ABSTRACT In recent decades, greenhouse gas emission and global warming are the major threat to climatic change variability. The quality of concrete can be enhanced by the addition of a supplementary cementitious material to portland cement. In this study, fly ash is utilized as a supplemental cementitious material (SCM). The purpose of this research is to test and study the mechanical and thermal properties of blended concrete containing ordinary portland cement, fly ash and zinc sulphate as well as to investigate the microstructure in order to study the influence of zinc sulphate on the hydration process of concrete. This research mainly focused on the changes occurring in the strength, retarding mechanism, setting time, mineralogy, and microstructure caused by the addition of zinc sulphate in concrete. Ordinary portland cement, fly ash, pulverized fly ash and zinc sulphate are used in the blended concrete. The varied proportions of fly ash and zinc sulphate in the mix are 15%, 30%, 45%, and 60% respectively. The strength characteristics can be increased by fly ash pulverization. Hence the research focuses in exploring the addition of fly ash, pulverized fly ash and zinc sulphate anhydride to the concrete mix.