<![CDATA[The use of Portland cement as a binder results in high carbon emissions, making it necessary to find more environmentally friendly alternative materials. Fly ash-based geopolymer mortar can serve as an alternative, with the ratio of NaOH to Na₂SiO₃ activators being one of the factors influencing the mortar’s properties. This study aims to analyze the effect of the activator ratio on the setting time of geopolymer cement paste and the compressive strength of geopolymer mortar using the dry-mixing method. The study was conducted as a quantitative experiment using four variations of the NaOH:Na₂SiO₃ ratio: 0.5:2.5, 1:2.5, 1.5:2.5, and 2:2.5. Setting time was tested using a Vicat needle, while compressive strength was tested at 7, 14, and 28 days. The results showed that the higher the NaOH-to-Na₂SiO₃ ratio, the faster the setting time. Variation V1 yielded an initial setting time of 120 minutes and a final setting time of 165 minutes, while V4 yielded 75 minutes and 120 minutes, respectively. All variations exhibited an increase in compressive strength as the curing age increased. Variation V3, with a NaOH:Na₂SiO₃ ratio of 1.5:2.5, produced the highest compressive strength: 13.9 MPa at 7 days, 14.8 MPa at 14 days, and 19.7 MPa at 28 days. Thus, V3 represents the optimal activator ratio in this study.]]>
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