Overview and remaining challenges of active rheology control of cementitious materials

During processing and casting, the workability of concrete can be a challenging issue due to lack of robustness of the mixture or because of contradictory requirements during different processing steps (e.g. pumping and formwork casting). With current methodologies, no real options are available after mixing to further adjust the workability of the concrete during processing. A new and groundbreaking technology has been developed recently at Ghent University, Belgium, enabling active rheology control, including active stiffening control. This can be achieved in two ways. A first route consists of adding magnetizable solid particles to the concrete responding to an external magnetic field. A second and highly innovative route consists of applying switchable superplasticizers that can be triggered by an external signal (e.g. electric or magnetic). While the laboratory proof of concept has been obtained at paste level, further upscaling and valorization studies are ongoing.