Quantification of carbonated Mg-based cement pastes by Raman spectroscopy

This study presented a detailed investigation of the carbonation of reactive magnesia cement (RMC) and brucite cement by using Raman spectroscopy and other characterization techniques. Quantification of carbonation at different depths and formation of various reaction products in each system were demonstrated. Correlations between Raman peak intensities and carbonation degree were established by Raman mapping. Established correlations were employed to evaluate the carbonation behaviour of RMC and brucite cement. Results indicated the higher sensitivity of Raman spectroscopy than XRD in detecting different carbonation products at early stages. This information can be used to assess the strength and microstructural development of RMC and brucite cement since different HMCs have distinct properties and performance contributions, and their transformation plays a key role in microstructural and strength development. This study provided further understanding of the carbonation mechanisms of Mg-based systems, which could enable carbonation degree and performance prediction via the established correlations.