Effect of unground palm oil fuel ash on acid resistance of oil palm shell lightweight aggregate concrete

The escalating quantity of industrial by-products, including oil palm shell (OPS) and palm oil fuel ash (POFA) of palm oil industry which are disposed off as a waste pollutes the environment. Recovering these wastes for product manufacturing would contribute decrease waste discarded at landfill. This research will study the acid resistance of oil palm shell lightweight aggregate concrete containing POFA as partial sand replacement. All concrete mixtures were produced by integrating OPS as coarse aggregate. Unground POFA was used as partial sand replacement up to 20% of fine aggregate. Specimens were immersed in acid solution for certain duration and measured its mass loss as well as compressive strength. Mix containing 10% POFA exhibit the highest resistance towards acid attack. The presence of higher amount of CSH gel and reduction in calcium hydroxide resulted in the lowest deterioration when exposed to an acidic environment. Conclusively, the use of unground fine POFA in concrete manufacturing can be an alternative method for sustainable construction.