Improvement of Silts and Clays Soil Stabilized with Cement, Coarse Aggregate, and Chemical Additives from the Laboratory to the Field

In many infrastructure projects, existing subgrade soils often fail to meet engineering standards, particularly silts and clays, which exhibit high swelling potential and low strength. To address these deficiencies, stabilization using cement, coarse aggregates, and chemical additives is necessary. This study investigates the combined effects of cement, coarse aggregate, and chemical additives on the improvement of soil properties, both in laboratory and field applications. The experimental program included California Bearing Ratio (CBR), Unconfined Compressive Strength (UCS), and swelling tests conducted under soaked and unsoaked conditions at 7 and 28 days. Two types of field trials were implemented: (1) cement and chemical additive combinations applied on a 25 m test section, and (2) extended road applications up to 19 km using varying dosages of cement, chemical additives, and coarse aggregates. The results indicate that cement and chemical additives significantly increased CBR and UCS values while reducing swelling potential. The findings demonstrate that cement combined with chemical additives can effectively replace coarse aggregates as a stabilizer, providing an economical and environmentally friendly solution for expansive soil stabilization.