Print Email Facebook Twitter The Effect of Viscosity-Modifying Admixture on the Extrudability of Limestone and Calcined Clay-Based Cementitious Material for Extrusion-Based 3D Concrete Printing Title The Effect of Viscosity-Modifying Admixture on the Extrudability of Limestone and Calcined Clay-Based Cementitious Material for Extrusion-Based 3D Concrete Printing Author Chen, Y. (TU Delft Materials and Environment) Chaves Figueiredo, S. (TU Delft Materials and Environment) Yalçinkaya, Ç. (TU Delft Materials and Environment; Dokuz Eylul University) Copuroglu, Oguzhan (TU Delft Materials and Environment) Veer, F.A. (TU Delft Structural Design & Mechanics) Schlangen, E. (TU Delft Materials and Environment) Date 2019 Abstract To investigate the effects of viscosity-modifying admixture (VMA) on the extrudability of limestone and calcined clay-based cementitious materials, three mix designs with different dosages of VMA were proposed in this study. The ram extrusion was utilized as an extrusion model for exploring the fresh properties of printable materials. Two methods were used, based on the ram extruder setup—(a) extruding materials with the same extrusion speed at different rest times to determine how the pressure changes with time; (b) extruding materials with different extrusion speeds at the same rest time to investigate the material flow parameters using the Basterfield et al. model. The main findings of this study could be summarized as—(1) the extrusion pressure of all mix designs exhibited an increasing trend with time. At the same tested age, the extrusion pressure under 0.25 mm/s of piston speed was increased and the shape retention of the extruded filaments was enhanced by increasing the dosage of VMA; (2) the correlation between the experimental results and the Basterfield et al. model was excellent (R-squared value: 0.99). The mixture with a higher content of VMA showed an increased elongational yield stress, flow consistency, and shear yield stress. Subject ExtrudabilityExtrusion-based 3D concrete printingLimestone and calcined clayRam extruderViscosity-modifying admixture To reference this document use: http://resolver.tudelft.nl/uuid:3c4c4a0b-449d-47e2-a7c2-e9fdf2172051 DOI https://doi.org/10.3390/ma12091374 ISSN 1996-1944 Source Materials, 12 (9) Part of collection Institutional Repository Document type journal article Rights © 2019 Y. Chen, S. Chaves Figueiredo, Ç. Yalçinkaya, Oguzhan Copuroglu, F.A. Veer, E. Schlangen Files PDF materials_12_01374.pdf 4.24 MB Close viewer /islandora/object/uuid:3c4c4a0b-449d-47e2-a7c2-e9fdf2172051/datastream/OBJ/view