Chloride and carbonation resistance of iron slag-recycled aggregates concrete with statistical and grey analysis

This study explores the durability performance of concrete incorporating iron slag (IS) as fine aggregate and recycled coarse aggregates (RCAs) as coarse aggregate, focusing on resistance to chloride ingress and carbonation – two key degradation mechanisms in concrete. Ten mixes with varying IS and RCA content were tested for durability, and the results were analysed using statistical tools and Grey Relational Analysis (GRA) to identify optimal combinations. The novelty lies in combining two industrial by-products – IS and RCA – within a single concrete matrix, offering both environmental and performance benefits. The findings reveal that concrete with 20% IS and 25% RCA exhibited superior resistance to chloride penetration and carbonation, validating their synergistic potential. The integrated analytical approach provides deeper insights into durability behaviour, demonstrating that sustainable aggregate alternatives can enhance concrete longevity. This research offers practical guidance for designing eco-efficient concrete, supporting the transition towards sustainable construction without compromising structural integrity.