A ready-mixed synchronous grouting material for shield tunneling construction with high water retention

Abstract

The invention discloses a high-water-retaining-property shield construction premixed synchronous grout material which comprises cement, coal ash, admixture, bentonite, fine sand, additives and water. The additives mainly comprise non-ionic cellulose ether, carbohydrate, polycarboxylic acid slump retaining agents, starch ether and magnetic hydrotalcite. The high-water-retaining-property shield construction premixed synchronous grout material has the advantages that the optimized admixture, the bentonite, the fine sand with the fineness modulus being 1.6 and the additives special for mortar are jointly used in the shield construction premixed synchronous grout material, the fluidity loss of the adjusted grout material is less than or equal to 30mm in 6 hours, bleeding rate is reduced to be lower than or equal to 3.0%, and sedimentation after a vibration test is less than or equal to 20mm; due to the fact that the magnetic hydrotalcite is added, the grout material can reduce construction noise during stirring and absorb heavy metal ions to prevent heavy metal in the mortar from causing secondary pollution on the basis that the original physical properties are kept.

Description

technical field [0001] The invention relates to the field of shield tunneling construction, and mainly relates to a ready-mixed synchronous grouting material for shield tunneling construction with high water retention. [0002] technical background [0003] In the 21st century, the rapid development of China's economy has accelerated the construction of urbanization. With the increase of urban density and the increasing number of high-rise buildings, the available space on the surface is getting less and less. The effective use and development of underground space has become the best choice, and the use of shield method to excavate underground space has been used on a large scale, especially in subway projects. [0004] During shield construction, the diameter of the inner wall of the shield shell is larger than the outer diameter of the segment lining, so as to facilitate the installation of the lining and the construction of the shield curve; the cutting diameter of the sh...

AI Technical Summary

Problems solved by technology

[0005] At present, subways are being built in many places across the country. On-site mixing is generally used for synchronous grouting in shield construction. There are many problems in on-site mixing, such as unprofessional operators, inaccurate measurement, uncontrollable mortar quality, and segregation and stratification; in urban areas The construction of grouting mixing stations on busy roads hinders traffic; raw materials are piled up in the open air and powder materials are used to cause dust, which is not conducive to the establishment of a civilized construction site; there are many management links, and the input and output are out of proportion