Utilization of Captured CO2 for Sustainable Ground Improvement through Carbon Mineralization in Soils
Utilization of Captured CO2 for Sustainable Ground Improvement through Carbon Mineralization in Soils
The use of low-carbon materials in ground improvement is increasingly important for reducing the environmental impact of geotechnical construction. This study investigates the feasibility of serpentinite rock powder, an ultramafic quarry by-product, as a dual-function soil stabilizer and carbon sequestration agent through mineral carbonation. A locally sourced silty sand was treated with 1%, 3%, and 5% serpentinite (by dry weight of soil) in combination with a biodegradable chelating agent (GLDA). Specimens were evaluated under normal curing (7 and 28 days) and under accelerated carbonation curing using pressurized CO2. Mechanical performance was assessed through unconfined compressive strength (UCS) testing, while carbonation behaviour was examined using pressure monitoring, X-ray diffraction (XRD), and total inorganic carbon (TIC) analysis. Under normal curing, strength enhancement was primarily attributed to physical filler effects and improved particle packing, with UCS increases of up to approximately 240% after 7 days. Carbonation curing significantly accelerated strength development, enabling specimens to reach peak strengths of approximately 215 kPa (5% serpentinite) within 24 hours. The rapid strength gain under carbonation curing is attributed to dissolution of magnesium-bearing phases from serpentinite and subsequent precipitation of hydrated magnesium carbonates within the soil matrix.Pressure reduction during curing indicated active CO2 consumption. XRD patterns showed additional diffraction features consistent with hydrated magnesium carbonate formation, and TIC measurements indicated progressive inorganic carbon increase with serpentinite dosage, reaching nearly 10%. The results suggest that serpentinite-driven mineral carbonation can provide rapid strength enhancement while enabling CO2 uptake. It is widely available as a quarry by-product in ultramafic rock regions, offering potential for valorization of low-value mineral residues.
Aaqib Ali; Mubashir Aziz; Arshad Raza; Mobeen Murtaza
11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)
Session 4: Sustainability in geotechnical systems
https://doi.org/10.53243/ICPMG2026-63