Hydration of Sr- and Ba-bearing sulphoaluminates in the presence of sulphates

The hydration process of Sr- and Ba-bearing sulphoaluminates in the presence of sulphates was investigated by isothermal calorimetry, DTA, XRD and SEM, and compared with that of 3CaO· 3Al₂O₃ · CaSO₄. The strengths of C₃A₃SrSO₄ with sulphates are higher, but the compressive strength of C₃A₃BaSO₄ with sulphate is lower than that of 3CaO·3Al₂O₃ · CaSO₄. The hydration of Sr-bearing sulphoaluminate is accelerated; moreover, the hydration of Ba-bearing sulphoaluminate is delayed in the presence of sulphates. The final hydrates of Sr- and Ba-bearing sulphoaluminates in the presence of sulphates were also defined.