Modelling of concrete behaviour in uniaxial compression and tension with DEM

The paper focuses on the DEM modelling of the behaviour of plain concrete during uniaxial compression and uniaxial tension using the discrete element method. The model takes into account the concrete heterogeneity at the meso-scale level. The effects of concrete density, size of aggregate grains and specimen size on the stress–strain curve, volume changes and fracture process are studied. In addition, the evolution of contact forces, grain rotations, displacement fluctuations and strain localization during deformation is investigated. The elastic, kinetic, plastic and numerical dissipated energy is calculated and analysed at a different stress–strain stage. Concrete is described as a 1-phase or 3-phase material. The macroscopic 2D and 3D results are compared with the corresponding experiments. A satisfactory agreement between experiments and calculations is achieved.