To control the release of CO2 into the environment, calcium sulfoaluminate (CSA) cement, supplementary cementitious materials (SCMs), and their blends have been studied in detail to replace the use of Portland cement (PC) [1,2]. Furthermore, the replacement of CSA cement with SCMs has been carried out toward the development of clinker-free binder systems, yet the
substitutions with SCMs at high dosages can result in the degradation of microstructure and corresponding strength loss due to the low reaction degree of SCMs [1-3]. Against this backdrop, this paper revisits previous studies of CSA cement systems blended with SCMs and summarizes their binder chemistry and strength development. In addition, a preliminary study pertaining to the microstructural evolution of slag-blended CSA cement systems and the effect of MgO-NaOH incorporation on the reaction degree of slag carried out by the authors will be introduced [4].