Study on synthesis and performance of alite-strontium calcium sulfoaluminate cement

Synthesis conditions and performance of a novel alite-strontium calcium sulfoaluminate cement are reported: the clinker composition is modified from that of Portland cement. The mineral composition and the microstructure of the clinker were analysed by X-ray diffraction (XRD) analysis, scanning electron microscopy–energy dispersive X-ray spectrometry (SEM–EDS) and lithofacies. The results show that strontium calcium sulfoaluminate and the minerals of Portland cement clinker can coexist in one clinker system. The optimal composition of alite-strontium calcium sulfoaluminate clinker is as follows: strontium calcium sulfoaluminate 9% (mass %), C₃S 59·35%, C₂S 14·14%, C₃A 7·50%, C₄AF 10·00%. The content of strontium calcium sulfoaluminate produced during the sintering process at 1380°C is high. The compressive strength of the cement prepared under the testing conditions reaches 30·5 MPa, 58·4 MPa and 122·2 MPa at 1 day, 3 days and 28 days curing ages, respectively.