VERY EARLY HYDRATION OF LI2O-CAO-AL2O3-SI O2 GLASS

This paper discusses the very early hydration of 12CaO . 7Al(2)O(3) gl ass containing Li2O compared with that of 12CaO . 7Al(2)O(3) glass or 12CaO . 7Al(2)O(3) glass containing Na2O or K2O. These glasses were sy nthesized by fusion at 1500 degrees C and quenching. The hydration pro ducts of 12CaO . 7Al(2)O(3) glass containing 3 mass% Li2O were C(2)AH( 8) and lithium aluminate hydrate by XRD at very early stage. But the h ydration product of others is produced only C(2)AH(8). The heat libera tion of various types of 12CaO . 7Al(2)O(3) glasses was measured by is operibol calorimeter. 12CaO . 7Al(2)O(3) glass containing 0.5 mass% Li 2O is the highest values of the heat liberation and the rate of heat l iberation. Therefore, because of its reactivity for hydration, 12CaO . 7Al(2)O3 glass containing a small amount of Li2O is to be expected as the new type of accelerator for cement and concrete.