Abstract
This paper discusses the very early hydration of 12CaO·7Al2O3 glass containing Li20 compared with th at of 12CaO·7Al2O3 glass or 12CaO·7Al2O3 glass containing Na2O or K2O. These glasses were synthesized by fusion at 1500 °C and quenching. The hydration products of 12CaO·7Al2O3 glass containing 3mass% Li2O were C2AH8 and lithium aluminate hydrate by XRD at very early stage. But the hydration product of others is produced only C2AH8. The heat liberation of various types of 12CaO·7Al2O3 glasses was measured by isoperibol calorimeter.12CaO·7Al2O3 glass containing 0.5 mass% Li2O is the highest values of the heat liberation and the rate of heat liberation.
Therefore, because of its reactivity for hydration, 12CaO·7Al2O3 glass containing a small amount of Li2O is to be expected as the new type of accelerator for cement and concrete.
