Lightweight gypsum composite material to improve energy efficiency: Assessment of physico-chemical, mechanical, thermal and fire performance properties

Abstract

This study addresses the development of a new composite material made under circular economy criteria using natural and recycled resources. Recycled expanded polystyrene is innovatively integrated into the matrix of gypsum-based materials reinforced with fibers. This approach has progressively reduced the consumption of raw materials up to 18.2%, resulting in a reduction of 31.7% in density. This results in a reduction of 47.2% thermal conductivity compared to conventional gypsum and an improvement in the energy efficiency of the construction systems, increasing their thermal resistance by up to 21.1%. Additionally, the mechanical characterization results comply with the minimum regulated requirements. Physico-chemical characterization and material’s microstructure analysis were also conducted. Finally, an assessment of the material’s behavior under fire conditions is included, analyzing the hazard emissions released. This study contributes to the development of new sustainable construction materials to produce more energy-efficient prefabricated products. © 2025 CSIC. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International (CC BY 4.0) License.