A multiscale approach to model early age thermo-hydro-mechanical behaviour of non-reinforced concrete.

The integrity of non-reinforced concrete structures at early stages of construction depends on many factors. One of these is the formation of cracks, which may be crucial in some applications. This problem is of great relevance for deep geological disposal concepts which consider concrete as one of the principle engineered barrier components, and for which the expected service life is > 1000s of years. This is particularly the case within the current Belgian disposal concept in which heat emitting radioactive wastes are post-conditioned in concrete/steel containers, to be placed in a deep underground geological formation using a system of galleries supported by non-reinforced concrete lining. In the early stages of repository construction and waste emplacement, the mechanical integrity of the concrete components is of utmost importance from the point of view of safety and performance. The potential retrievability/reversibility of wastes within a prolonged time period after waste emplacement places additional performance requirements on these concrete structures, which must retain their structural integrity over this period. The principal objective of this PhD is to make a first attempt at developing and implementing a multiscale-based coupled thermo-hydro-mechanical model to study the early age behaviour of nonreinforced concrete. In particular, the PhD student will develop a mathematical model that captures cracking potential due to thermo-hydraulic-mechanical transient conditions. To a limited extent, a secondary objective is also envisaged in which small laboratory-scale experiments may be carried out to derive parameters of importance for the multiscale models as well as for validation purposes.

Keywords:ENGINEERING

Disciplines:Thermodynamics

Project type:Collaboration project