In-situ 3D Concrete Printing of a Vaulted Ceiling Using a Mobile Robot

The geometric efficiency of vaulted ceilings makes them relevant to material-conscious construction, yet their automated in-situ fabrication remains challenging. This paper asks whether a mobile robot equipped for extrusion-based 3D concrete printing can accurately fabricate self-supporting vaults from below in spatially constrained environments through collision-free motions. The method combines layer-wise form-finding, onboard material supply, lightweight near-nozzle activation, redundancy-aware motion planning, and a print–drive–print workflow implemented with a mobile manipulator. Experiments establish feasibility: 14 full-scale vault segments up to 960 mm long were fabricated in approximately 15 min each, with laser scanning revealing standard layer-height deviations of around 0.5 mm. These findings provide architects, fabricators, and construction-robotics researchers with a basis for material-efficient ceiling fabrication in constrained construction and renovation contexts. They motivate research into continuous print-while-driving control, automated localization, cold-joint performance, structural testing, process robustness, and life-cycle impacts toward scalable in-situ construction under realistic site conditions.