Zainal, Siti Harni, and Sarinah Ali. 2018. “Effect of Fly Ash And HDPE On Concrete Strength”. Politeknik & Kolej Komuniti Journal of Engineering and Technology 3 (1). Putrajaya, Malaysia:81-89. https://app.mypolycc.edu.my/journal/index.php/PMJET/article/view/522.