Moisture content influence on thermal conductivity of concrete

Abstract

In this paper, physical processes of adsorption and transport of humidity, which has dominant influence on the physical and thermal characteristics of concrete, has been described. The impact of structure of concrete especially pores dimensions and distribution has been explained. The drastic increase in the coefficient of thermal conductivity λ of concrete at increasing relative humidity has been analyzed. An analytic formula for λ, as a function of the concrete density and moisture content in exploitation conditions, starting from light autoclaved aerated to heavy concrete, has been given. The formula is based on experimental values for λ available in the literature. It has been confirmed that the thermal conductivity of all concretes are directly related to density and inversely to porosity and pores diameters.