Preliminary analysis of SANS data from hydrated cement paste

Full text: The microstructure of hydrated cement paste is investigated using the technique of Small Angle Neutron Scattering (SANS). The results from SANS measurements are dependent upon the thicknesses of the target materials. Reduction of target thickness is usually not a practical proposition owing to the difficulty in preparing sufficiently thin cement samples and also to the subsequent low count rates of the scattered beam relative to the transmitted beam. In this paper we present a method of analysis that takes advantage of the process of multiple scattering in thick samples. Using cement specimens, which are of different thicknesses, but are otherwise identical, SANS patterns with different degrees of multiple scattering have been obtained. It is shown how these measurements not only provide information about the shape and size of the scattering entities but also provide absolute values of the scattering contrast between the entities responsible for SANS and the matrix. This method of analysis has been used to analyse SANS data from hydrated cement paste. The data were collected on the Ultra High Resolution SANS Diffractometer at Oak Ridge National Laboratory, USA