Examining the hydration mechanism of supersulfated cements made with high and low-alumina slags

Supersulfated cements (SSC) are normally produced from granulated blast-furnace slags having high-alumina content. However, such slags are not produced in North America. In this study, SSC mixtures were produced using two different slags, one high in alumina content (13%) and the other low in alumina content (7%). The purpose of this study was to investigate the differences in hydration mechanisms of SSC produced with the two types of slag. The low-alumina slag SSC mixtures showed a lower degree of slag hydration and quantities of hydration products formed (C-S-H and ettringite), ultimately resulting in higher porosity and poor mechanical performance of the SSC mixtures compared to high-alumina slag mixtures. A better mechanical performance of SSC mixtures made with low-alumina slag may be achieved by increasing its rate of glass slag dissolution.