REMARKABLE GEOTECHNICAL STATE-OF-THE-PRACTICE APPLICATIONS OF STEELMAKING SLAGS IN BRAZIL

Abstract

Steelmaking slags, particularly Linz-Donawitz (LD) and, recently, Kambara Reactor (KR) slags, have emerged as valuable materials in geotechnical engineering due to their distinctive interaction with different soils, generally enhancing the quality of geotechnical applications, due to their physical, chemical, and mineralogical properties. Espírito Santo, a Brazilian state, has developed a vibrant environment for geotechnical applications of these slags, leveraging the most relevant aspect of steelmaking slags: these industrial byproducts exhibit high mechanical strength, durability, and chemical reactivity, enabling significant improvements in soil stabilization, pavement base layers, and other earth structures construction. Incorporation of slags into soils enhances key geotechnical parameters such as maximum dry density, California Bearing Ratio, resilient modulus, and unconfined compressive strength, while also reducing plasticity and mitigating swelling and shrinkage in fine-grained soils. The environmental and economic benefits include waste valorisation, reduction in natural resource consumption, with potential to lower greenhouse gas emissions compared to traditional stabilizers like Portland cement and lime. Challenges related to volumetric expansion and chemical variability are addressed through processing, aging, and quality control measures. Synergistic use with other industrial byproducts further optimizes mechanical performance and sustainability. Advances in testing, characterization, and life cycle assessment support the safe and effective application of these residues, aligning with circular economy principles and regulatory frameworks. Ongoing research focuses on mixture optimization, long-term durability, and innovative treatment methods to expand the applicability of slag-based geomaterials in sustainable infrastructure development.