This study aims to investigate and optimize the proportion of Ground Granulated Blast Furnace Slag (GGBS), fly ash, and Nano silica in the replacement of Self-Compacting Geo-Polymer Concrete (SCGC) to enhance its performance in terms of strength, workability, and durability. The research focuses on evaluating the fresh properties of Normal Self-Compacting Concrete (SCC) and Self-Compacting Geo-Polymer Concrete (GPC) using NaOH and Na2SiO3 as activating agents. Tests such as slump flow, slump flow T50 cm, J-ring, v-funnel, v-funnel at t5 min, and L-box were conducted to assess the flow ability, passing ability, and workability of the concrete mixes. The results of the tests indicate that the concrete mixes largely satisfy the EFNARC Guidelines, with the optimized mix designs showing promising results. The slump flow values, T500mm slump flow time, V-funnel values, and L-box test results were within the specified range, demonstrating the suitability and effectiveness of the optimized mixes. The findings highlight the impact of GGBS content and Nano Silica addition on the flow and passing ability of the concrete mixes.