Exploring the Potential of Iron Slag and Stone Ash as Aggregate Replacements for the Improvement of the Compressive Strength and Durability of Self-Compacting Concrete

Industrial by-products, such as Iron Slag (IS) and Stone Ash (SA), can replace aggregates in concrete, but research on their mechanical performance and durability, particularly in Self-Compacting Concrete (SCC), is still limited. Using these materials supports sustainable construction principles while improving material efficiency. This study evaluates the effect of replacing coarse and fine aggregates with Iron Slag and SA, respectively, on the compressive strength, durability, and practical implementation of concrete in structural applications. The research was conducted experimentally with four SCC concrete mix variations: BSI-N (control), BSI-1 (0% SA), BSI-2 (50% SA), and BSI-3 (100% SA). Tests included compressive strength, slump flow, density, porosity, sorptivity, electrical resistivity, chloride penetration, and abrasion resistance, based on ASTM and SNI standards. The results show that BSI-3 (100% SA) had the highest compressive strength (50.40 MPa) and the lowest porosity and abrasion values, but failed to meet SCC criteria due to a slump flow below 550 mm. Conversely, BSI-2 met SCC specifications with a slump flow of 650 mm, showing the best chloride penetration resistance, while it maintained an adequate compressive strength of 44.38 MPa. It was concluded that an SCC mix with 50% SA and IS (BSI-2) is optimal for industrial building applications, particularly for floor slabs and supporting structures, as it balances strength, durability, and workability.