Hexastone
Revolutionising Construction: 3D Concrete Printing as a revival for Structural Efficiency
Germany / The Netherlands – In a collaboration aimed to fuse cutting-edge technology with traditional architectural principles, Prof. Herrmann and Prof. Spaeth (Technische Hochschule Lübeck) pioneers in computational modelling and digital structural design, joined forces with Vertico, a specialist in 3D concrete printing and Sika, a global leader in construction materials, to create this ground-breaking pavilion. This innovative project breathes new life into age-old structural principles by combining them with cutting-edge production technologies, rethinking the way we currently build with materials.
RIGHT: 3D concrete printing extruder, Source: Vertico
3D printing: Digital design to manufacturing
The pavilion demonstrates the power of 3D concrete printing, overcoming traditional manufacturing constraints. It was revealed at the Nordbau 2023, Northern Europe's largest compact trade fair for construction at Neumünster, Schleswig Holstein.
The overall shape of the structure emerged from a computational form-finding process based on structural simulations generating a compression-only shell structure. The shell geometry is tessellated into planar hexagonal tiles to allow for efficient printing on a planar printing bed. The tessellation approach also simplifies the connecting seams between individual stones. While traditional brickwork generates curvature by tapered mortar joints between uniform bricks, the curvature of the hexa-shell is generated by the individually inclined perimeter of each hexa-stone entailing the curvature of the overall shape in every stone resulting in parallel interstices between the stones.
TOP: 3D concrete printed pavilion, showing the stones. Source: Vertico
The resulting pavilion consists of a dome of 102 interlocking stones spanning about 4,5m in diameter. All 102 distinct stones of the pavilion were 3D printed by Vertico within the record time of 2 printing days. The fully digitized process, from design to production, and the flexible 3d printing enables a vast range of different geometries for the stones and subsequently for the overall shape without additional effort.
Key Highlights of the Pavilion:
Structural Efficiency: The pavilion is a testament to structural ingenuity. It embraces old architectural principles that prioritise form and function. By leveraging 3D concrete printing technology, structural efficient shapes become cost-effective. Efficient use of materials is particularly relevant as we go towards an era of potential resource scarcity, and the emissions of build structures. The pavilion aims to revive structural efficient design.
Design for Disassembly: Breaking away from the conventional "build and demolish" approach, this pavilion is engineered with the future in mind. After being showcased at the Nordbau 2023, the structure will be disassembled, and then reassembled at a location that is yet to be announced. This commitment to "Design for Disassembly" not only reduces waste but also demonstrates a sustainable approach to construction. Since the seams between the stones are only subject to compression forces the mortar is only used to compensate for tolerances. Therefore, the contact surfaces of the stones are coated with a non-adhesive agent to eliminate the potential transfer of tensile forces and to allow for easier disassembly.
TOP: Support structure of the pavilion. Source: Vertico
Optimal Material Usage: Recognizing the importance of material performance, the pavilion utilises material where it is most efficient, eliminating bending moment in its design, employing concrete for compression, and steel in tensile. This aims at a potential future where strategic material selection takes place to minimise materials used, enhancing the longevity and strength of a structure.
Education and Hands-On Experience: The construction and design of this remarkable pavilion was not only a feat of engineering but also a unique learning opportunity. As part of university classes, master students from architecture and engineering courses equally actively participated in its creation. This hands-on experience provided invaluable insights into the future of construction, fostering the growth of the next generation of architects, engineers, and builders.
The collaboration between Technische Hochschule Lübeck, Vertico, and Sika showcases how technology can potentially revive timeless architectural principles, resulting in sustainable, efficient, and aesthetically pleasing structures.
