Mechanical characteristics and service life of concrete based structures are two crucial aspects of concern. Engineers are seeking the enhanced mechanical strength and decreased permeability of cementitious structures with the incorporation of pozzolanic additives that has the potential to develop the matrix with their nucleation and filler effect. At the same time, concern is also oriented towards having proper workability and setting time. The current study is focused to meticulously evaluate and fine-tune the dosages of zinc oxide (ZO) in microsilica (MS) based concrete to attain the optimal workability and the intended concrete characteristics. The content of ZO has been varied from 0.3–1.2% for substituting cement in presence of 12% MS. The findings suggest that when the increased dosage of ZO reduces the time of setting. Additionally, there is an observed increase in consistency and mechanical strength, which leads to improvements in the microstructure of the material. These enhancements are most pronounced at the optimal dosage of ZO (0.9%). The confirmation of the results has been achieved through the utilisation of SEM and XRD analysis. Thus, the utilization of the optimal dosage of pozzolanic additives is highly desirable to effectively enhance the structural properties of concrete.