  The present parametric study deals with the meso-scale modelling of concrete
subjected to cyclic compression, which exhibits hysteresis loops during
unloading and reloading. Concrete is idealised as a two-dimensional three-phase
composite made of aggregates, mortar and interfacial transition zones (ITZs).
The meso-scale modelling approach relies on the hypothesis that the hysteresis
loops are caused by localised permanent displacements, which result in
nonlinear fracture processes during unloading and reloading. A parametric study
is carried out to investigate how aggregate density and size, amount of
permanent displacements in the ITZ and the mortar, and the ITZ strength
influence the hysteresis loops obtained with the meso-scale modelling approach.
