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The main objective of this study was to investigate the phase and strength development of calcium

sulfoaluminate-belite (CSAB) cement pastes with different amounts of gypsum and water.

Thermodynamic modeling and a series of experiments including X-ray diffraction (XRD), thermogravimetric analysis, isothermal calorimetry, and compressive strength tests were performed. Decreasing the mixing water increased the strength of CSAB pastes, but decreased the degree of hydration. Interpretation of the early age XRD results and thermodynamic modeling suggested the formation of a meta-stable phase from the hydration of belite, possibly C-(A)-S-H, which transformed into strätlingite at later ages only in the samples with …

This study investigated the hydration characteristics and strength development of calcium

sulfoaluminate-belite (CSAB) cements incorporating calcium carbonate (CC) powders with various

particle size distributions and different gypsum amounts. In general, the CSAB hydration was

accelerated by the CC powder, but the acceleration and resulting strength improvement were

more effective with finer CC powder. Regardless of the fineness of the CC powder, it took part

in the hydration of CSAB cement, forming hemicarboaluminate and monocarboaluminate phases.

These hydration and nucleation effects compensated for the strength reduction from decreased

cementing components (i.e., dilution effect) when finer CC powders were used, while they …