Abstract
When concrete is being pumped through a pipe, a lubrication layer is formed at the interface between the concrete and pipe, which plays a dominant role in determining the pumpability. In the present study, a method to improve the properties of the lubrication layer was suggested by imposing ultrasound on the pipe. To examine the effects of ultrasound on the formation of lubrication layer, three different intensities of ultrasonic energy were applied while conducting 170 m long full scale pumping tests. When ultrasound was applied, the lubrication layer thickness increased, which led to a decrease in pumping pressure. Therefore, the application of ultrasound can be an effective method for improving pumpability.
