Novel extruded polystyrene lightweight thermoinsulating cement mortar: Experimental investigation of the mechanical behaviour

The construction sector is a significant contributor to global waste, primarily due to the extensive use of non-renewable resources and the accumulation of non-biodegradable waste such as Extruded Polystyrene (XPS). The present article investigates the exploitation of XPS waste as a lightweight aggregate in cement-based mortars, with a focus on mechanical and thermal insulation properties. XPS was incorporated in varying concentrations (from 0 % to 100 % by volume), replacing standard sand to assess its impact on mortar composites. The results indicate that, while increasing XPS content leads to a reduction in flexural strength, the material remains viable for structural applications. Moreover, the exploitation of XPS significantly enhances the thermal insulation properties, making it a suitable candidate for energy-efficient construction. These findings highlight the potential of XPS-modified mortars in reducing the environmental footprint of the construction industry while providing functional benefits for lightweight and thermally efficient building materials.