Properties of aerated concrete containing various amount of palm oil fuel ash, water content and binder sand ratio

Palm oil fuel ash (POFA), a waste by-product from palm oil mills, is continuously increasing in amount. The POFA which is disposed off by the Malaysian palm oil mills into landfills could be causing environmental pollution and there is a need to study the possibility of recycling this waste product. A study was carried out on the behavior of this agro based aerated concrete based on the usage of different ash replacement levels, water content and binder sand ratio. Initially, mortar cubes (70.6mm) containing various replacement levels of ash were produced and tested for their compressive strengths. From these results the optimum strength from the related replacement level (20%) of POFA was used to investigate further the properties of the mortar cubes due to water content and binder sand ratio. Tests carried out for compressive strength followed the procedures in BS 1881: Part 116. The results show that the integration of 20% POFA in aerated concrete could be used as the production of a new green product suitable for non structural applications. Study also suggests that appropriate water content is necessary to promote aeration process that is responsible for the lightness of this material. However, integration of too much water content may promote rupture of pores and bleeding thus diminishes the strength of concrete. Sufficient cement is vital for the binding of the fine aggregates thus promoting concrete with good strength.