Investigation of vibration on rheological behavior of fresh concrete using CFD-DEM coupling method

Vibration can increase the flow ability of fresh concrete and may cause segregation. The rheology behavior of fresh concrete after vibration is different from that in the unvibrated state. In this paper, a CFD-DEM coupling method was developed to investigate the rheological behavior of fresh concrete before and after vibration. The Bingham model and Hershcel-Bulkley were respectively used as the constitutive relationship of fresh concrete in unvibrated and vibrated state. The Hertz-Mindlin with bonding bond is employed to describe the interaction between coarse aggregate. To analyze the effect of vibration on the rheological behavior of fresh concrete, the rheometer test was conducted. The relationship of shear stress and shear strain rate is linear before vibration and is nonlinear after vibration. Vibration reduces the yield stress and plastic viscosity of concrete. The shear zone decreases when fresh concrete is vibrated.