Revolutionizing Concrete: Performance Enhancement and Elemental Insights with Electric Arc Furnace (EAF) Slag Replacement

Abstract

This study explores the influence of Electric Arc Furnace (EAF) slag particle size and replacement percentage on the engineering performance of concrete, providing valuable insights into its optimal utilization for sustainable construction. By analyzing particle size ranges—R1 (0.8–2.36 mm), R2 (2.36–4.75 mm), and R3 (4.75–7.0 mm)—this research highlights their distinct contributions to compressive strength and carbonation potential. Medium-sized particles (R2) emerged as the most suitable due to consistent compressive strength across different replacement percentages, high calcium content, and superior carbonation efficiency, leading to the highest calcium carbonate formation and CO2 uptake. The novelty of this work lies in integrating advanced analytical techniques, including Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), to elucidate the microstructural mechanisms driving these performance enhancements. The findings establish a quantifiable relationship between EAF slag’s high calcium and magnesium oxide content and its role in mechanical improvements and carbon dioxide sequestration via mineral carbonation reactions, with R2 achieving the highest CO2 uptake. This comprehensive approach addresses the apparent contradiction between early-stage and long-term performance, emphasizing R2’s suitability, with 45% of the replacement of fine aggregate as the optimal choice for sustainable high-performance concrete with superior strength stability and carbonation efficiency.