Flow simulation of fresh concrete accounting for vibrating compaction

Abstract

Vibrating compaction is necessary for consolidating fresh concrete into form because it decreases inter-particle friction, which dramatically improves fluidity. Thus, vibrating compaction improves the workability and compactness of concrete and can even increase its density, strength, and durability. Nevertheless, the effect of vibrating compaction on the filling ability of normal concrete has rarely been discussed despite its importance. This paper introduces a numerical approach to estimating concrete-filling ability at vibration conditions. The vibration attenuation of a poker-type concrete vibrator is quantified using a vibration energy diffusion model, and the rheological behavior of fresh concrete under vibration is generalized. Then, volume-of-fluid (VoF) simulations taking into account the vibrating compaction are conducted to obtain the filling profiles. The simulation results provide a reasonable estimation, based on a comparison with the results of mock-up testing. The effects of attenuation coefficient, yield stress, and plastic viscosity on compacting efficiency are also discussed. In summary, the proposed method can estimate the filling of fresh concrete according to concrete rheology and attenuation of vibration.