Raman spectroscopy for the analysis of cements – past, present and future

Until recently there has been a common held misconception that Raman spectroscopy of cements is not possible, or at least so inconvenient as to make it impracticable. However, whilst not a routine analysis method Raman analysis of cementitious materials is possible, provided that suitable consideration is given to the technique’s limitations. This paper will chart the history of Raman spectroscopy applied to cementitious systems, review recent developments in the field and look towards possible future developments. Raman spectroscopy is a vibrational spectroscopic technique often considered complementary to infra-red spectroscopy, and provides information on the short-range order and local bonding in materials. Furthermore, the common coupling of a spectrometer to an optical microscope enables spatial resolution in the order of microns, whilst the rapid analysis times and low sensitivity towards water enables in-situ analysis of hydrating pastes. Furthermore, the technique is particularly sensitive to sulphate and carbonate environments, and is semi-quantitative.