Formwork-Optimization for Complex 3D Concrete Printing (2024-09)¶

3D Concrete Printing (3DCP) revolutionizes architecture with speed and sustainability. Yet, current methods mainly use extrusion in 2.5 dimensions, limiting complex shapes. Challenges remain in achieving intricate morphologies, such as non-conventional cavity walls, as well as overcoming limitations posed by overhanging structures, and inclined surfaces with protrusions, leading to exploration of additives like chemical accelerators. However, uncertainties in effectiveness persist, posing challenges in strength and handling. Overcoming these limitations is vital for unlocking 3DCP's full potential in construction. This study delves into the underdeveloped digital formalization and prevention of failure modes in 3DCP for intricate 3D morphologies, particularly focusing on the challenges encountered in the construction of overhangs and subsequently cavity wall construction, using aggregate support materials as formwork. It introduces a structured selection process, leveraging Finite Element Analysis (FEA), to understand the crucial role of lateral pressure in supporting these complex structures. Theoretical analysis, rooted in earth pressure analysis theory, informs the selection of appropriate aggregate materials, which are then validated through experimental testing. This comprehensive approach uncovers essential attributes for support materials, enabling alignment with various formwork families based on specific requirements like insulation or reusability. Through a series of physical prototyping, including cylinder samples produced via robotic 3DCP, the practical applicability of these findings is solidified. Ultimately, this study contributes significant insights into optimizing 3DCP methodologies for complex geometries, bridging a critical gap in formalization and advancing the field of 3DCP.