Since the early 20th century, the necessity of modeling and monitoring fresh concrete behavior has been recognized by the industry with the objective to ensure adequate mechanical properties and a proper durability of concrete structures. Due to the rapid development of computer technology, the applications of computational simulation tools in the field of concrete technology has significantly increased and help us to understand the mechanisms of rheological systems. The development of proper rheological models and suitable numerical methods are considered as basic needs for a thorough understanding of the flow properties. The main challenge is finding a quantitative correlation between the model parameters and the properties and proportions of the mix ingredients. This paper presents a numerical approach for macroscopic behavior of a fresh self-compacting mixture using Discrete Element Method (DEM). The employed research is based on a conceptual idea where the grain-paste interaction is explicitly modelled as an interactive two-phase system. Each mixture is considered to be an assembly of “grain-paste” systems, which can be characterized according to the mix composition based on the “excess paste theory”. The macroscopic behavior is evaluated based on the slump flow test results. Simulations and experimental laboratory test results show good agreement.