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Thixotropic shield backfill grouting slurry

A post-wall grouting and thixotropic technology, applied in the field of thixotropic slurries, can solve the problems of difficult management, high cost, easy to block pipes, etc., and achieve the effect of good fluidity and good thixotropy

Inactive Publication Date: 2012-10-17
HOHAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, this method has the disadvantages of difficult management and high cost during construction, especially because the initial setting time of the double liquid slurry is too fast, and pipe plugging is prone to occur during the pumping process.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Each component of the present invention is mixed uniformly by following percentage by weight:

[0019] Cementitious material 24.3%

[0020] Bentonite 2.8%

[0021] Sand 53.9%

[0022] Water 18.6%

[0023] Water reducer 0.38%

[0024] Positive gel 0.02%,

[0025] The above-mentioned cementitious material is composed of cement and fly ash, and the weight ratio between them is cement: fly ash=1:3.

[0026] The flow yield strength of the slurry mixed according to this ratio can reach 900Pa after standing for two hours, and after 30 seconds of stirring, the flow yield strength drops to 150Pa, and the strength of the stirred slurry returns to 800Pa after 20 minutes above. The utility model can meet the requirement that the grout does not block the pipe and not flow along the shield shell during construction, and the grout cost is low.

Embodiment 2

[0028] Each component of the present invention is mixed uniformly by following percentage by weight:

[0029] Cementitious material 24.3%

[0030] Bentonite 2.3%

[0031] Sand 53.9%

[0032] Water 18.6%

[0033] Water reducer 0.4%

[0034] Magnesium Aluminum Silicate Mineral Gel 0.5%,

[0035] The above-mentioned cementitious material is composed of cement and fly ash, and the weight ratio between them is cement: fly ash=1:3.

[0036] The flow yield strength of the slurry mixed according to this ratio can reach 750Pa after standing for two hours, and after 30 seconds of stirring, the flow yield strength drops to 100Pa, and the strength of the stirred slurry returns to 650Pa after 20 minutes above. It can meet the requirements that the slurry will not block the pipe and not flow along the shield shell during construction. And the slurry is cheap to manufacture.

Embodiment 3

[0038] Each component of the present invention is mixed uniformly by following percentage by weight:

[0039] Cementitious material 24.3%

[0040] Bentonite 2.3%

[0041] Sand 53.9%

[0042] Water 18.6%

[0043] Water reducer 0.4%

[0044] Magnesium Aluminum Silicate Mineral Gel 0.48%

[0045] Positive gel 0.02%,

[0046] The above-mentioned cementitious material is composed of cement and fly ash, and the weight ratio between them is cement: fly ash=1:3.

[0047] The flow yield strength of the slurry mixed according to this ratio can reach 1050Pa after standing for two hours, and after 30 seconds of stirring, the flow yield strength drops to 150Pa, and the strength of the stirred slurry returns to 900Pa after 20 minutes above. It can meet the requirements that the slurry will not block the pipe and not flow along the shield shell during construction. And the slurry is cheap to manufacture.

[0048] The mechanism of thixotropy in the grouting slurry behind the shield w...

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PUM

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Abstract

The invention discloses a thixotropic shield backfill grouting slurry, comprising the following components by weight percentage: 16-30% of cementitious material, 1.8-3.6% of bentonite, 50-65% of sand, 17-22% of water, 0.19-0.50% of water reducer, and 0.01-0.50% of thixotropic lubricant. The thixotropic shield backfill grouting slurry has better thixotropy; after being grouted into a shield tail gap, the flow yield strength of the slurry is large enough and the slurry hardly flows; however, under the condition of high-speed flowing or stirring, the slurry has excellent flowability, thereby avoiding pipe blockage.

Description

[0001] technical field [0002] The invention belongs to the technical field of new material development for underground engineering, and mainly relates to a thixotropic slurry used for filling gaps in shield tails of shield machines. Background technique [0003] At present, the method used to fill the shield tail gap in shield tunneling construction in China is behind-the-wall grouting technology. During construction, the grout mixed on site is pumped into the shield tail gap. In the current shield tunnel construction, rigid single-liquid slurry is generally used, and its main components are cement, fly ash, bentonite, sand, water, and water reducing agent. This kind of slurry has the characteristics of high strength and low cost after consolidation and hardening, and has played a good role in the construction of shield tunnels in soft soil strata in China. In order to meet the construction requirements, the initial fluidity of the slurry is usually relatively large. So...

Claims

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Application Information

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IPC IPC(8): C04B28/00
Inventor 钟小春赵赫覃炜珂汪海赵静王慧洁
Owner HOHAI UNIV