Robotic 3D Printing on Inclined Surfaces Using Adaptive Formwork Principles for Prefabricated Curve-Like Structures (2024-08)¶

3D Printing is revolutionizing the production of prefabricated modular structures in real scale. In the case of curve-like structures, the process mainly focuses on planar 2.5D Printing of modules due to geometrical and overhanging constraints. To overcome these limitations, the current work refers to the application of a robotic 3D Printing approach on inclined surfaces using cement-based material mixtures to produce prefabricated segments based on adaptive formwork principles. The approach aims to examine the effectiveness of the adaptive formworks to be applied in 3D Printing of inclined prefabricated modules, and in parallel to analyze results regarding their limitations and advantages occurred during 3D Printing in different size of curved segments, inclinations, and nozzle orientations. Initially, the study introduces three different surface types derived from a proposed adaptive pin-bed formwork, that are physically printed using respective disposal formworks. These initial experimentation aims to analyze 3D printed results in relation to the optimal number of layers of filament that can be printed, the width and height of printing filaments in each layer, the angle of printed material deposition before its potential instability (start falls) and, finally the appropriate composition of material mixtures and their ratio density (cement, sand, water, and superplasticizer). Then, the work introduces a shell structure, aiming to examine the joints of prefabricated parts through 3D Printing, and to provide the framework for the effective buildability of prefabricated curve-like segments on inclined surfaces towards their construction automation.