Simultaneous study of mechanical property development and early hydration chemistry in Portland cement slurries using X-ray diffraction and ultrasound reflection

Abstract A sample cell for the simultaneous measurement of synchrotron X-ray powder diffraction and ultrasound shear-wave reflection data from cement slurries is described. White cement slurries at 25 and 50 °C with 0–3% bwoc CaCl 2 were studied to illustrate the potential of the apparatus. The decrease in reflected S-wave amplitude, in dB, showed a linear correlation with C 3 S hydration. CaCl 2 retarded the development of G′ and G″ relative to the extent of C 3 S hydration. At short times, there was a correlation between the time evolution of both G′ and G″, and the amount of precipitated CH seen by diffraction, which was almost independent of CaCl 2 concentration and temperature. CaCl 2 addition resulted in a decrease in the amount of CH visible to X-rays, relative the degree of C 3 S hydration. This may indicate a change in C–S–H gel C:S ratio or the presence of nanoscale CH that could not be seen by diffraction.