EFFECTS OF QUARTZ PARTICLE-SIZE ON HYDROGARNET FORMATION DURING AUTOCLAVING AT 180-DEGREES-C IN THE CAO-AL2O3-SIO2-H2O SYSTEM

The effects of quartz particle size on the nature of hydration product s in unstirred, autoclaved metakaolin-lime-quartz slurries with Ca/(Al + Si) and Al/(Al + Si) ratios of 0.80 and 0.13 were investigated. Whi le hydrogarnet invariably appeared before 11 Angstrom tobermorite when using either fine or coarse quartz, its formation was more prominent in the presence of coarse quartz. The breakdown of hydrogarnet and the formation of 11 Angstrom tobermorite were delayed in the presence of coarse quartz, suggesting that when using aluminous additives under au toclaving conditions, quartz fineness is a deciding factor. The amount of hydrogarnet formed during autoclaving followed by its breakdown is significant in relation to the formation of 11 Angstrom tobermorite. (C) 1998 Elsevier Science Ltd.