Journal of Engineering Science and Technology Vol. 15, No. 4 (2020) 2361 - 2378 © School of Engineering, Taylor’s University 2361 FEASIBILITY STUDY OF PALM BOILER ASH AS CEMENT AND SAND REPLACEMENT IN CONCRETE AZMI ROSLAN 1, *, MOHAMED KHATIF TAWAF MOHAMED YUSOF 2 , SITI SHAHIDAH SHARIPUDIN 2 , ZENO MICHAEL 3 , ILYA IZYAN SHARUL AZHAR 3 1 Faculty of Chemical Engineering, Universiti Teknologi MARA, Pasir Gudang Campus, Jalan Purnama, Bandar Seri Alam, 81750, Masai, Johor, Malaysia 2 Faculty of Civil Engineering, Universiti Teknologi MARA, Pasir Gudang Campus, Jalan Purnama, Bandar Seri Alam, 81750, Masai, Johor, Malaysia 3 Faculty of Mechanical Engineering, Universiti Teknologi MARA, Pasir Gudang Campus, Jalan Purnama, Bandar Seri Alam, 81750, Masai, Johor, Malaysia *Corresponding Author: azmiroslan@uitm.edu.my Abstract In this paper study the properties of Palm Boiler Ash (POBA) as sand and cement replacement in concrete and identify optimum level of replacement. Besides that, pozzolanic activity of the POBA to OPC also has been assessed. Samples were tested to measure its compressive strength, ultra-pulse velocity (UPV), and thermal conductivity of blended concrete. Three replacement level of sand and cement has been employed which are 5%, 10%, and 15%. It is found that, increased in the POBA replacement level in the cement mixture will linearly reduce the compressive strength of concrete mixture. From perspectives of pozzolanic activity, it is increases as amount of POBA replacement increases. For UPV values, it is decreases as POBA replacement increases. Among those three percentage of sand and cement replacement, 5% POBA replacement is the most optimum quantity of the POBA replacement in the concrete as it shows a high compressive strength when tested for compression strength, good quality of concrete grade and thermal conductivity of 1.54 W/m.K. Keywords: Cement replacement, Concrete, Palm oil boiler ash (POBA), Sand replacement.