Concrete and sand that were replaced by coal bottom ash concrete were analyzed and compared for strength and heat conductivity. Thermal conductivity was measured using an instrument, based on the Transient Plane Source technique. When the samples contained 40% replacement coal, the thermal conductivity value was reduced by 35%, for 60% replacement the thermal conductivity value was reduced by 36.5%, and for 100% replacement, thermal conductivity was reduced further to around 51%....