Testing Pumpability of Concrete (2014-11)¶

To date, there are no standardized regulations for assessing the pumpability of fresh concrete in which the requirements for its rheological properties are specified. To test the pumpability of fresh concrete - especially on the construction site - the establishment of simple, robust and yet meaningful rheological measurement techniques is of fundamental importance. This article presents the new testing approaches for a reliable optimization of the pumping of fresh concrete. In particular, the mode of operation of the so-called sliding pipe rheometer (SLIPER) is explained, with which the flow rates, pressure conditions and resulting states of movement of the fresh concrete in a concrete delivery line can be quantitatively estimated in a good approximation. As part of a Pa - rameter study, the results obtained using SLIPER are analyzed and compared with those of a stationary concrete viscometer. The determined correlations between rheology and pumpability of both normal concretes and special concretes (self-compacting concrete (SCC) and high-ductility concrete (SHCC)) are presented. Finally, the predictive ability of the pumping behavior of concrete is validated on the basis of the SLIPER investigations by measuring the pumping pressure under construction site conditions.