The current study aims to find out the impact of varying liquid to binder ratio, altering NaOH molarities, alkaline liquid ratios on the compressive strength of fly ashbased geopolymer mortars meant for retrofitting of concrete structural elements. By varying the liquid binder ratio as 0.35, 0.4 & 0.5. The molarities of NaOH were fixed as 10 M,12 M, and 14M. The ratios of alkaline liquid are considered as 1.5, 2.0, 2.5 and 3.0 and the studies are conducted. In total, 36 design mixes are prepared, and the compressive strengths were determined. Manufactured sand sourced locally is used in the mix in place of river sand. The increase in sodium silicate to silicate hydroxide ratio up to 2.5 resulted in improved compressive strength. The optimum parameters based on the determined strengths are ascertained. The optimum parameters for the values of NaOH molarity, liquid to binder ratio, and sodium silicate-to-sodium hydroxide ratio were determined as 12M, 0.4, and 2.5, respectively.