Study of Nozzle Design and Development of Reinforcing Mesh Approach for 3D Construction Printing

As 3D construction printing (3DCP) gains wider acceptance, there is a growing imperative to effectively optimise nozzles and control quality. However, nozzle-related effects have not been well established due to the complexity of extrusion-based processes and the anisotropy of mechanical properties. This thesis aims to develop a deep understanding of the nozzle-related effects by survey research and experimental analysis and then to develop a nozzle to achieve better-reinforcing performance of 3DCP. Firstly, an initial exploratory study of the nozzle-related parameters and their contribution and barrier in 3DCP was conducted through a questionnaire survey of 109 relevant stakeholders from 3DCP firms. The results show that the optimisation of nozzle-related parameters has made important contributions to printed accuracy, interlayer bonding, and deformation resistance. Also, the key barriers faced in optimising nozzle-related parameters could be categorised into four aspects, namely: (i) technology, (ii) market, (iii) economic management, and (iv) social environment. Further, nine nozzles with distinct geometric outlets were designed and fabricated elaborately to probe the effects of nozzles with different outlet shapes on the properties of printable mortar and clay. The results indicate that specimens printed with the rectangular nozzle exhibited higher deformation resistance and stronger interlayer bonding compared with those printed with the circular nozzle. For the vertical deformation in clay printing, the rectangular nozzle also shows a greater dimensional stability. In addition, the adoption of rectangular nozzles in mortar printing introduces relatively stronger compressive strength, and the larger aspect ratios result in better surface roughness. Additionally, an innovative split nozzle was designed to achieve continuous mesh reinforcement in horizontal and vertical directions. Printed components with reinforced mesh were compared with non-reinforced components via compressive tests and flexural tests to validate the effectiveness and feasibility of the proposed reinforced method. The evaluated nozzle outlet shapes and proposed nozzle design provide a scientific paradigm reference for the selection and development of nozzles in 3DCP.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2026

Author dc:creator

• Yang, Liming

• 3D construction printing
• nozzle
• 3D-printed clay
• reinforcement
• quality control
• anzsrc-for: 330201 Automation and technology in building and construction

Statement dc:rights

• open access
• CC BY 4.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by/4.0/

Language dc:language

en

Identifier

https://doi.org/10.26190/unsworks/32301

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/107818