PhD Defense | Abdo Shamseldin | Evolution of the Chemo-Hygro-Mechanical Properties of Tunnel Lining Concrete Exposed to Different Temperatures and Relative Humidities

Evolution of the Chemo-Hygro-Mechanical Properties of Tunnel Lining Concrete Exposed to Different Temperatures and Relative Humidities.

As nuclear energy continues to play a vital role in global power generation, it becomes increasingly critical to understand the long-term performance of concrete in nuclear infrastructure. This Ph.D. thesis examines the behavior of high-strength concrete in two important nuclear applications: geological disposal facilities (GDFs) for radioactive waste and nuclear power plant (NPP) containment structures. Focusing on Belgium’s reference design for deep geological disposal in clay formations, the study examines the effects of elevated temperatures (up to 85 °C) on the mechanical, chemical, and moisture-related properties of concrete over time. The research centers on a ternary blended cement system that incorporates silica fume and blast furnace slag, which introduces complex hydration and microstructural changes under thermal stress. Through a rigorous experimental program, the thesis examines concrete aging at ambient and elevated temperatures, evaluates time-dependent deformations such as creep and shrinkage, and assesses the predictive accuracy of the Fib Model Code 2020 (MC-2020). The results offer valuable insights into the durability and stability of concrete in thermally demanding nuclear environments, contributing to safer and more resilient waste containment and reactor infrastructure.

Promoters:

• Roman Wan-Wendner (UGENT)

SCK CEN mentors:

• Suresh Seetharam
• Quoc Tri Phung