Hydration mechanism of gehlenite glass cements

Calcium aluminosilicate glass cements are produced by quenching a liquid from 1600°C to room temperature. After grinding and mixing with water, the glass cements hydrate without activators and develop good mechanical properties. The glass cements based on compositions close to gehlenite develop better mechanical properties than those giving hydrogarnet during their hydration. This study is a tentative attempt to give an explanation to these phenomena. Classical technique have been used: XRD, microcalorimetry, conductimetry and scanning electron microscopy. It is found that the high mechanical strengths of the glass cements giving gehlenite hydrate as the main hydration product are due to the compact microstructure of this hydrate.