Fig. 2: In situ multicontrast X-ray tomographic studies of cement hydration.

a Selected orthoslices for the three imaging approaches. (Top) Attenuation-contrast laboratory data (Lab-μCT) for a PC-52.5 paste with w/c = 0.40. (Middle) Inline propagation-based phase-contrast synchrotron data (Syn-μCT) for a PC-42.5 paste with w/c = 0.50 [phases retrieved by using the Paganin algorithm⁵¹], (bottom) Quantitative phase-contrast, phases retrieved by near-field PXCT for a PC-52.5 paste scanning a region with w/c∼0.40. The thicknesses of the capillaries are given. b Enlarged views for the three approaches, at the three hydration ages, to qualitatively illustrate the quality of the data (contrast and spatial resolution). Clinker minerals are seen as whitish particles, porosity as darkish regions, and hydrates have intermediate grey tones. c Histograms for the different tomographic studies and hydration times. The histograms were obtained by computing the largest possible volumes without including the glass capillary walls.