Evaluating the sustainability of using calcium carbide residue for clay stabilization: integrating mechanical...

This study addresses the imperative shift towards sustainability by exploring the viability of using calcium carbide residue (CCR) as a stabilizer for expansive clay, comparing it to hydrated lime. Integrating a mechanical characterization, and a life cycle assessment (LCA), the present research evaluates the environmental impact in terms of carbon emissions (CE), embodied energy (EE), and durability. Results show that, after three wet-dry cycles, soil stabilized with 9% CCR retains 51% unconfined compressive strength compared to 23% with 6% lime. The natural carbonation rate increases with an increase in curing time and contributes to the strength improvement in CCR-stabilized soil, specifically during the drying phase of wet-dry cycles. The presence of carbonate and CSH bonds in soil with 9% CCR is postulated to accelerate strength gain. The LCA reveals that more than 80% of the overall impact is attributed to the production phase of stabilizers. By shifting towards CCR, this research presents a promising solution to reduce the environmental footprint of construction materials, promoting a more sustainable approach to soil stabilization.