Discrete-element modelling of concrete behaviour under uniaxial compressive test

Abstract

This paper presents a three-dimensional (3D) simulation of the concrete behaviour in a uniaxial compressive test using discrete-element modelling (DEM). The aim of this paper is to validate the numerical model developed and to study the cracking initiation and failure process in order to better understand the fracture behaviour of concrete. The particles were distributed using an algorithm that is based on sieve test analysis. The parameters were set up in order to validate the numerical model with the experimental result. It was observed that the 3D model is in line with the laboratory test in term of stress-strain response and macroscopic cracks development. Once the bond between the spheres was broken, it led to the formation of microscopic cracks, which were not visible in laboratory tests. From the observation recorded during the testing, it is clear that DEM is capable of capturing concrete behaviour both quantitatively and qualitatively. At the yielding point in the concrete the strain energy is released in the form of kinetic energy, frictional slip energy, energy of dashpot and local damping. Hence, it can be concluded that DEM can be used to study the random nature of the cracking and fracturing of concrete structures.