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

Abstract

Small angle neutron scattering (SANS) represents a powerful tool for the characterisation of the inner structure of technically relevant porous materials, e.g. hydrating cement pastes. Various parameters can be obtained by this non-destructive method, allowing repeated measurements as well as long term investigations, such as particle size distribution, specific inner surface, the scattering curve parameter A(2), etc. The latter describes the power law behaviour and can be correlated with fractality. It was shown that the observation window (size range of observable structures) can be modulated by the choice of the SANS instrument (observable Q-range). This paper describes and discusses the results of SANS investigations to study, first, the 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. particle size distribution of the pastes after one year of hydration. The time dependent changes (a) of the specific inner surface and (b) of the scattering curve parameter A(2) were quantified.