Rebar corrosion is one of the main causes of premature degradation of concrete infrastructures, including in the nuclear sector, where concrete is extensively used in containment structures and waste storage facilities. Carbonation, caused by the penetration of CO2 into the concrete, lowers the pH of the pore solution, promoting rebar corrosion. This corrosion leads to the formation of expansive products that can cause cracking in the material. The proposed thesis work, developed as part of a European collaborative project between CEA Saclay, École des Mines de Paris - PSL, and IRSN, aims to develop a numerical model to simulate these phenomena. The model combines a reactive transport code (Hytec) and a finite element code (Cast3M) to study the local effects of carbonation-induced corrosion on concrete cracking. This project will benefit from parallel experimental work to gather data for parameter identification and model validation. The first part of the research will focus on modeling the carbonation of cementitious materials under unsaturated conditions, while the second part will address the corrosion of rebar caused by the pH drop induced by carbonation. The model will describe the growth of corrosion products and their expansion, inducing stress within the concrete and potential microcracking.
This research project is aimed at a PhD student wishing to develop their skills in materials science, with a strong focus on multi-physical and multi-scale modeling and numerical simulations. The thesis will be carried out principally at CEA Saclay and at École des Mines de Paris – PSL (Fontainebleau).