Responsive superplasticizers for active rheology control of cementitious materials
Geert De Schutter, Metwally Ezzat, Karel Lesage, Richard Hoogenboom
Abstract
Actual concrete mixtures and casting processes do not enable on-demand real-time adjustment of the rheology of the fresh concrete, forcing operators to passively rely on the intrinsic evolution of the material properties during processing. Newly-developed functional polymers responsive to external electromagnetic trigger signals can be used as chemical admixtures in fresh cementitious materials to enable active rheology control (ARC) and active stiffening control (ASC) on demand. Polycarboxylate ether (PCE) based superplasticizers can be given extra functionalities by incorporating specific chemical groups. A TEMPO-based extension of PCE enables redox-controlled adsorption on cement particles, adjusting rheological properties. A DOPA-based extension of PCE in combination with magnetic nanoparticles enables magneto-rheological control. This paper presents the laboratory proof of concept results and opens a ground-breaking route for on-demand adjustment of rheology of fresh concrete in the post-mixing stage.