Innovative approach to 3D concrete printing
Australian scientists have developed an innovative approach to the 3D printing of concrete using cement and geopolymer binding. The technology has the potential to change the way we build with concrete, saving costs in formworks and allowing freeform construction.
“We have successfully made the first in-roads into this area by separately using Portland cement and geopolymers as binders in 3D printing machines,” Professor Sanjayan, Director of the Centre and Professor of Concrete Structures at Swinburne University, says.
Combination of digital and materials technologies
Unlike the conventional approach of casting concrete into a mould, 3D concrete printing combines digital and materials technologies to allow free-form construction without the use of formwork. In 3D printing the construction is through layer-by-layer addition of material, offering the ability to build components that are otherwise impossible or too expensive to build.
Independent of the shape
“Engineering and architectural designers are currently constrained to rectilinear designs due to the requirements of formwork systems,” Sanjayan says. “3D printing will provide the freedom to produce a structural component independent of the shape. It has the potential to make a major shift in quality control in construction automation, since machines are better at performing repetitive tasks with high accuracy.”
Overcoming technical hurdles
The researchers adapted an existing 3D printing machine to use cement materials combined with fine aggregates to build 3D structures. This prompted the machine makers to invest in making machines for construction applications. “By choosing the correct particle size distributions and binder deposition methods we have demonstrated how the various technical hurdles can be overcome,” Sanjayan says.
Sustainable alternative to Portland cement
“We have also shown that geopolymers produced from industrial by-products are a sustainable alternative to the Portland cement system and are more suitable for the 3D printing process as well as how post-processing methods can increase the strengths”, Sanjayan adds. Swinburne’s innovative approach to 3D concrete printing has been recognised at the annual Concrete Institute of Australia (CIA) awards. The Centre for Sustainable Infrastructure has won the CIA’s Victorian award for Excellence in Technology and Innovation.
