3D Visualization of mineral carbonation : μCT as a tool to understand pore scale processes

A material can only be considered as a waste if it has no economic value. Transforming waste products, that would normally end up in landfills, into raw materials and products that have economic value is one of the main goals in a zero waste mindset and one of the possibilities to ensure a sustainable future. This thesis focuses on a valorization route for steel slag and CO2, two substances which are generally considered as waste products. When a compact of fine grained steel slag grains is exposed to pressurized CO2, a carbonation reaction is triggered, which binds the grains together and allows to generate building blocks with a high compressive strength. The reactions associated with the carbonation process are an interplay between CO2, water and minerals and take place in the pore space of the steel slag compact. The main focus of this work is to analyse the carbonatio

Motion compensated micro-CT reconstruction for in-situ analysis of dynamic processes

This work presents a framework to exploit the synergy between Digital Volume Correlation ( DVC) and iterative CT reconstruction to enhance the quality of high-resolution dynamic X-ray CT (4D-mu CT) and obtain quantitative results from the acquired dataset in the form of 3D strain maps which can be directly correlated to the material properties. Furthermore, we show that the developed framework is capable of strongly reducing motion artifacts even in a dataset containing a single 360 degrees rotation

Dynamic micro-CT analysis of fracture formation in rock specimens subjected to multi-phase fluid flow

In this study, fracture formation in rocks is being studied at the pore-scale through the combination of high-resolution X-ray CT scanning with custom-made add-on modules. The Deben CT5000 system, an in-situ load cell, was used at the scanners at the Centre for X-ray Tomography at Ghent University (UGCT), providing information on mechanical properties of the tested rocks. Micro-CT scans made at the High Energy CT system Optimised for Research (HECTOR) allowed the visualisation of the fracturesk and their formation as well as the analysis of porosity changes in the material, related to the changes in stress

Pore-scale characterization and modelling of CO2 flow in tight sandstones using X-ray micro-CT; Knorringfjellet formation of the Longyearbyen CO2 lab, Svalbard

Rocks of the Knorringfjellet Formation in Central Spitsbergen form a potential storage reservoir for CO2 below Longyearbyen. They are characterised by a moderate porosity and low permeability. However, water injection tests have shown positive results and fractures are considered to facilitate fluid flow. Therefore, hard data on fracture parameters and pore characteristics schould be analysed to better understand flow characteristics. Consequently, sandstone and conglomerate samples from the Knorringfjellet Formation were sampled and characterised with High Resolution X-ray Computed Tomography (HRXCT) at the Centre for X-ray Tomography at Ghent University, Belgium (UGCT). The dataset includes samples taken from drillholes in the vicinity of Longyearbyen, drilled during the pilot phase at the Longyearbyen CO2 project, as well as from the Knorringfjellet Formation outcrops at Konusdalen and Criocerasdalen. This was done in order to compare micro-fracture and pore parameters in both settings. With HRXCT, the samples were analysed at pore scale and quantitative information of the pore network and fractures were extracted. Pore networks were used for the modelling of CO2 flow in specific samples and information on fracture aperture was obtained at a micrometre scale. The acquired dataset can be directly used for a better understanding of flow in the aquifer

On how X-ray (micro) computed tomography on turbidites can help us unravel paleoflow successions, directions and dynamics

C

Chemo-mechanics of salt and ice crystallization in rocks : a 4D study using X-ray micro computed tomography

COMInternational audienc

Contributions of X-ray CT to the characterization of natural building stones and their disintegration

This paper highlights the use of the high resolution scanner at the Centre for X-ray Tomography in Ghent, Belgium (UGCT), for the 3D quantitative evaluation of the disintegration of some French natural building stones. Rocks deteriorate when they are exposed to extreme weathering factors such as a combination of water and freeze-thaw cycles or high pressure. The results of those processes can be very diverse: from element migration to crust formation to the origination of micro-cracks. Thanks to its non-destructive character, high resolution computed tomography (CT) turned out to be an excellent monitoring tool as it contributes to the characterization of the internal structure of the natural building stone. X-ray CT also provides a better insight into the micro-structural durability properties of the building stone

Investigating the influence of dynamic effects on two-phase flow at the pore scale with fast laboratory-based X-ray micro-CT

C