Volume - forming 3D concrete printing using a variable - diameter square nozzle

3D Concrete Printing (3DCP) process is rapidly developing worldwide, showing its ability to construct large-scale components or even a building. However, the current 3DCP process has found it hard to manufacture architectural components with detailed ornamentations and features on their surface due to the Fused Deposition Modelling (FDM) manner that generates fixed-width thick filaments. This paper introduces a novel Volume Forming 3D Concrete Printing (VF3DCP) method applying a variable-diameter square nozzle to manufacture architectural ornaments. The VF3DCP method directly fabricates a variable cross-section volume during one-time work instead of an FDM accumulation process. A VF3DCP extrusion kit prototype containing a steering module and a nozzle-varying module and a particular adaptive tool path planning algorithm are developed. Functional relationships of four key process parameters for a trial material, including nozzle diameter, nozzle moving velocity, material extrusion rate and tool path curvature radius, are fitted by process tests. Finally, a case study into a VF3DCP architectural carve pattern is conducted, which shows the potential of the proposed method in manufacturing architectural ornaments. © 2018 The Authors. Published by Diamond Congress Ltd. Peer-review under responsibility of the scientific committee of the Creative Construction Conference 2018.