Validity of recent approaches for statistical nanoindentation of cement pastes

In this paper we proceed in the examination of different aspects of the application of statistical nanoindentation to hydrated cement pastes for determining the mechanical properties of the single phases. In particular, we evaluate the size of the uniform domains of hydration products in a volume of cement paste obtained by Focussed-Ion Beam Nanotomography and we show that the uniform domains are too small to origin separate peaks in the frequency plots. Finally, we show that the procedure of fitting the frequency plots by Gaussian distributions of different sizes is not robust and heavily relies on assumptions about the elastic properties of the different phases.