This research was conducted to study the aggregate impact value (AIV) of fly ash geopolymer artificial aggregate at different sodium hydroxide (NaOH) concentration. This research involves five different concentrations of NaOH solution which are 6M, 8M, 10M, 12M and 14M while ratio of NaOH/NaSi2O3 is constant at 2.5. In this study, the ratio of solid to liquid is fix at 3.0. The characterization of fly ash was observed by Scanning Electron Microscope (SEM). Results show that, the sample with 12M of NaOH concentration give the lowest percentage of AIV (22.43%) which denotes a high performance of aggregate in concrete field and also contribute to high performance of concrete while 6M of NaOH concentration gives the highest percentage of AIV (26.95%). The tested results indicated that the significant potential of fly ash geopolymer aggregate as an alternative artificial aggregate in construction materials field.
