Irnawan, M.C. and Lubis, R.R.A. 2026. Behavioral Study of Soft Soil Beneath the Embankment Improved by Columns Derived from Recycled Concrete Aggregate and High-Calcium Fly Ash-Based Geopolymer. Engineering Science Letter. 5, 03 (Oct. 2026), 286–291. DOI:https://doi.org/10.56741/IISTR.esl.002462.