Title:
3D Printing with Concrete: Development of a Vibrating Nozzle for Material Extrusion
Author(s):
Karthik Pattaje Sooryanarayana
Publication:
Web Session
Volume:
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
10/23/2022
Abstract:
The rheological requirements for 3D printing of concrete are two-fold. During pumping and extrusion, the concrete needs to behave like a fluid, and solid like after extrusion to resist the self-weight of the layer as well as the weight of subsequently printed layers. Vibration can be used to alter the yield stress of fresh concrete to control its fluid/solid state. Vibration causes an immediate and reversible reduction in the yield stress of granular suspensions such as concrete. A modified concrete rheometer was used for the rheological characterization of concrete mixtures during vibration. The effect of changing mixture design and vibration parameters of the rheology of concrete was studied. A prototype vibrating nozzle is being developed to understand the relation between rheology and the printing process (see attached figure). Material deposition by the vibrating nozzle can potentially lead to greater layer height and faster 3D printing. Vibration allows for the printing of cementitious mixtures with coarse aggregates and has the potential to make 3D printing of concrete more economical, durable, and sustainable. This study evaluates the implication of using vibration to deposit concrete using the vibrating nozzle prototype. Rheological limits are being established to define the printability of the concrete mixtures.