This document summarizes a research project investigating how the addition time of superplasticizer affects the rheological properties of self-consolidating cement paste. The project aims to understand how mixing procedures and addition sequence influence the robustness of SCC mixtures. Test results show that for a VMA-type mix design, rheological parameters are more sensitive to the addition time of superplasticizer compared to variations in water content, while a powder-type mix design shows the opposite. Tests also indicate that limestone filler has a more significant influence on rheological properties than the presence of VMA, type of superplasticizer, or use of silica fume and fly ash.