Numerical simulation of the casting process of steel fiber reinforced self-compacting concrete: Influence of material and casting parameters on fiber orientation and distribution

The orientation and distribution of fibers immersed in the self-compacting concrete (SCC) are affected by various material and casting parameters, and knowledge of the variation of fiber orientation is important for improving the mechanical properties of steel fiber reinforced self-compacting concrete. Therefore, a computational fluid dynamics (CFD) based method that can monitor the fiber orientation and distribution during concrete flow is developed in this work. In this method, the flow of fresh concrete and the movement of fibers are calculated by a CFD software (ANSYS CFX) and MATLAB code respectively. Through comparisons with the results in two experiments, the accuracy of this method was verified. Furthermore, the influence of rheological properties of fresh concrete, casting point location, formwork height, formwork width and formwork length on the variation of the fiber orientation and distribution was investigated. The numerical results regarding concrete flow state, fiber distribution state, probability density distribution of fiber orientation, average fiber orientation angle, the change of fiber orientation with the casting time, and fiber distribution along the length of the beam were analyzed, which can provide a reference for optimizing the casting process and mechanical performance of steel fiber reinforced self-compacting concrete (SFRSCC). Among these material and casting parameters, formwork length was shown to be the most significant parameter affecting fiber orientation and distribution during the flow of steel fiber reinforced self-compacting concrete.