New CFD Model Improves Geometric Precision in 3D Concrete Printing

An international research team has developed a numerical model that can more accurately evaluate and predict the geometric quality of 3D-printed concrete structures. The aim of the study was to investigate the influence of process parameters and material properties on the dimensional accuracy of additively manufactured components. The work was carried out in collaboration between Qingdao University of Technology, ETH Zurich, Ghent University, and several Chinese industry partners.

3D concrete printing is considered a promising construction method, as it enables the creation of complex structures without formwork, while reducing material use and labor effort. At the same time, ensuring geometric quality remains a major challenge. Variations in printing speed, nozzle height, or material rheology can lead to uneven layer thicknesses and deformations that compromise structural stability. Previous approaches have often relied on experimental procedures that are time-consuming and material-intensive.

The newly presented model is based on Computational Fluid Dynamics (CFD) simulations and describes the flow and solidification behavior of concrete during the printing process. To validate the model, the researchers compared the simulation results with physical cross-sections that were analyzed using image processing techniques. The findings showed that the model reproduces the actual geometry with high accuracy. At a nozzle height of 15 millimeters, the error in the cross-sectional area was only four percent, while deviations in height and width remained below one percent.

The study also revealed that higher printing speeds result in narrower layers, while larger nozzle diameters with adjusted material flow lead to more uniform layer shapes. In particular, the yield stress of the material significantly affects the shear behavior during extrusion. According to the researchers, the developed model provides a reliable foundation for systematically optimizing printing parameters to improve both the geometric precision and structural integrity of 3D-printed concrete.