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An experimental study on the viscosity features of sealant (bentonite-cement slurry) in umbrella arch method

강관다단공법에 적용되는 씰링재 (벤토나이트-시멘트 슬러리)의 점성 특성에 대한 실험

  • 사공명 (한국철도기술연구원 첨단궤도토목연구본부) ;
  • 이준석 (한국철도기술연구원 첨단궤도토목연구본부) ;
  • 박정준 (한국철도기술연구원 첨단궤도토목연구본부) ;
  • 조충식 (지오텍엔지니어링(주) 설계팀)
  • Received : 2018.06.14
  • Accepted : 2018.07.19
  • Published : 2018.09.30

Abstract

In this paper, viscosity features of sealant (bentonite-cement slurry), which is used for umbrella arch method in tunnel, were studied. The sealant must secure optimal strength and capacity for the waterproof and stabilization of borehole as well as to satisfy groutability. In this study, the variation of viscosity was measured with different mixing processes. With an increase of initial mixing period with water and bentonite mixture, the required time for the rapid increase of viscosity of the sealant is shorten. With increase of mixing period, the possibility of swelling of bentonite will increases and this can lead increase of the viscosity of the mixture. In addition, the behaviors of sealant vary with a drastic increase of the viscosity: thixotropy and rheopexy. Furthermore, the bentonite/water mixing period influences on the bleeding features of the sealant. Further study is required to introduce the guideline, which can be applicable in the field in the aspect of required capacity of the sealants and mixing processes of the ingredients.

Acknowledgement

Supported by : 한국철도기술연구원

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