Mechanical performance and sustainability assessment of cold-formed thin-walled steel-polystyrene foam concrete composite wall panels

• The proposed wall panels exhibited excellent compressive and seismic performance. • FE simulations accurately predicted mechanical performance and enabled parametric study of composite wall panels. • Prototype implementation validated significant construction cost reduction by the proposed system. • The unit-area carbon emissions of the prototype project were only 53.32 % of the typical residential buildings. Prefabricated buildings have recently attracted considerable research interest due to their advantages in construction efficiency and sustainability. In this paper, the mechanical performance of wall systems, alongside construction costs and carbon emissions, has become a critical focus requiring comprehensive investigation. This study proposed a novel cold-formed thin-walled steel–polystyrene foam concrete composite wall panel. Axial compression and hysteretic tests were conducted on six full-scale specimens with varying concrete densities to experimentally assess their mechanical behavior. Finite element (FE) simulations were subsequently performed to evaluate compressive performance and conduct a parametric study. Furthermore, a prototype house was constructed to evaluate the sustainability of the proposed system. The results demonstrated that the composite panels exhibited excellent compressive and seismic performance. In the axial compression tests, the yield load, ultimate load, and stiffness increased with concrete density. Similarly, in the hysteretic tests, the peak load, lateral stiffness, initial-cycle energy dissipation capacity, and viscous damping coefficient all showed positive correlations with increased concrete density. The FE simulations accurately captured the structural behavior. Implementation of the proposed wall panel system in a prototype residential project demonstrated significant advantages, reducing total construction costs by 23.83 % compared to conventional prefabricated concrete structures and shortening the construction period by approximately 70 %. Life-cycle carbon emission analysis indicated unit-area emissions of 274.44 kgCO₂e/m², representing only 53.32 % of the average for typical residential buildings. These findings validate the proposed system as a cost-effective and environmentally sustainable solution for modern prefabricated construction.