Impact of microencapsulated phase change material on a bio-based building composite, hygrothermal and mechanical behavior

Among the promising solutions to reduce the ecological impact of construction materials is the promotion and development of local natural materials, such as the valorization of agricultural by-products. These bio-based materials offer interesting thermal and acoustic characteristics while significantly reducing the consumption of fossil energy (grey energy) and greenhouse gas emissions associated with their manufacturing process. Moreover, due to their permeable nature, these materials ensure stable hygrothermal exchanges with the surrounding environment. This work aims to develop a new bio-based composite thermally reinforced by incorporating organic and non-paraffinic phase change materials (PCMs) into hemp concrete. Different PCM contents, namely 5%, 10% and 15% of the binder mass, are considered. In this study, an extensive hygrothermal and mechanical experimental analysis was carried out on hempcrete-PCM composites. The incorporation of PCMs in hemp concrete resulted in a degradation of the mechanical strength, an enhancement of the thermal storage capacity, and no significant impact on the hygroscopic performance.