As expected, the conversion of the initially formed AFm phases to the thermodynamically stable katoite phase is not observed during the first 3 h. For the reference sample, C 2 AH 8 was found to be the main hydration product (8.0 . We attempted to quantify the C 2 AH 8 phase using the F-factor method described by Goergens based on the extracted scale factor. However, the resulting amount of 60 wt.% C 2 AH 8 calculated based on the internal standard method (using the inert quartz filler as internal standard) , in combination with the F-factor method , is almost six times higher than the maximum amount of all available C 3 A (5.55 wt.%) is converted to this hydrate phase. We assume that C 2 AH 8 preferentially precipitates at the interface of the polyimide film and is, therefore, over-determined compared to the other phases. Therefore, a quantification by Rietveld refinements was inaccurate for our suspension and was not further conducted for the experiments in the presence of sodium salts. Additionally, although we covered the samples with a polyimide film to prevent evaporation of the pore solution and carbonation of the sample, we also detected some hemicarbonate and monocarbonate (broad reflection between 10.0 -11.0 • ) (black triangle) in the reference mixture.