Experimental Investigation of Sunflower-Derived Materials as a Stabilizer for Geotechnical Improvements

Abstract

This study investigates the efficacy of sunflower seed powder as a natural and sustainable stabilizing agent for clayey soils through a series of controlled laboratory experiments. The treatment led to substantial changes in the soil's geotechnical properties. Plasticity characteristics were notably improved, with a 36% increase in the plastic limit and a 40% increase in the liquid limit, indicating reduced soil plasticity. A 36% decrease in specific gravity was observed, which may affect the soil's porosity and degree of saturation. The optimum moisture content decreased by 30%, while the maximum dry density decreased by 15%, suggesting improved compaction behavior and a lower risk of settlement. Mechanical strength properties exhibited significant enhancement: unconfined compressive strength increased by 113%, cohesion improved by 30%, and the angle of internal friction rose by 18.8%. Furthermore, the California Bearing Ratio (CBR) increased by 30%, supporting the material’s potential application in pavement subgrades. Observations of the cracking behavior revealed slight modifications in the pattern and a notable reduction in crack magnitude, implying enhanced structural integrity and durability of the treated soil. These findings collectively underscore the potential of sunflower seed powder as an environmentally friendly and effective soil stabilizer. Additional field-scale studies are recommended to assess its long-term performance and practical implementation in geotechnical engineering.