary development. In order to avoid urban traffic operations as much as possible, shield tunneling is often used for construction of such tunnel projects. Shield tunneling construction is a highly mechanized and automated tunneling construction method, which has high technical and economic advantages. It is extremely difficult for the excavating tool of the shield machine to directly excavate and break the concrete of the portal, and directly cutting the concrete will cause damage to the excavating tool of the shield machine, which has become a major problem in tunnel construction. Many scholars have done in-depth research on the technical measures of shield cutting concrete, but most of them f...

AI Technical Summary

Problems solved by technology

At present, when shields enter and exit the tunnel, underpinning, chiseling, and pulling out are often used. There are very few cases of directly passing through the diaphragm wall, and there is no precedent in the ultra-deep tunnel project. If the construction of the ultra-deep diaphragm wall can meet the Under the premise of performance indicators such as high impermeability, high anti-permeability, high crack resistance and low shrinkage, the development of long-term machinable concrete will be of great significance for speeding up construction, saving engineering investment, and shortening the construction period.

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