Enhancing Mechanical Properties of Expansive Soil Through BOF Slag Stabilization: A Sustainable Alternative to Conventional Methods

• Published in: Minerals (Basel) 2024-11, Vol.14 (11), p.1145
• Main Authors: Mustafayeva, Arailym, Moon, Sung-Woo, Satyanaga, Alfrendo, Kim, Jong
• Format: Article
• Language: English
• Subjects: Activated clay; Additives; Agricultural pollution; Basic converters; Bearing capacity; Bentonite; Byproducts; Cement; Civil engineering; Clay; Compressive strength; Construction; Environmental sustainability; Expansive soils; Lime; Lime soil stabilization; Mechanical properties; Methods; Oxygen steel making; Particle size; Portland cement; Portland cements; Shear tests; Shear wave velocities; Slag; Soil bearing capacity; Soil improvement; Soil investigations; Soil lime; Soil mechanics; Soil properties; Soil shrinkage; Soil stabilization; Soil strength; Soil swelling; Stabilizers; Stabilizing; Steel production; Subgrades; Sustainability; Swell; Wave propagation; Wave velocity
• ISSN: 2075-163X; 2075-163X
• DOI: 10.3390/min14111145

This study investigates the stabilization of expansive soil using basic oxygen furnace (BOF) slag, an eco-friendly steel by-product, as an alternative to conventional stabilizers like ordinary Portland cement. By evaluating varying concentrations of BOF slag and lime as an activator, the research aims to improve the soil’s mechanical properties, addressing issues like low bearing capacity and high shrink–swell potential. Bentonite clay was treated with different BOF slag ratios (10%, 20%, and 30%) and activated with lime (1%, 3%, and 5%). After mixing and compaction, samples were cured and tested for unconfined compressive strength (UCS), shear wave velocity (BE), and free swell. Microscopic analyses (SEM) provided insight into structural changes post-stabilization, revealing improved properties with increased BOF and lime concentrations. Notably, stabilization with 30% BOF slag and 5% lime achieves a compressive strength of 810 kPa, meeting the minimum subgrade soil stabilization requirement (700 kPa) set by the Federal Highway Administration. This research underscores the potential of BOF slag as a sustainable and practical material for bentonite clay stabilization, offering a promising solution for enhancing soil properties while contributing to environmental sustainability through industrial by-product repurposing.