Thermal conductivity of Geosynthetic Clay Liners

The thermal conductivities of powdered and granular bentonite based needle punched GCLs were investigated at different gravimetric water contents under 25, 50, 75 and 100 kPa vertical stresses, respectively. Both types of GCLs exhibited an increase in thermal conductivity with increasing vertical stress at all water contents. The effect of vertical stresses was more pronounced for the specimens hydrated at lower gravimetricwater contents and this was attributed to their high initial volumetric air content. The variability of water distribution in partially hydrated GCLs has been identified as a factor which may affect their thermal conductivity. The forms of bentonites (i.e., powder or granular) affected their thermal conductivities; however, this effect was less apparent at higher gravimetric water contents due to the reduced air content and gel formation in the bentonites. Finally, the GCL thermal conductivity, calculated from the measured thermal conductivities of its various constituents (i.e geotextile and bentonite) components, differed from the measured values. This was attributed to the non-uniform water distribution across the GCL specimen and change in material properties when components of GCL were disassembled.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author