  Thermal conductivity of compacted bentonite is one of the most important
properties in the design of high-level radioactive waste repositories where
this material is proposed for use as a buffer. In the work described here, a
thermal probe based on the hot wire method was used to measure the thermal
conductivity of compacted bentonite specimens. The experimental results were
analyzed to observe the effects of various factors (i.e. dry density, water
content, hysteresis, degree of saturation and volumetric fraction of soil
constituents) on the thermal conductivity. A linear correlation was proposed to
predict the thermal conductivity of compacted bentonite based on experimentally
observed relationship between the volumetric fraction of air and the thermal
conductivity. The relevance of this correlation was finally analyzed together
with others existing methods using experimental data on several compacted
bentonites.
