In this study, fly ash (FA) is used to create geopolymer concrete (GPC), and FA is substituted with rice husk ash (RHA) in varying ratios of 20, 40, 60, 80, and 100%. The alkaline activator (AAC) utilised is a 10M solution of sodium hydroxide and sodium silicate (SS/SH). 400 kg/m3 of fly ash is present. The ratio of SS to SH is 2, while the ratio of AAC to binder (BI) is 0.4. The findings showed that the RHA-based GPC achieved less workability than the FA-based GPC, and that the slump value gradually declined as the RHA concentration in the mixes rose. The RHA-based GPC mixes have a marginally higher 7, 28, and 90 days compressive, split tensile, and flexural strength than FA-based GPC mixes, which is less than 10%. The strength of two separate source material-based GPC blends does not significantly differ from one another