This study focuses on predicting the strength characteristics, including compressive strength and brittleness index, of lateritic soils stabilized with a periwinkle shell ash (PSA)-cement mixture. The Scheffe mix model, transformed using Osadebe’s principle, was employed to develop models that predict these properties. The validation of these models shows significant improvement in strength and durability with the addition of PSA. The interaction between PSA, cement, and water proves crucial in determining the optimal mix for enhancing soil strength. PSA is a promising ecofriendly alternative to conventional stabilizers in geotechnical applications