Simulation of Concrete Pumped in Horizontal Coil and Super High-Rise Building Based on CFD

The Euler method of computational fluid dynamics (CFD), the Bingham constitutive relationship and the measured concrete performance indexes were combined as the basis, the horizontal coil test and super high-rise building pumping test of concrete were simulated by software FLUENT. The data of maximum pump pressure, pressure loss of horizontal pipe, pressure loss per horizontal bend, pressure loss of vertical pipe and pressure loss per vertical bend from the test and numerical model were analyzed comparatively. The results showed that the simulation models can promisingly describe the flow behavior of concrete during pumping. In addition, it was found that the thickness of the lubricating layer forming during the concrete flow in the pump pipe was about 2 mm. Finally, the velocity vector analysis of concrete flow in the pump pipe was elucidated. The velocity gradient of the lubrication layer decreased with the increase of the distance from the pump pipe inlet. The velocity gradient of the concrete in the yield layer raised continuously. The flow velocity of concrete in the plug layer boosted with the thickness of the plug layer abated gradually. The concrete tended to be stable after flowing about 6 m in the horizontal pipe.