Utilisation of palm oil fuel ash (Pofa) as sand replacement for fresh and hardened concrete by using powder and liquidation method

Palm oil fuel ash (POFA) is a waste material and generally disposed to open fields causing environmental pollution problems to the land and the air. Due to its abundance and high pozzolanic characteristics, it is highly potential to be used as civil engineering construction materials such as partial sand replacement in concrete. This paper presents the investigation of POFA as partial sand replacement in concrete. In doing so, two method of mixing processes were used namely powder and liquidation methods. The POFA was added in the concrete mix at various dosage levels of 0 %, 5 % and 10 % by weight of sand. Two types of testing were carried out; slump test for workability of fresh concrete identification and compressive strength test for strength identification of the hardened concrete cubes. The compressive strength test was carried out at 3, 7 and 28 days. The results from two different methods of mixing process were analysed, compared and discussed. From the results show that additional of 10 % of POFA by weight of sand is able to increase the strength of concrete at 28 days compared to other dosage levels. Hence, the POFA is given positive impact to be used as sustainable material in construction industry. (paper)