Preliminarily experimental research on local pressure loss of fresh concrete during pumping

The pressure of the fresh concrete during pumping in conveying pipes is critical in both concrete pump design and conveying pipes layout. The local pressure loss occurring at the connections between pipes, which often has been overlooked in the total pumping pressure research, is quite significant compared to the total pressure drop, especially for long conveying pipes. In this study, strain gauge based method was applied to measure the pressure drop at the connections of concrete during pumping. In this method, the strain gauges were calibrated by water pressure to obtain the correlation between the strain and pressure. An empirical equation for predicting the local pressure loss was also proposed and validated based on the experimental data. The results indicated that the pressure loss per pipe connection for general grades of concrete is within 0.01–0.045 MPa when the pumping rate ranges from 40  to 80  m³/h to 80 m³/h.