Hydrating cement paste and SSNTD

The investigation on dry powder of silica fume, of ordinary Portland cement, a mixture of them and hardening Portland cement as well as Soli State Nuclear Track Detectors (SSNTD) with Small-angle Nuetron Scattering (SANS) experiments were relized on SANS facility of the JINR, Dubna, Russia. The exponents of the scattering curves of only dry Portland cement as well as dry silica fume deviate from -4 by about 4%. Therefore a estimate of the specific surface of these powder samples were given. In contrary the exponents reflecting the SANS behaviour of hardening cement pastes are varying in dependence on the hydration time (up to 620 days) and lie in an internal from about -2 to -4. Assuming o logarithmic normal distribuation for the geometric radius of spherical particles (pores or grains of different phases) the parameters of thes type of a particle size distribution (PSD) for hydrating samples within the first 92 days after the onset of hydration were determined. Furthermore, both laten t and etched tracks in PETP foils (SSNTD) wre studied. The radii of gyration Rg calculated from the scattering curve applying the Guinier approximation correlate with the radii measured by a gas penetration method.