A Discrete Element Model For The Fracture Analysis of Reinforced Concrete

The Discrete Element Method was initially applied to the analysis of discontinuous media, e.g. in rock mechanics and soil mechanics. Recently the DEM has been used in fracture studies of non-homogeneous continuous media such as concrete and rock. A 2D circular rigid discrete element formulation based on the DEM that has been further developed to model concrete is adopted [

1

].

To simulate the concrete at the meso-level, random assemblies of particles based on a given sieve analysis have to be generated. The DEM model micro-properties also have to be previously calibrated through uniaxial tension and compression tests. The formulation of a 1D rigid discrete element that interacts with the discrete rigid particles through contact interfaces is presented.

The DEM enhanced model with reinforcement capabilities is evaluated in a three point bending [

2

] and in a four point bending [

3

] tests experiments of reinforced concrete beams without stirrups. Under flexure loading conditions the model is shown to predict the expected final crack pattern, the crack propagation and the load displacement diagram. Under shear loading conditions the model is shown to predict the size effect behaviour that occurs on beams without stirrups failing under diagonal shear and also the expected crack propagation and final crack patterns.