Quantitative mineralogical mapping of hydrated low pH concrete

Concrete materials are made of various minerals and phases, whose spatial heterogeneous distributions impact the overall physical and chemical properties of the materials. We have investigated the heterogeneous distribution of minerals and phases in two types of concrete using quantitative X-ray intensity maps coupled with an innovative data treatment method based on image segmentation. This method provided quantitative data on spatial distribution, modal content and associated calculated formulas for each identified mineral and phase in the binder with micrometer resolution. We also obtained quantitative information on the porosity associated with the phases, making it possible to differentiate poorly hydrated cement phases (initial clinker hydration reaction) from highly hydrated phases (final cement product) despite their similar chemical composition, when expressed in terms of cationic formulas. We quantified the mineralogical and phase contents, independent of crystal size or crystallinity considerations. We report spatial resolution in the pozzolan hydration process over different observation scales for the two investigated concretes.