Performance of Palm Oil Fuel Ash and Rice Husk Ash Based Geopolymer Mortar Dhabit Zahin Alias Tudin, Ahmad Nurfaidhi Rizalman and Hidayati Asrah E3S Web Conf., 65 (2018) 02011 Published online: 26 November 2018 DOI: 10.1051/e3sconf/20186502011