Nanostructural investigations of hydrating cement pastes produced from cement with different fineness levels

Small angle neutron scattering (SANS) represents a powerful tool for the ch aracterisation of the inner structure of technically relevant porous materi als, e.g. hydrating cement pastes. Various parameters can be obtained by th is non-destructive method, allowing repeated measurements as well as long t erm investigations, such as particle size distribution, specific inner surf ace, the scattering curve parameter A(2), etc. The latter describes the pow er law behaviour and can be correlated with fractality. It was shown that t he observation window (size range of observable structures) can be modulate d by the choice of the SANS instrument (observable Q-range). This paper des cribes and discusses the results of SANS investigations to study, first, th e time dependent behaviour of the microstructural changes within the first 68 days of hydration, i.e. the scattering curve parameter A(2), and second, the influence of the different granulometric characteristics, i.e. particl e size distribution of the pastes after one year of hydration. The time dep endent changes (a) of the specific inner surface and (b) of the scattering curve parameter A(2) were quantified.