New research involving lobsters could potentially improve 3D printed concrete, allowing for more complex and creative architectural structures.
In an experimental study, RMIT researchers looked at the natural strength of lobster shells to design special 3D printing patterns.
The bio-mimicking spiral patterns improved the overall durability of the 3D printed concrete, as well as enabling the strength to be precisely directed for structural support where needed.
When the twisting patterns were combined with a specialised concrete mix enhanced with steel fibres, the resulting material was stronger than traditionally-made concrete.
Lead researcher Jonathan Tran said 3D printing and additive manufacturing opened up opportunities in construction for boosting both efficiency and creativity.
“3D concrete printing technology has real potential to revolutionise the construction industry, and our aim is to bring that transformation closer,” Tran said.
“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.
“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.”
One of the most conventional patterns used in 3D printing is unidirectional, where layers are laid down on top of each other in parallel lines.
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The new study published in a special issue of 3D Printing and Additive Manufacturing investigated the effect of different printing patterns on the strength of steel fibre-enhanced concrete.
Previous research from the RMIT team found that including one to two per cent steel fibres in the concrete mix reduces defects and porosity, increasing strength. The fibres also help the concrete harden early without deformation, enabling higher structures to be built.
The team tested the impact of printing the concrete in helicoidal patterns (inspired by the internal structure of lobster shells), cross-ply and quasi-isotropic patterns (similar to those used for laminated composite structures and layer-by-layer deposited composites) and standard unidirectional patterns.
Tran said the spiral patterns hold the most promise for supporting complex 3D printed concrete structures.
“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,” he said.
“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.”