thermal conductivity of concrete increases with increasing moisture content. Since water has a conductivity about 25 times that of air, it is clear that when the air in the pores has been partially displaced by water or moisture, the concrete must have greater conductivity [1,6-9]. Steiger and Hurd [10] reported that, when unit weight of concrete increased 1% due to the water absorption, the thermal conductivity of these specimens increases 5%