Experimental Study on Thermal Conductivity and Viscosity of Grouts for Backfilling Ground Heat Exchanger

수직 밀폐형 자중 열교환기용 뒤채움재의 열전도 및 점도특성 연구

  • 최항석 (고려대학교 건축사회환경공학과) ;
  • 이철호 (고려대학교 건축사회환경공학과) ;
  • 길후정 (고려대학교 건축사회환경공학과) ;
  • 최효범 (㈜건화 기술연구소) ;
  • 우상백 (대원토질㈜ 기술연구소)
  • Published : 2007.12.21


In order to characterize the thermal conductivity and viscosity of grout materials used for backfilling ground heat exchangers, nine bentonite grouts and cement grouts being adapted in the United State have been considered in this study. The bentonite grouts indicate that the thermal conductivity and viscosity increase with the content of bentonite or filler (silica sand). In addition, material segregation can be observed when the viscosity of grout is relatively low. The saturated cement grouts appear to possess much higher thermal conductivity than the saturated bentonite grouts, and the reduction of thermal conductivity in the cement grouts after drying specimens is less than the case of the bentonite grouts. Maintaining the moisture content of grouts is a crucial factor in enhancing the efficiency of ground heat exchangers.