S. N. . Shukor and M. Z. Noh, “Enhancing the Physico-Mechanical Properties of Concrete via Hydrochloric Acid Treatment on Palm Oil Fuel Ash Additives”, EKST, vol. 5, no. 2, pp. 307–316, Dec. 2025, Accessed: Apr. 07, 2026. [Online]. Available: https://penerbit.uthm.edu.my/periodicals/index.php/ekst/article/view/18399