Mechanical and Microstructural Behavior of Clay Soil Stabilized with Metallic Tailing Powder

Abstract

Clay soils pose significant threats in construction due to variable strength and instability, particularly in moist conditions. This study investigates the use of tailing powder (TP), obtained by an ore factory in Jiangxi Province, China, as an alternative soil stabilizer to enhance the chemical, mechanical, and microstructural properties of clay soils for potential use in pavement applications. Various contents of TP (4, 6, 8, 10, 12, and 14%) were mixed with clay soil and subjected to different curing times (3, 7, 14, and 28 days). Effectiveness of stabilization was confirmed through laboratory tests like unconfined compressive strength (UCS), splitting tensile strength (STS), water stability, and resilient modulus. Finally, a small amount of TP improved the strength and durability, with an increase in UCS and STS as TP content and curing time increase. Hence, stabilized soil had a significant role in enhancing strength. UCS and STS increased from 2.89 to 10.12 MPa and 0.55 to 0.97 MPa, respectively, within a curing time increase from 3 to 28 days. X-ray diffraction (XRD) and scanning electron microscopy (SEM) the formation of cementitious compounds such as calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H) ettringite. Finally, TP was a viable and eco-friendly alternative to traditional stabilizers, offering better soil performance with reduced environmental impact. UCS improved by 71.44%, and STS by 43.30%, as TP increased from 4 to 14%. These findings showed an effective transformation of clay soils into suitable subgrade materials for pavement construction, solving both engineering and environmental issues.