The composition of cement hydrating at 60 deg C from synchrotron radiation

Abstract

Cement consists of 5 phases C3S, C2S, C3A, C4AF (where C denotes CaO, S denotes SiO2, A denotes AI2O3 and F denotes Fe2O3) and gypsum. When cement hydrates it forms an amorphous calcium silicate hydrate (C-S-H) as well as the crystalline ettringite and calcium hydroxide. The x-ray diffraction pattern of the hydrated cement is difficult to interpret because of its complexity. In addition, the overlapping lines from the remaining cement compounds make it difficult to quantify the amount of the crystalline components present. Using Rietveld analysis we have been able to interpret the patterns obtained from synchrotron x-ray diffraction patterns obtained at the Photon Factory at the Australian National Beamline Facility using BIGDIF. The changes in the composition of the hydrated cement paste were determined as a function of time during hydration at 60 deg C. © 2002 Australian X-ray Analytical Association Inc