The impact of intrinsic anhydrite in an experimental calcium sulfoaluminate cement from a novel, carbon-minimized production process

Calcium sulfoaluminate clinker produced through a previously described novel production process, generating further economies of carbon emission minimization and sulfur use efficiency, is tested for performance as a cementitious binder. The reactivity levels of major phases, including ye’elimite, two polymorphs of belite and anhydrite are found to produce a viable product characterized by rapid hydration. Through investigation, the reactivity is linked to the unique distribution of crystalline phases present within cement grains. It is inferred that both microstructure and mineralogy are responsible for the undesirable set behaviour encountered. The causality of this problem is further investigated and determined to be a consequence of the intrinsic anhydrite component for which remediation solutions are described. The resultant mortar compression strengths are determined for the subject cement in order to characterize its potential in relation to ordinary Portland cement.