Properties of 3D Printable Concrete

• Main Authors: Van Zijl, Gideon P. A. G., Paul, Suvash Chandra, Tan, Ming Jen
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2016
• Subjects: Concrete; Deformability
• Online Access: https://hdl.handle.net/10356/84556; http://hdl.handle.net/10220/41820
• Institution: Nanyang Technological University

Different manufacturing processes demand appropriate materials processing adjustments. This holds true for concrete materials that have versatility in processing, including normal mixing and casting in the construction industry; spraying or so-called shotcrete application in soil stabilization for mining or construction excavations, extrusion in pre-casting factories for structural elements intended for the construction industry; and spinning manufacturing processes for concrete pipes. Recent innovation in 3D printing for construction demands yet another adaption of the mix design and manufacturing process. This paper presents an overview of required adaptions in terms of mix ingredients and mixing process and equipment to produce the appropriate rheology in the fresh state, rate of viscosity change for dimensional stability, sufficient adhesion/cohesion for interlayer bond, and appropriate, specified hardened and fresh rheology. Attention is given to fresh rheology and the chemical additives to prevent ingredient segregation during mixing and processing, despite a range in fluidity required by the various processes from highly workable for pumping, to dough-like consistency for extrusion and 3D printing.