Exploitation of extruded polystyrene (XPS) waste for lightweight, thermal insulation and rehabilitation building applications

The present article investigates the possibility of Extruded Polystyrene (XPS) waste to be used as a lightweight aggregate in cement-based materials for structural applications. The developed material offers a promising solution for rehabilitation and energy efficiency upgrades of existing civil infrastructures, providing thermal insulation without adding excessive weight to reinforced concrete structures. Through a comprehensive experimental approach, this contribution evaluates the mechanical and thermal performance of cement-based composites with varying XPS content (up to 100 %) as sand replacement. Results demonstrate a balance between enhanced thermal insulation and maintained mechanical robustness, with optimal XPS content ranges identified for specific application needs. The incorporation of XPS waste into construction materials supports sustainability by repurposing non-biodegradable materials, while meeting the dual requirements of structural performance and energy efficiency. This research supports the exploitation of XPS-modified cement-based materials in structural rehabilitation of existing structures and innovative construction applications, promoting greener and more efficient building materials that could be utilized in ground structures, such as buildings. • Introduces XPS waste as a novel lightweight aggregate in cement-based materials for structural applications. • Enhances thermal insulation while maintaining mechanical robustness. • Achieves significant weight and density reduction of the material. • Identifies optimal XPS content ranges for different construction needs. • Promotes sustainable construction by repurposing non-biodegradable XPS waste in construction materials.