New insights in weathering analysis of anhydrous cements by using high spectral and spatial resolution Confocal Raman Microscopy

Abstract

Raman spectroscopy when is combined with Confocal microscopy is a non-destructive technique that allow us to obtain information in cementitious materials. In this study, we present non-destructive image and structural analysis of anhydrous cements with carbonation evidences by Confocal Raman Microscopy (CRM). The results obtained by CRM have been corroborated by the techniques commonly used for this purpose as FTIR and DTA/TG. CRM shown the presence and distribution of the main phases present in cement (C2S and C3S) including those related with weathering (CaCO3 and sulphates). The results obtained by CRM show a direct relationship between the presence of the weathering processes of an anhydrous cement with the presence of sulphates and surprisingly, with the existence of amorphous carbon in the medium.