Geotechnical Investigation of Silicomanganese Slag as a Sustainable Fill Material for Reinforced Earth Retaining Wall Construction

AbstractThe increasing demand for construction materials and environmental concerns associatedwith industrial waste disposal have encouraged the exploration of alternative geomaterialsderived from industrial by-products. This study evaluates the suitability of silicomanganeseslag as a sustainable fill material for geotechnical applications through a comprehensiveexperimental investigation. The physical, hydraulic, mechanical, interface and environmentalcharacteristics of silicomanganese slag were assessed through laboratory testing, includingindex properties, compaction behaviour, permeability, shear strength, soil-geotextileinteraction, earth pressure response and leaching characteristics. The results demonstrate thatsilicomanganese slag possesses favourable characteristics of a frictional geomaterial,including low unit weight, high shear resistance, good drainage capacity and satisfactoryinteraction with geosynthetic reinforcement. The material also exhibited promisingperformance in reducing lateral earth pressure, although leaching studies identified elevatedmanganese release as an environmental limitation requiring site-specific evaluation and,where necessary, containment measures. Based on the overall evaluation, silicomanganeseslag is identified as a potential alternative to conventional fill materials for selectedgeotechnical applications such as lightweight embankments, retaining wall backfills andreinforced soil structures, subject to the environmental and durability considerationsdiscussed herein. The findings contribute towards the sustainable utilization of ferroalloyindustry by-products and promote circular economy approaches in geotechnical engineering.