Effect on consistency and performance of POFA concrete

This paper presents the experimental investigation conducted on Grade 30 concrete incorporating agro-industrial waste, Palm Oil Fuel Ash (POFA). The emergence of palm oil industry also creates other problem in waste management to our country. POFA was detected with high silica-alumina, being utilized as pozzolan which makes it as a good binding media similar to cement. In this paper, the specimens consist of 45 concrete cube size 100 x 100 x 100 mm at 3 different replacement level which were 0% as control specimen, 5% and 10% with two different techniques form which were powder and liquidation technique. The workability of fresh concrete properties was evaluated using slump test and flow table test and the performance of the hardened concrete was confirmed by cube compressive strength test at 3, 7 and 28 days. Based on the result, 5% POFA replacement using liquidation technique showed more workability compared to 10% POFA replacement. This phenomenon is due to the liquidation at POFA that acts as a liquid lubricant which can easily blend with cement component. However, concrete with 5% POFA using powder technique gives better result on the concrete performance. Powder technique shows better enhancement in strength as compared to liquid is due to the interaction between the raw POFA that's creates better bonding as compared to the POFA which was filled with water in liquid forms. (paper)