Factors affecting the thermal properties of concrete and applicability of its prediction models

In this paper an investigation on thermal conductivity of mortar, concrete and its major constituent aggregate is presented. Four different types of rocks were tested for their conductivities at dry and fully saturated states, which were further crushed and used as coarse aggregates in concrete. Thermal conductivity of mortar and concrete have been measured at various moisture contents. The applicability of Campbell-Allen and Theme's model in assessing the influence of aggregate type has been investigated. Using a few advanced models for thermal conductivity of porous material, it has been demonstrated that there exists a possibility to gain insight into the nature of the pore that is likely to be encountered in the concrete. The relationship between concrete conductivity and aggregate conductivity at various degrees of saturation including at dry and fully saturated conditions have been developed. Further, equivalent conductivity of solid, which is a necessary input parameter for porous material models, has been evaluated for all the types of concrete under consideration. (C) 2002 Elsevier Science Ltd. All rights reserved.