The primary objective of the current study was to examine the strength and durability properties of a blend of geopolymer concrete (GPC) that included fly ash, lime, and slag cured at room temperature. For all mixtures, M25 grade concrete was used, which was designed in compliance with IS 10262-2019. Thirteen distinct concrete mix proportions were created, all with recycled coarse aggregate replacing 30%, 50%, and 100% of the NCA while keeping the alkalinity ratio and NaOH molarity unchanged. The concrete properties viz: workability, compressive strength, split tensile strength, ultrasonic pulse velocity (UPV), water absorption, density, sulphate attack and sorptivity were studied. Compressive strength, split tensile strength were determined at the ages of 7, 28 and 28 days respectively. The test results have exhibited that with increase in recycled aggregate replacement the strength declined. The decline in the strength is due to weak interfacial transition zone between the paste and aggregate. From the experimental results, it may be concluded that the desired strength of GPC can be obtained from a blend of fly ash with GGBS as it gives better results on compared to the other mixes even when 100% NCA were replaced with 100% RCA. Furthermore, empirical correlations were established to forecast split tensile strength from compressive strength and compressive strength based on density and UPV.