As we’ve seen through recently constructed office buildings in Dubai, bridges in the Netherlands and low-cost housing in Latin America, 3D printing is beginning to shape the way modern structures are formed, and new research could further widen the potential of this technology. Scientists at Australia’s RMIT University have come up with 3D printing technique for concrete that affords it greater strength, by mimicking the curvy patterns found on lobster shells.
The RMIT University researchers were experimenting with different approaches to 3D-printed concrete, hoping to land on one that could open up new possibilities in this emerging form of architecture. Where concrete structures are generally formed by casting the material in a mold, those created using 3D concrete printing (3DCP) are gradually formed by printing one layer on top of another in parallel lines.
As part of their research, the scientists included 1 to 2 percent steel fibers in their concrete mix and investigated a variety of alternatives to the unidirectional patterns typically used in 3D printing, but found particular success in what’s known as helicoidal patterns. These were inspired by the internal structure of lobster shells, which through evolution have come to offer the crustaceans a hardy protective shield.
“Our study explores how different printing patterns affect the structural integrity of 3D-printed concrete, and for the first time reveals the benefits of a bio-inspired approach in 3DCP,” says lead researcher Dr Jonathan Tran. “We know that natural materials like lobster exoskeletons have evolved into high-performance structures over millions of years, so by mimicking their key advantages we can follow where nature has already innovated.”
According to the researchers, the enhanced strength brought about by these helicoidal patterns could allow for taller and more complex concrete structures to be 3D printed. They will explore these possibilities with the help of a new 5 x 5-m (16 x 16-ft) mobile robotic printer, along with examining how these types of 3D-printed concrete structures might be made with the help of recycled waste materials.
“As lobster shells are naturally strong and naturally curved, we know this could help us deliver stronger concrete shapes like arches and flowing or twisted structures,” Tran says. “This work is in early stages so we need further research to test how the concrete performs on a wider range of parameters, but our initial experimental results show we are on the right track.”
The study was published in the journal 3D Printing and Additive Manufacturing, and the video below provides an overview of the research.
Source: RMIT University
