FT-IR Study on Early-Age Hydration of Alkali-Activated Slag Cement
The hydration process of alkali-activated slag cement, especially at early-age, was studied by FT-IR, compared with that of Portland cement. The results show that during the hydration of alkali activated slag cement, two processes have taken place, the dissolution of Al3+ from the slag and then the recombination of Al3+ ions with the silicate anions. The former associated with the break of the glass network of slag and the later with the re-polymerization of the silicate and aluminosilicate anions. The rate of break of the glass network increases with the dosage of water glass, which completed in 24 h when the dosage of the water glass solution equivalent to Na2O exceeds 6% of the slag powder. It is confirmed by the IR study that Ca(OH)2 is absent in the hardened alkali activated slag cement paste.
Yiwang Bao, Danyu Jiang, Li Tian and Jianghong Gong
Y. H. Fang et al., "FT-IR Study on Early-Age Hydration of Alkali-Activated Slag Cement", Key Engineering Materials, Vol. 492, pp. 429-432, 2012