Novel Cement-Lime Composites with Phase Change Materials (PCM) and Biomass Ash for Energy Efficiency in Architectural Applications

Abstract

The improvement of energy efficiency in buildings is the goal of many new European standards and regulations. New building technologies and materials are being designed to achieve this goal by integrating new properties through new dynamic environment responsive and recycled components. In this study, lime cement pastes with phase change materials (PCM), due to their thermal storage capacity, and biomass ashes, because of their good mechanical and physical behavior, were investigated. An experimental program was carried out to assess the synergies and effects of the biomass ashes and PCM on the mineralogical, physical, mechanical and thermal performance of the mixtures. Nine cement-lime pastes were designed, where 10 and 20% cement was replaced by biomass ashes and 10% and 20% of microencapsulated paraffin waxes PCM were incorporated. Bulk density, open porosity, capillary water absorption, compressive and flexural strength, Ultrasonic Young Modulus and thermal conductivity were characterized. It was found that biomass ashes did not modify significantly the mixtures properties while increased material’s sustainability. On the hand, PCM changed the physical, mechanical, and thermal properties of the mixtures that can be advantageous for building applications as mortar renders. The larger the PCM addition, the higher the mixtures properties changes.