Exploration of the X-ray Dark-Field Signal in Mineral Building Materials

Abstract

Mineral building materials suffer from weathering processes such as salt efflorescence, freeze–thaw cycling, and microbial colonization. All of these processes are linked to water (liquid and vapor) in the pore space. The degree of damage following these processes is heavily influenced by pore space properties such as porosity, pore size distribution, and pore connectivity. X-ray computed micro-tomography (µCT) has proven to be a valuable tool to non-destructively investigate the pore space of stone samples in 3D. However, a trade-off between the resolution and field-of-view often impedes reliable conclusions on the material’s properties. X-ray dark-field imaging (DFI) is based on the scattering of X-rays by sub-voxel-sized features, and as such, provides information on the sample complementary to that obtained using conventional µCT. In this manuscript, we apply X-ray dark-field tomography for the first time on four mineral building materials (quartzite, fired clay brick, fired clay roof tile, and carbonated mineral building material), and investigate which information the dark-field signal entails on the sub-resolution space of the sample. Dark-field tomography at multiple length scale sensitivities was performed at the TOMCAT beamline of the Swiss Light Source (Villigen, Switzerland) using a Talbot grating interferometer. The complementary information of the dark-field modality is most clear in the fired clay brick and roof tile; quartz grains that are almost indistinguishable in the conventional µCT scan are clearly visible in the dark-field owing to their low dark-field signal (homogenous sub-voxel structure), whereas the microporous bulk mass has a high dark-field signal. Large (resolved) pores on the other hand, which are clearly visible in the absorption dataset, are almost invisible in the dark-field modality because they are overprinted with dark-field signal originating from the bulk mass. The experiments also showed how the dark-field signal from a feature depends on the length scale sensitivity, which is set by moving the sample with respect to the grating interferometer.

Mix and measure II: joint high-energy laboratory powder diffraction and microtomography for cement hydration studies

“…This work uses absorption-based X-ray imaging, but X-ray grating-based imaging could help in the characterization of sub-resolution features. The implementation of these approaches is being extended from synchrotron beamlines to laboratory instruments (Prade et al, 2016;Blykers et al, 2022). X-ray diffraction/scattering computed tomography is also being extended to laboratory equipment (Cersoy et al, 2015).…”

“…(iii) The DoH for C 4 AF is 60-70% at 28 d. These values are a bit lower than those reported previously, 70 and 90% by Lothenbach et al (2008) and Noguchi et al (2021), respectively. C 4 AF reactivity varies significantly depending upon the melt composition and the clinkering thermal history (Peys et al, 2022;Boha ´c ˇet al, 2024). It has been reported very recently that the C 4 AF hydration rate can be strongly enhanced by the additional surfaces of the SCMs (Redondo-Soto et al, 2023;Morales-Cantero et al, 2024) and accelerating admixtures (Peys et al, 2022;Chang et al, 2024) that can be present in the grinding agents.…”

Experimental Study on the Microfabrication and Mechanical Properties of Freeze–Thaw Fractured Sandstone under Cyclic Loading and Unloading Effects

“…It is a method of inspecting the interior deterioration of materials. Benjamin K. Blykers scanned mineral building materials using X-ray dark-field imaging (DFI) to analyze the micropores inside the materials through dark-field signals [11]. CT technology is increasingly being utilized to examine the interior damage features of rocks.…”

Implementation of a dual-phase grating interferometer for multi-scale characterization of building materials by tunable dark-field imaging

“…In building material characterization, i.e. to reach high sensitivity to features up to hundreds of nanometers the FOV goes down to the micrometer scale 9 , 10 .…”

“…Previous studies using GI in synchrotron facilities have shown that DF is able to differentiate between two different nanoscale pore sizes 13 , and two materials in bricks with a sub-pixel resolution 10 . Different TL-XGI setups have been implemented and optimized for the phase contrast of biomaterials 14 .…”