Sivrikaya, BurakDemir, İlhamiSevim, Özer2021-01-142021-01-1420202149-80242149-8024https://doi.org/10.20528/cjsmec.2020.02.003https://app.trdizin.gov.tr/makale/TXpjeU1qRTBOQT09https://hdl.handle.net/20.500.12587/13675Concrete has a significant place in construction structures, is a material that can be easily damaged due to incorrect design, incorrect material selection. Concrete may be damaged by physical and chemical factors. One of these factors is the alkali-silica reaction (ASR). ASTM C1260, is a short-term test method, and ASTM C227, is a longterm test method, are used to measure effect of alkali-silica reaction. In this study, the effect of fly ash additive use with 0, 5, 10, 15, and 20 wt.% replacement of cement was investigated in short- and long-term ASR test methods. For this purpose, while samples prepared for ASTM C1260 were kept in NaOH solution 14-days, samples prepared for ASTM C227 were waited 360-days in normal water solution. As a result; mortar bars with 20% fly ash additive ratio were classified as harmless for ASR in both test methods.eninfo:eu-repo/semantics/openAccessArticle62687210.20528/cjsmec.2020.02.003372214