Effect of Fly Ash, MgO and Curing Solution on the Chemical Shrinkage of Alkali-Activated Slag Cement

The chemical shrinkages of alkali-activated slag cement (AASC), and the effect of fly ash, MgO burnt at 900 degrees C and the curing solutions were studied. The shrinkages were compared with that of ordinary portland cement (OPC). The results show that the chemical shrinkage of AASC is lower than that of OPC. Adding fly ash and light-burnt MgO reduced the early age chemical shrinkage, while the shrinkage-reduction effect decreased with the age. The alkality of the curing solution has significant effect on the hydration and shrinkage of AASC. The chemical shrinkage of AASC increased with the alkali concentration of the curing solution. The mechanisms of fly ash, MgO and curing solution on the shrinkage were discussed.