Effect of Palm Oil Fuel Ash on Alkali-Silica Reaction of Mortar

Abstract

This research aimed to study the effect of palm oil fuel ash (POFA) on the alkali-silica reaction of mortar. POFA was ground until the particles were retained on a sieve No. 325 by 33±1 and 5±1% by weight. Ground POFA was then used to replace Portland cement type I at 10, 20, 30 or 40% by weight of binder to investigate the alkali-silica reaction of mortar. The ratio by weight between binder to fine aggregate of 1 to 2.25 was used; a highly reactive aggregate was also used to cast a mortar. A constant water to binder (w/b) ratio of 0.47 was used for all mortar mixtures. After casting for 24 h, mortar bars were cured in water at 80°C for a period of 24 h. The bars were then immersed in 1 N of sodium hydroxide (NaOH) solution at 80°C for a period of 28 days. The results showed that POFA of both high and low finenesses, which were used to replace Portland cement, could reduce the alkali-silica reaction in mortars. Moreover, using a higher amount of POFA, either with high and low finenesses, could reduce more expansion of mortars due to the alkali-silica reaction.