Design, Fabrication, and Verification of LABLAB 2.0: A Large-Scale Multi-Part 3D Concrete Printed Sculpture
This paper details the end-to-end workflow for designing, fabricating, and verifying LABLAB 2.0, a large-scale multi-part 3D concrete sculpture, demonstrating that successful implementation relies not only on material and printing performance but also on critical factors such as segmentation logic, handling strategies, tolerance management, and workflow organization.
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Imagine a construction site where the usual heavy machinery and piles of bricks are replaced by a single, giant robotic arm. Instead of laying one brick at a time, this machine squeezes out a thick, wet paste of cement, building a structure layer by layer, much like a giant 3D printer creates a plastic toy. This technology, known as 3D concrete printing, has moved from laboratory experiments to real buildings, offering a way to create shapes that would be too difficult or expensive to make with traditional molds. However, a major hurdle remains: how do you print something huge, like a statue or a bridge, when the machine itself is too small to reach every corner? The answer lies in breaking the object into smaller, manageable pieces that can be printed separately, moved into place, and snapped together like a complex puzzle.
This is the challenge that a team of researchers, architects, and students at Riga Technical University tackled with a project called LABLAB 2.0. They set out to design, build, and verify a large-scale sculpture made entirely of 3D printed concrete, installed on their university campus. The goal was not just to create art, but to test the entire process of turning a complex digital idea into a physical, multi-part object that could withstand the elements. The result was a towering figure standing 2.58 meters tall, composed of thirteen separate concrete sections, assembled with steel rods and chemical anchors. The project revealed that while the printing technology works, the real difficulty lies in the invisible work of planning, the logistics of moving heavy wet concrete, and the precise adjustments needed to make the pieces fit together perfectly.
The journey began with a design competition where students proposed ideas for the sculpture. The winning concept was a complex, curved form that resembled a stylized human figure, but its shape was too large to fit inside the printing machine, which had a maximum workspace of about one meter by one meter. To solve this, the team had to digitally slice the sculpture into smaller segments. This was not a simple cut; every piece had to be small enough to print without collapsing, light enough to lift with a crane, and shaped so it would connect securely to its neighbors. The team spent months refining these digital models, constantly checking if the shapes could actually be printed and how they would be handled later. This phase of digital preparation turned out to be the most labor-intensive part of the entire project, requiring more human effort than the actual printing or assembly combined.
Once the digital plan was locked in, the team moved to the factory floor to print the parts. They used a special dry mix of concrete that contained oil shale ash and metakaolin, materials chosen to reduce the amount of cement needed and improve the mixture's ability to hold its shape as it was extruded. The machine, a large gantry system with a nozzle about the width of a finger, squeezed out the material in continuous lines. Over the course of a month in July 2025, the team printed all thirteen components. The process took about twenty-six hours of actual machine time, but the total effort, including mixing the concrete, cleaning the equipment, and moving the heavy parts to storage, stretched to nearly sixty hours. The team printed 3.7 tons of dry mix material, creating parts that ranged from the base of the feet to the top of the helmet.
The printing itself was mostly successful, but it was not without hiccups. One of the belly sections crumbled during handling and had to be printed again. Other parts showed minor issues like rhythmic pulsing in the material flow or slight twitching of the nozzle, which created small irregularities on the surface. These events highlighted that the speed of the machine was not the only factor in success; the organization of the entire workflow, from mixing the batch to moving the finished piece, was just as critical. The team found that the time spent preparing materials and cleaning the machine was a major part of the total production time, suggesting that future improvements should focus on logistics rather than just printing faster.
The final and perhaps most demanding phase was assembly. The thirteen printed pieces were transported to the campus and lifted into place using a crane and a boom lift. The team had to align the heavy concrete blocks, drill holes, and insert steel rods to hold the structure together. This process required about 130 hours of manual labor. Because the printed parts were not perfectly identical to the digital models, the workers had to spend significant time sanding down rough edges and drilling new holes to make the pieces fit. The surface of the concrete, created by layers of extruded material, was fragile at the edges, and the weight of the lifting straps caused some chipping and damage. This experience showed that for multi-part 3D printed structures, the design must account for how the pieces will be lifted and joined, not just how they look on a computer screen.
To verify the accuracy of their work, the team scanned the finished sculpture with a high-resolution 3D scanner and compared the digital map of the real object to their original design. The scan revealed that the final sculpture was slightly larger than planned, with a volume about 5% greater than the digital model. The height and width were also slightly off, with deviations of up to 5% in some directions. These differences were caused by the concrete spreading slightly as it was printed and by the way the layers settled. While these errors might seem small, they were significant enough to require extra work during assembly to ensure the pieces connected properly. The study confirmed that 3D concrete printing is a viable method for creating complex art and structures, but it also proved that the technology is not yet a "set and forget" process. It requires a deep integration of design, material science, and construction logistics, where every decision about how a piece is cut, printed, and lifted must be made long before the first layer of concrete is laid. The LABLAB 2.0 sculpture now stands on the university campus as a permanent test case, waiting to be observed over time to see how it holds up against the weather and the test of time.
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