Quantifying water-driven geometric uncertainties in powder bed concrete printing using high-resolution 3D modeling
For researchers and practitioners in additive manufacturing of concrete, this work quantifies water-driven geometric uncertainties and offers a compensation strategy, though the findings are incremental and domain-specific.
This study quantifies how small changes in water content in powder bed concrete 3D printing cause large, systematic geometric deviations such as edge rounding and swelling, and demonstrates a design-compensation method that pre-adjusts digital geometry to improve accuracy without post-processing.
Dimensional accuracy in powder bed 3D printing of concrete is strongly influenced by binder distribution, and the resulting geometric deviations can be direction-dependent. This study examines how voxel-wise water dosage influences geometric fidelity and deviation anisotropy. Experiments show that small changes in water content can cause large, systematic deviations, including edge rounding and swelling. We quantify these effects using high-resolution stereophotogrammetry, aligning as-built scans with CAD models. We then compute deviation metrics such as point-wise distance errors and volumetric differences across multiple water-dosage settings, revealing repeatable, directionally biased deformation patterns that intensify with higher water content. Mechanical testing indicates that stiffness and strength change only marginally, with no clear trend in the tested range. This is explained by excess voxel water diffusing into surrounding powder, leaving the effective water-cement ratio largely unchanged. Finally, we demonstrate a design-compensation concept that pre-adjusts digital geometry to counter predictable deviations, improving accuracy without post-processing.