Buildability analysis on squared profile structure in 3D concrete printing (3DCP)

Abstract

Numerical modelling and simulation approaches can be used to optimize material combinations, structural design, and process parameters to achieve the desired structural performance of 3D-printed structures. In this study, a novel construction and demolition waste-based mortar mixture was prepared for the 3D concrete printing (3DCP) process. A square cross-sectional structure was designed and 3D-printed using a lab-scale gantry-type 3D printer for buildability analysis. The geopolymer material was also characterized to obtain time-dependent properties for use in a numerical model capable of predicting the buildability (final height) of structures. In the numerical modelling and simulation phase, predictive simulations were performed for experimentally 3D-printed structures to validate the predictability of the numerical model. The numerical model revealed a sound approximation of buildability with an error of 6.3% only. Furthermore, using numerical simulations, sensitivity analyses were performed to evaluate the impact of designed height and 3DCP process parameters (i.e., printing speed and layer width) on the buildability of structures. The numerical modelling and simulation results revealed a strong impact of both process parameters (i.e., printing speed and layer width) on the buildability of 3D-printed structures. A maximum buildability of 410.6 mm was achieved for structure 3D-printed at a printing speed of 20 mm/s and layer width of 45 mm. Overall, an improved buildability was observed for lower printing speeds and higher layer widths; however, the buildability performance was more sensitive to the layer width.

Keywords:

• Geopolymer
• concrete 3D printing
• numerical modelling
• simulations
• buildability

Acknowledgments

Open Access funding is provided by the College of Science and Engineering, Hamad Bin Khalifa University, Qatar. The authors gratefully acknowledge the financial assistance of the Qatar National Research Fund (QNRF; AICC02-0429-190014) and the Scientific and Technical Research Council of Turkey (TÜBITAK) provided under the TÜBITAK–QNRF Joint Funding Program (Project #119N030). The authors also gratefully acknowledge the financial assistance of TÜBITAK provided under Project #122M556. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of TÜBITAK or QNRF.

Disclosure statement

The authors declare no conflict of interest.