Experimental Investigation of Thermal Conductivity of Concrete Containing Micro-Encapsulated Phase Change Materials

The aim of increasing the building internal heat storage capacity is to be able to store excessive heat gains and by that reduce indoor high temperature peaks and at the same time shift high heat loads to the low heat loads hours and to decrease cooling energy need. The concept presented in this article utilizes integration of the concrete and the microencapsulated Phase Change Material (PCM). PCM has the ability to absorb and release significant amounts of heat at a specific temperature range. As a consequence of admixing PCM to the concrete, new thermal properties like thermal conductivity and specific heat capacity have to be defined. This paper presents results from the measurements of the thermal conductivity of various microencapsulated PCM-concrete and PCM-cement-paste mixes. It was discovered that increase of the amount of PCM decreases the thermal conductivity of the concrete PCM mixture. Finally, a theoretical calculation methodology of thermal conductivity for PCM-concrete mixes is developed.