Eco-efficient ultra-high-performance concrete formulation utilizing electric arc furnace slag and recycled glass powder–advanced analytics and lifecycle perspectives

Abstract

Ultra-high-performance concrete (UHPC) is a promising material for sustainable and resource-efficient construction, but its high Portland Cement content poses environmental challenges. This research proposes an optimized UHPC blend that significantly reduces the Portland Cement dosage by incorporating industrial waste materials [i.e., Recycled Glass Powder (RGP) and Electric Arc Furnace Slag (EAFS)]. The integration of these waste materials in UHPC formulation addresses critical waste management issues and aligns with sustainable construction practices. Utilizing a tri-variable Design of Experiments methodology in conjunction with the Andreasen & Andersen theory, the research aims to reduce Portland Cement in UHPC without compromising its compressive strength and rheological behavior. The optimized blend incorporates RGP and EAFS, achieving the threshold compressive strength established by ACI-239 (150 MPa) while maintaining a self-compacting performance in the fresh state. This mixture features low cement (621 kg/m³) and silica fume (100 kg/m³) content. Life cycle assessments (LCA) were conducted to examine the environmental efficiency of the optimized blend. A comparative LCA demonstrates that the optimized UHPC mixture developed in this study surpasses a control mixture with higher cement and silica fume contents while maintaining comparable mechanical and rheological properties. Notably, this improvement is highlighted by a nearly 20% reduction in CO2 equivalent emissions. The scientific significance of this study lies in its demonstration of a viable pathway to producing UHPC with reduced environmental impact, contributing to the advancement of sustainable building practices, and offering a practical solution to waste management issues.