SOME FACTORS AFFECTING EARLY HYDRATION OF ALKALI-SLAG CEMENTS

This paper deals with the effect of activator dosage, temperature and water-to-slag ratio on early hydration of alkali-blast furnace slag ce ments activated with NaOH, Na2CO3 or Na2SiO3. A conduction calorimeter was used to monitor early-age hydration. The experimental results ind icate that activator dosage, temperature and water-to-slag ratio have a significant effect on heat evolution rate, induction Period and cumu lative heat of hydration; the effect varies with the nature of activat or. Hydration of Na2SiO3 activated slag appears to be the most sensiti ve to the variation of activator dosage, temperature and water-to-slag ratio among NaOH, N2CO3 and Na2SiO3 activated alkali-slag cements.