Concrete, renowned for its versatility, finds application in a myriad of purposes, adapting to diverse conditions. However, conventional concrete might fall short in meeting specific requirements for quality, performance, and durability. To address this challenge, a viable approach involves minimizing construction costs while enhancing structural concrete performance through the incorporation of suitable pozzolanic materials. This study focuses on replacing cement in concrete with ground granulated blast furnace slag (GGBFS). The primary objective is to investigate the fresh and hardened state properties of concrete with a high percentage of GGBFS replacement. The study examines the strength characteristics of concrete with 40%, 50%, and 60% replacement of cement by GGBFS. Four distinct concrete mix proportions were employed, and for each mix, standard-sized cubes, cylinders, and prisms were cast. Subsequently, these specimens underwent testing for compressive strength at 7 and 28 days, modulus of elasticity, and flexural strength at 28 days. The results obtained are then compared with those of conventional concrete, emphasizing the importance of resource conservation and sustainable development.