Development of PCM-enhanced mortars for thermally activated building components

Low energy strategies are being increasingly studied to improve the efficiency of the built environment ensuring thermal comfort conditions. The combined use of Thermal Energy Storage (TES) systems and Thermally Activated Building Systems (TABS) has a great energy saving potential, allowing an efficient integration and management of renewable energy sources in buildings. This study describes the experimental campaign carried out to characterise different Phase Change Material (PCM)-based mortars and slurries for incorporation in precast building components actively controlled by means of an integrated hydronic radiant system. Specifically, this work focuses on the effects of the direct incorporation of different amounts of microencapsulated PCM on fresh and hardened material properties, such as workability, thermal conductivity and density. Results show that increasing PCM amounts significantly reduces the workability of the mixtures, leading to the use of high water-to-cement ratios. Regarding the properties in hardened state, increasing the PCM dosage increases the latent heat storage capacity, but both thermal conductivity and density drastically decrease, reducing the thermal effusivity of the mixture. These aspects highlight the importance of a fine-tuned formulation of the PCM-enhanced material in order to achieve high-performing building elements.