CO ₂ ‐Mineralized EAF Slag for White Cement: Hydration, Performance, and Comparison to GGBFS

Abstract

This project investigates the use of CO ₂ ‐mineralised white Electric Arc Furnace (EAF) slag as a supplementary cementitious material in white Portland cement systems. The study aims to evaluate whether carbonated EAF slag can partially replace white clinker while maintaining the aesthetic and performance requirements of white cement. Cement blends containing 20% and 30% mineralised slag were compared with a white cement reference and a GGBFS‐based reference. The materials were characterised in terms of chemical and mineralogical composition, particle size distribution, Blaine fineness, and brightness. Hydration behaviour was assessed by isothermal calorimetry, while mechanical performance was evaluated through compressive and flexural strength testing. The results indicate that CO ₂ ‐mineralised EAF slag can be incorporated into white cement with low impact on brightness and with measurable effects on hydration kinetics and strength development. Although the very high fineness of the mineralised slag must be considered when interpreting reactivity and water demand, the findings highlight its potential as a low‐carbon alternative SCM for white cement applications, comparable to the GGBFS performance.