During concrete pumping, a lubrication layer is formed at the interface between the concrete and the pipe. The pumpability depends strong- ly on the characteristics of this layer. In this paper, a method to enhance the pumpability by externally imposing an electromagnetic field on the pipe was introduced and verified experimentally. The electromagnetic field activates the free movement of the water molecules so that the layer is expected to become slipperier. Pumping tests with a 1,000 m long pipeline were conducted with concrete. When the electro- magnetic field was imposed, the same discharge rate could be obtained with a 30% reduction in pump pressure, and a 15% increase in the velocity under the same pump pressure was observed. The tests showed that the application of an electromagnetic field was quite effective in improving the pumpability of concrete.
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