A discrete element model of concrete under high triaxial loading

A numerical model based on a three dimensional Discrete Element Method (DEM) has been used to study the behavior of concrete under high-confining pressures (up to 650 MPa). At this range of pressures, irreversible compaction of the material occurs and needs to be considered. Within the discontinuous nature of the model, a local constitutive law has been developed to reproduce this phenomenon quantitatively. Local parameters to be used in this constitutive law are identified by simulating reference uniaxial and triaxial experimental tests in compression. Once these parameters have been obtained, the model is used to predict the response of concrete sample for triaxial compressive tests at different levels of confinement. Beyond the macroscopic volumetric and stress–strain response, the model gives interesting insights on the local evolution of the nature of the interaction forces between the discrete elements. The computational implementation has been carried out in the discrete element and open source code YADE (http://yade-dem.org[20]).