Introduction to the concept of active rheology control in case of pumping of cementitious materials

In the framework of the European Research Council (ERC) Advanced Grant Project "Smartcast", new ways are fundamentally studied to develop the concept of Active Rheology Control (ARC) and Active Stiffening Control (ASC) of fresh concrete. Concrete pumping control is a major potential application of active rheology control (ARC) of concrete. Actve control of the yield stress of the pumped material will lead to a control of the pressure losses in the pumping pipe, both in steady state (dynamic yield stress) or while resuming pumping after a standstill (static yield stress). Active control of the rheological properties of the pumped material, by way of controlling the relation between shear rates and shear stresses, will lead to a control of velocity profiles and discharge rates. Active rheology control can be achieved, e.g. by applying static or alternating magnetic fields on concrete containing magnetic particles. The paper introduces the basic concept, and shows some elements of the experimental setup currently used as a proof of concept. An operational control of concrete pumping operations by applying adequate and well-positioned external fields along the pumping pipe is a realistic option.