Data on ability of unground and ultrafine palm oil fuel ash in reducing mortar bar expansion due to alkali-silica reaction.

Data from SEM shows the surface structure of the unground and ultrafine POFA. Unground POFA surface structure is more porous compared to ultrafine POFA, where almost no porous found on the ultrafine POFA surface structure. Expansion graph shows that expansion of mortar bar due to the alkali-silica reaction (ASR). Mortar bar expansion which is more than 0.2% considered as highly reactive and below 0.1% considered as non-reactive. For unground POFA, as 40%-50% POFA replacement has the ability to reduce the mortar bar expansion below 0.1%. Compare to ultrafine POFA, mortar bar expansion can be reduced below 0.1% by replacement minimum 20%.