Revisiting the block method for evaluating thermal conductivities of clay and granite

Determination of thermal conductivities of porous media using the contact method was revisited and revalidated. Thermal conductivities of granite and clay were determined in the laboratory with and without the use of thermal interface material (TIM) (Arctic Silver®) to reduce contact resistance. KD2 probe was also used with and without TIM to compare results. Thermal conductivity of dry clay sample increased from 0.68 W/mK to 0.85 W/mK while that of granite sample increased from 2.95 W/mK to 3.95 W/mK with TIM. The difference in thermal conductivities with and without TIM was significant at (P > 0.05).