Small angle neutron scattering from hydrating cement paste was compared to that from a paste made of a blend of cement and ground granulated blast furnace slag. The scattering measurements were used to determine the average size of the scattering particles during hydration. Their rate of growth was monitored in-situ over the first 40 hours of hydration. There was little difference in the scattering spectra, showing that the scattering particles in paste containing slag blend or cement were of similar size. At the beginning of hydration the particle radii were about 250 nn and after 14 days they had grown to over 600nm.
Estimates of particle sizes are critically dependent on the amount of multiple scattering. Therefore the amount of multiple scattering of the sample must be taken into account before making comparisons between the sizes of particles of different matrices.