Workability of concrete varies during pumping. Even though concrete satisfies the required workability before pumping, it often does not satisfy the required standard after pumping. Moreover, serious problem could happen such as segregation and blockage. In this study, the rheological properties of concrete change during pumping from the pressure distribution over the pipe length was investigated. The rheological properties and the pressures measured from seven different real-scale pumping tests with 116 m to 1000 m long pipelines and 24 MPa to 100 MPa concrete were analyzed. As a result, it was found that the rheological properties vary gradually along the pipeline, and could abruptly change inside the pump. The variation of rheological properties during pumping seems to be attributed in part to the increase of water absorption in aggregates under high pressure and the additional mixing effect, namely, intensive shearing under high pressure inside pump.

中文翻译：

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混凝土泵送过程流变性能变化的实验观察

泵送过程中混凝土的和易性会发生变化。尽管混凝土在泵送前满足了要求的和易性，但泵送后往往达不到要求的标准。此外，可能会发生严重的问题，例如离析和堵塞。在这项研究中，研究了泵送过程中混凝土的流变特性从管道长度上的压力分布变化。对 116 m 至 1000 m 长管道和 24 MPa 至 100 MPa 混凝土的七种不同实际泵送试验测量的流变特性和压力进行了分析。结果发现，流变特性沿管道逐渐变化，并可能在泵内部突然变化。