Palm Oil Fuel Ash as A Cement Replacement in Concrete

To produce concrete, cement is an essential material that binds together solid bodies but also is the largest producer of carbon dioxide (CO 2 ) emission. Up to 10% of global CO 2 emission comes from cement production thus making the sustainability of concrete a major issue that needs addressing. The processes of producing concrete consume heavily on natural resources such as sand, gravel, water, coal and crushed rock, mining of which damages the environment. It is however possible, that energy and cost efficiency can be achieved by reducing on the amount of clinker, and in its place utilizing partial cement replacements/pozzolans that require less process heating and emit fewer levels of carbon dioxide. This study investigates the effectiveness of agro waste ash by-product Palm Oil Fuel Ash (POFA) as an alternative material to replace Portland cement (OPC). Experiments were carried out by supplementing CEM I cement by weight in concrete mixes with POFA at 2.5%, 5%, 10%, 15% and 20% steps at the point of need, with water to cement ratio of 0.5. Results were compared with a control specimen, which was made with 100% cement. The results showed impressive compressive strength, especially at early age; in fact POFA specimens containing 2.5% and 5% POFA replacement displayed greater early compressive strength in comparison to the control, which is similar in behaviour to concrete containing silica fume which is an established partial cement replacement used in high strength applications. The results showed good repeatability and highlight the potential of POFA as an effective pozzolan which could enhance the sustainability and economic aspect of concrete.