Cracks play an essential role in the degradation of the thermomechanical behavior of ceramic matrix composites. However, characterizing their complex 3D geometries within a complex microstructure is still a challenge. This paper presents a series of procedures, based on X-ray tomographic images, to evaluate the applied 3D strains, including their t...
X-ray computed tomography (CT) is a non-destructive technique that offers a 3D insight into the microstructure of thick (opaque) samples with virtually no preliminary sample preparation. Since its first medical application in 1973, the technique has improved dramatically in terms of acquisition times and resolution. The best resolution achievable f...
X-ray diffraction (XRD) is a prominent technique to characterise cement-based materials. The combination of the Rietveld refinement with the Partial Or No Known Crystal Structure (PONKCS) approach now enables the quantification of both crystalline phases and amorphous contribution of SCMs. This paper describes the application of Rietveld-PONKCS to ...
X-ray diffraction (XRD) is a prominent technique to characterise cement-based materials. The combination of the Rietveld refinement with the Partial Or No Known Crystal Structure (PONKCS) approach now enables the quantification of both crystalline phases and amorphous contribution of SCMs. This paper describes the application of Rietveld-PONKCS to ...
For the last decades, new reparation or fabrication processes have been studied to replace traditional rebar by roving of different mineral or organic fibres to avoid corrosion issues. Such materials refer to the family of cementitious composite. Their tensile strength would directly depend on the proportion of reinforcement but also strongly on th...
The behavior of model granular materials (glass beads) wetted by a small quantity of liquid forming capillary bridges is studied by one-dimensional compression test combined with X-ray computed tomography (XRCT) observation. Special attention is paid to obtain very loose initial states (initial void ratio of about 2.30) stabilized by capillary cohe...
This paper studies the thermal effects on the mineralogical properties as well as the microstructure of 5 year-aged cement pastes, unprotected from contact with the air, heated up to various temperature up to 1000 °C in steps of 100 °C for a constant period of 6 h by studying the TGA/DTG and XRD curves. In order to simulate a real situation of a fi...
In this paper, we introduce a new technique based on X-ray radiography with high temporal (O(0.1 s)) and spatial (O(10 μm)) resolutions to study fast suspension flows regardless of optical access. We benefit from the axial symmetry of our flow configuration, a wide gap Couette setup, to extract a 3D solid volume fraction field from a single X-ray p...
In the conventional French railway substructures, a layer namely interlayer was created naturally by the interpenetration of ballast and subgrade. The lower part of this interlayer is characterized by a matrix of fines with inclusion of coarse grains in it. Moreover, the coarse-grain content is decreasing over depth. In this study, the effect of vo...
