Developing a Discrete Element Model for simulating fresh concrete: Experimental investigation and modelling of interactions between discrete aggregate particles with fine mortar between them

The article at hand presents an investigation with the objective of developing of a material model for adequate simulation of the rheological behaviour of fresh concrete using the Discrete Element Method (DEM). The methodology for investigation of the interaction between neighbouring particles with some amount of viscoelastic material between them is explained. The experimental investigations were performed with various materials: polymer solutions in water (material with time-independent rheological behaviour) and two types of fresh mortar (with time-dependent rheological behaviours). Characteristic material behaviours for various loading regimes are presented and critically discussed. On the basis of the experimentally obtained force-displacement relations a material model for interaction of neighbouring solid particles in normal direction is developed. This model can be directly introduced in codes based on the Distinct Element Method.