Hydrothermal Reaction and Hardening Properties of Fly Ash

　Since fly ash consists mainly of vitreous phase, the present suthore supposed that gelling should be applied to it for manufacturing lightweight concretes. Lime and gypsum were chosen as reactants with fly ash to form calcium sulphoaluminate hydrates and C-S-H by gelling, as fly ash is rich in SiO₂ and Al₂O₃content.
　In this report, gelling and hardening properties of five kinds of fly ash were invesitigated following the previous report where these properties were compared among fly ash, granulated blastfurnace slag and volcanic ash.