This document studies the mechanical properties of geo-polymer concrete with ground granulated blast furnace slag (GGBS) and fly ash. Various mixes of GGBS and fly ash were used to create geo-polymer concrete, including 100% GGBS, 75% GGBS/25% fly ash, 50% GGBS/50% fly ash, and 25% GGBS/75% fly ash. The concrete was cured at room temperature for 7 and 28 days then tested for compressive strength. The highest compressive strengths were achieved with mixes containing a higher percentage of GGBS. Using industrial byproducts like GGBS and fly ash helps reduce greenhouse gas emissions compared to traditional cement concrete.