Self-consolidating concrete (SCC) is one of the innovative products in concrete technology that has been developed in recent years. However, many researchers are still trying to optimize the mixture proportions and investigate the incorporation of new materials in SCC. The typical high content of portland cement in SCC is one of the main challenges in optimization of its mixture proportions. This high cement consumption increases the production cost of SCC and, considering the large amount of CO2 emitted during portland cement production, is also undesirable from an environmental point of view. In this study, two approaches were employed to lower the portland cement content in SCC mixtures, namely, adopting a dense aggregate grading and partially replacing portland cement with natural zeolite. Portland cement was replaced by natural zeolite at different percentages to investigate the effect of this natural pozzolan on the fresh and hardened properties of the SCC mixtures. Fresh properties of the S...