TY - JOUR
T1 - Viscosity and salinity effect on thermal performance of bentonite-based grouts for ground heat exchanger
AU - Lee, Chulho
AU - Park, Sangwoo
AU - Lee, Dongseop
AU - Lee, In Mo
AU - Choi, Hangseok
N1 - Funding Information:
This research was supported by the Korea Agency for Infrastructure Technology Advancement under the Ministry of Land, Infrastructure and Transport of the Korean government (No. 13 Construction Research T01) and by a grant from the Strategic Research Project (Development of Key Excavation Solutions for Expandable Urban Underground Space) funded by Korea Institute of Civil Engineering and Building Technology .
Publisher Copyright:
© 2014 Elsevier B.V.
PY - 2014/11/1
Y1 - 2014/11/1
N2 - Due to its high swelling potential and low hydraulic conductivity, the bentonite-based grout has been popularly used to backfill a borehole constructed for a closed-loop vertical ground heat exchanger in a geothermal heat pump system. In this study, three types of bentonites were compared in terms of viscosity and thermal conductivity. With the consideration of the groundwater inflow, the viscosity and thermal conductivity of the bentonite grouts having bentonite contents of 5%, 10%, 15%, 20% and 25% by weight were also examined. To evaluate the effect of salinity in the coastal area on the swelling potential of the bentonite, volume reduction tests were performed. And in order to reproduce the particle segregation of bentonite-sand mixture when the bentonite-based grout has relatively low viscosity, the segregation was observed using a ring-type separable test apparatus.
AB - Due to its high swelling potential and low hydraulic conductivity, the bentonite-based grout has been popularly used to backfill a borehole constructed for a closed-loop vertical ground heat exchanger in a geothermal heat pump system. In this study, three types of bentonites were compared in terms of viscosity and thermal conductivity. With the consideration of the groundwater inflow, the viscosity and thermal conductivity of the bentonite grouts having bentonite contents of 5%, 10%, 15%, 20% and 25% by weight were also examined. To evaluate the effect of salinity in the coastal area on the swelling potential of the bentonite, volume reduction tests were performed. And in order to reproduce the particle segregation of bentonite-sand mixture when the bentonite-based grout has relatively low viscosity, the segregation was observed using a ring-type separable test apparatus.
KW - Bentonite
KW - Ground heat exchanger
KW - Salinity
KW - Segregation
KW - Thermal conductivity
UR - http://www.scopus.com/inward/record.url?scp=84908206603&partnerID=8YFLogxK
U2 - 10.1016/j.clay.2014.09.008
DO - 10.1016/j.clay.2014.09.008
M3 - Article
AN - SCOPUS:84908206603
SN - 0169-1317
VL - 101
SP - 455
EP - 460
JO - Applied Clay Science
JF - Applied Clay Science
ER -