Abstract
A numerical model accounting for the effects of neutron irradiation on concrete at the mesoscale is detailed in this paper.
Irradiation experiments in test reactors [Elleuch 1972], i.e., in accelerated conditions, are simulated.
Concrete is considered as a two-phase material made of elastic inclusions (aggregate) subjected to thermal and irradiation-induced swelling and embedded in a cementitious matrix subjected to shrinkage and thermal expansion.
The role of the hardened cement paste in the post-peak regime (transition brittle-ductile with decreasing loading rate), and creep effects are investigated.
Radiation-induced volumetric expansion (RIVE) of serpentine aggregate cause the development and propagation of damage around the aggregate which further develops in bridging cracks across the hardened cement paste between the individual aggregate particles.
The development of damage is aggravated when shrinkage occurs simultaneously with RIVE during the irradiation experiment.
The post-irradiation expansion derived from the simulation is well correlated with the experimental data and, the obtained damage levels are fully consistant with previous estimations based on a micromechanical interpretation of the experimental post-irradiation elastic properties [Le Pape 2015].
The proposed modeling opens new perpectives for the interpretation of test reactor experiments in regards to the actual operation of light water reactors.
