1. Federal Highway Administration Highway Statistics Publications, Highway Finance Tables SF-4C and LGF-2, 1997-2005;FHWA,2006
2. A. International Ground Source Heat Pump, I. Electric Power Research, and A. National Rural Electric Cooperative, Grouting for Vertical Geothermal Heat Pump Systems: Engineering Design and Field Procedures Manual;Hiller,2000
3. Characteristics of thermally-enhanced bentonite grouts for geothermal heat exchanger in South Korea;Lee;Sci. China E Tech. Sci.,2010
4. Enhancement of geothermal borehole heat exchangers performances by improvement of bentonite grouts conductivity;Delaleux;Appl. Therm. Eng.,2012
5. Relationship between thermal conductivity and soil–water characteristic curve of pure bentonite-based grout;Kim;Int. J. Heat Mass Tran.,2015