Table : Degree of hydration calculated from the 29 Si and 27 Al NMR integrated intensities. In the case of the Na2Si1.7O4.4-activated samples, DOHSi was calculated using Equation ( ) and DOHSi' using Equation . The DOHs are given with an error of ± 0.05 due to the NMR decomposition of ill-defined peaks. If we now consider that the heat measured at the third stop (108 J/g) corresponds to only 25 % of reacted slag, as suggested by the NMR results, we get a maximum heat of hydration Qmax 3 of 432 J/g. New calorimetric degrees of hydration r(t) can be calculated with this value: