Carbonation-Driven Soil Stabilization Using Reactive Mafic and Ultramafic Rock Dusts in Climate-Adaptive Geotechnics

The integration of sustainable materials in geotechnical engineering is crucial to advancing climate-resilient infrastructure. This study investigates the dual role of basalt and peridotite rock dusts as eco-efficient soil stabilizers and carbon-sequestering agents. A silty sand typical of arid environments was treated with varying proportions of these rock dusts in combination with a biodegradable chelating agent (tetrasodium glutamate diacetate), and subjected to controlled carbonation to evaluate strength development, compaction characteristics, microstructural evolution, and CO2 mineralization potential. The results revealed a substantial increase in unconfined compressive strength, with peridotite-treated specimens achieving up to 205 kPa-a 286% enhancement over untreated soil. Total Inorganic Carbon (TIC) analysis and X-ray diffraction (XRD) patterns confirmed significant carbonate precipitation, particularly in magnesium-rich peridotite systems. Microstructural evidence from scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) corroborated pore infilling and mineral binding as dominant mechanisms behind strength gain and densification. The outcomes demonstrate that ultramafic and mafic rock dusts can effectively replace energy-intensive cementitious stabilizers while serving as long-term CO2 sinks, offering a scalable, low-carbon pathway for sustainable ground improvement. This integrated approach supports carbon-negative geotechnics and aligns with the broader goals of climate-adaptive infrastructure development.