PhD fellowship : Characterization and modelling of cement pastes with alternative supplementary cementitious materials (ASCMs): chemo-mechanical properties of heterogeneous microstructures

PhD fellowship in the framework of a FQRNT-funded research collaboration between
Université Laval, Université de Sherbrooke, ÉTS, EMPA and Northwestern University

Characterization and modelling of cement pastes with alternative supplementary cementitious materials (ASCMs): chemo-mechanical properties of heterogeneous microstructures

In the context of climate changes, a contemporary challenge for concrete scientists is to develop and foster the industrial implementation of eco-friendly alternative supplementary cementitious materials (ASCMs). More specifically, these ASCMs impacts the microstructure of cement pastes, influencing the composition of phases and their long-term properties. Building on previous work characterizing chemo-mechanical properties of microstructure phases (Wilson et al. 2018), this work aims at improving the understanding of alternative systems including silica-rich SCMs (e.g. glass powder, magnesium extraction residue; C-(A)-S-H with low Ca/Si) and alumina-rich SCMs (e.g. metakaolin; C-(A)-S-H with low Ca/[Si+Al])
In this project, the goal of the PhD student will be to comprehensively characterize these systems at the micron scale in terms of chemistry, microstructure and mechanical properties. This will be achieved by a combination of experimental and modelling approaches. In addition to the physico-chemical analyses of the raw materials and hydrated cement pastes (using XRF, XRD, TGA, NMR), the chemo-mechanical properties of the microstructure phases will be investigated using the cutting-edge coupling of nanoindentation and quantitative EDS chemical analyses (NI-QEDS). In parallel, the evolution of phase assemblage over time will be modelled using a thermodynamics approach, in collaboration with Dr. Frank Winnefeld at the Swiss Federal Laboratories for Materials Science and Technology (EMPA). This experimental work will be performed under the supervision of Professor Arezki Tagnit-Hamou, mainly at the Université de Sherbrooke and at the Université Laval (Québec). Moreover, the student will be codirected by Prof. Sorelli of Université Laval and Prof. Ouellet-Plamondon of ÉTS, Montreal.
Furthermore, the PhD student will work in collaboration with a PhD second student whom mission will be to develop numerical models to upscale from micro-to-macro the mechanical properties of the investigated systems. Finally, the work will be performed in collaboration with the other experts involved in the project: Dr William Wilson (UdS) et Dr. Frank Winnefeld (EMPA).
Duration : 3-4 years
Salary : About 18’500$/year (net of tax) plus 3‐5000$ bonus/year