麻豆村

When natural disaster strikes, a building鈥檚 survival often depends on how it鈥檚 built. Engineers at 麻豆村 have created a fast, highly accurate simulator for spray-based concrete 3D printing that could enable stronger, more complex and less wasteful construction by predicting how concrete behaves and solidifies, even around rebar.

Concrete 3D printing reduces both time and cost by eliminating the traditional casting molds. Yet most of today鈥檚 3D-printing concrete systems make it impossible to print around reinforcement bars (rebars) without risk of collision, limiting both design flexibility and structural integrity of builds.

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The 's and researchers in his Computational Engineering and Robotics Laboratory (CERLAB), are breaking through that limitation with a new simulation tool for 3D-printing spray-based concrete, or shotcrete.

鈥淪pray-based concrete 3D printing is a new process with complicated physical phenomena,鈥� said Shimada, a professor of聽. 鈥淚n this method, a modified shotcrete mixture is sprayed from a nozzle to build up on a surface, even around rebar.鈥�

The ability to print freely around reinforcement is especially important in places like Japan and California, where earthquakes are an imminent threat and structural strength is critical.

鈥淭o make this technology viable, we must be able to predict exactly how the concrete will spray and dry into the final shape,鈥� Shimada explained. 鈥淭hat鈥檚 why we developed a simulator for concrete spray 3D printing.鈥�

The new simulator can model the behaviors of spray concrete mixtures, including drip, spread and solidification time. This allows contractors to assess multiple printing paths and evaluate whether spray 3D printing is a feasible technique for their structure.

To assess their tool, the team traveled to Tokyo, Japan, where Shimizu Corporation already operates spray 3D-printing robots. With 90.75% accuracy, the simulator could predict the height of the sprayed concrete. The second test showed that the simulator could predict printing over rebar with 92.3% and 97.9% accuracy for width and thickness, respectively.

Future work will aim to increase accuracy by identifying environmental parameters like humidity, optimize performance, and add plastering simulation to create smoother finished products.

鈥淭here are still so many applications and technologies that we can develop with robotics,鈥� said Kyshalee Vazquez-Santiago, a co-author of the paper and a mechanical engineering Ph.D. candidate leading the Mobile Manipulators research group within CERLAB. 鈥淓ven in concrete 3D printing, we are working with an entirely new type of application and approach that has so many advantages but leaves so much room for further development.鈥�