Enhancing Soil Stabilization with Multi-walled Carbon Nanotubes

Soil stabilization, widely used to enhance soil engineering properties, typically involves replacing weak soils incapable of supporting structural loads with stronger ones or fortifying them using mechanical and/or chemical methods. While mechanical compaction at specific moisture levels effectively improves soil properties, it often falls short for weak soils. Lime and cement have long been used as chemical stabilizers. Recent advancements in materials manufacturing have, however, introduced nanomaterials as a promising alternative for significantly improving construction materials. This study explores the use of carbon nanotubes (CNTs), given their exceptional properties, for soil stabilization. Different percentages of CNTs (0.001%, 0.01%, and 0.1%) were integrated into a soil-cement matrix, using TritonX 100 (1% concentration) as a dispersion agent. Several tests, including unconfined compressive strength (UCS), direct shear strength, and water absorption, were conducted to evaluate the stabilized soil's performance. The results demonstrated that an optimum CNT content of 0.01% significantly enhanced the soil's overall properties, with a remarkable 360% increase in UCS observed after 28 days of curing. Cohesion values reached 71.03 kPa at 28 days, marking a 104.5% improvement compared to CNT-free samples. Additionally, samples with 0.001% CNT exhibited excellent water absorption resistance, remaining intact for 72 h with a total absorption value of 8.7%.