Enhancing Printable Concrete Thixotropy by High Shear Mixing

Aileen Vandenberg (1) , Hela Bessaies Bey (2) , Kay Wille (1) , Nicolas Roussel (3)

1 UCONN - University of Connecticut
2 IFSTTAR/MAST/CPDM - Comportement Physico-chimique et Durabilité des Matériaux
3 navier umr 8205 - Laboratoire Navier

Our results show that the storage elastic modulus as a function of time increases at a higher rate for the cement paste mixed at higher versus lower mixing intensiy. Hence, higher mixing appears to be enhancing thixotropy. Using calorimetry analysis we find that higher mixing decreases the setting time and enhances the peak of the heat flow. By analyzing the nanoparticles present in the suspending fluid of the cement paste, we show, in accordance with literature, that an appropriate combination of mixing energy and superplasticizer dosage promotes hydration by scratching hydrates from the surface of cement particles, stabilizing them in the suspending fluid and hence generating additional nucleation surfaces. These results open the door for the design of printing heads including high-shear micro mixers allowing for a faster liquid-to-solid transition of the printable material.

Mots clés: THIXOTROPY; NANOPARTICLES; MIXING; CALORIMETRY; DLS

Mots clés: THIXOTROPIE; NANOTECHNOLOGIE; PATE DE CIMENT; FLUIDE

Domaines: Milieux fluides et réactifs

Aileen Vandenberg, Hela Bessaies Bey, Kay Wille, Nicolas Roussel. Enhancing Printable Concrete Thixotropy by High Shear Mixing. Digital Concrete '18 : First Rilem International Conference on Concrete and Digital Fabrication, Sep 2018, ZURICH, Switzerland. pp. 94-101, ⟨10.1007/978-3-319-99519-9_9⟩. ⟨hal-01913688v2⟩