Recent studies of cements and concretes by synchrotron radiation crystallographic and cognate methods

Abstract

The portfolio of available synchrotron radiation techniques is increasing notably for cements and pastes. Furthermore, sometimes the terminology is confusing and an overall picture highlighting similarities and differences of related techniques was lacking. Therefore, the main objective of this work is to review recent advances in synchrotron techniques providing a comprehensive overview. This work is not intended to gather all publications in cement chemistry but to give a unified picture through selected examples. Crystallographic techniques are used for structure determination, quantitative phase analyses and microstructure characterization. These studies are not only carried out in standard conditions but synchrotron techniques are especially suited to non-ambient conditions: high temperatures and pressures, hydration, etc., and combinations. Related crystallographic techniques, like Pair Distribution Function, are being used for the analysis of ill-crystalline phase(s). Furthermore, crystallographic tools are also employed in imaging techniques including scanning diffraction microscopy and tomography and coherent diffraction imaging. Other synchrotron techniques are also reviewed including X-rays absorption spectroscopy for local structure and speciation characterizations; small angle X-ray scattering for microstructure analysis and several imaging techniques for microstructure quantification: full-field soft and hard X-ray nano-tomographies; scanning infrared spectro-microscopy; scanning transmission and fluorescence X-ray tomographies. Finally, a personal outlook is provided.