Buildability Analysis on Squared Profile Structure in 3D Concrete Printing (3DCP)

Abstract

Numerical modeling 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 CDW-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 of concrete structures. In the numerical modeling 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 modeling 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 410.6mm was achieved for structure 3D-printed at a printing speed of 20mm/s and layer width of 45mm. 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 modeling
• simulations
• buildability