Finding new eco-binders as an alternative to conventionalPortland cement in construction activities has recently attracted many researchers worldwide. Thefeasibility of activating blended fly ash (FA)-ground granulated blast-furnace slag (GGBFS)by commercialNa2SO4to producesulfate-activated binder (SAB) was introducedin thisstudy. The SAB samples were prepared with different FA/GGBFSweight ratios of 5/95, 10/90, 15/85, 20/80, and 30/70. Resultsshow that the SABmixtures exhibited better flowability with more FA inclusion.Before 7 days, the mechanical strength of the SAB samplesdeclined with increasing FA content. However, the samples with 20 and 30% FA exhibited higher strength values at 28 days. Water absorption of the SAB samples was in the ranges of 12.29 –14.11%.Besides, the inclusion of more FA was beneficial in reducing the drying shrinkage of the SAB samples. The FA/GGBFS ratio of 30/70was recommended for producing SAB for green and sustainable construction.