The can now print concrete barracks, bunkers and other structures in challenging environments. Its Automated Construction of Expeditionary Structures (ACES) programme has also drawn up plans to create the world’s first 3D-printed vehicle bridge, and prototype printers should be in the field next year.
“Our priority was to develop a capability utilising 3D printing technology for use in an expeditionary environment, specifically suited for military purposes,” says Megan Kreiger, programme manager for additive construction at the US Army’s Engineer Research and Development Center in Vicksburg, Mississippi. “That means it has to ship in a container, it has to use local materials, it has to work in a dirty environment and it needs to be able to take a beating while still remaining reliable.”
Commercial printers for concrete-like materials lack this robustness, says Kreiger. For instance, they typically require special mortar. The ACES technology can 3D print concrete made with locally sourced aggregate.
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Several printers have already been developed as part of the ACES programme, including one called ACES Lite made in partnership with construction equipment company . It resembles a gantry crane, with a hose from a concrete pump and ending in a nozzle that positions the flow of concrete to build the structure layer by layer.
According to the , some ACES technology can build a sample structure in one day rather than five, with a crew of three rather than eight. Kreiger says it also gives greater freedom of design. For example, a demonstration 3D barracks building has walls that are curved at the base for strength and flat higher up. Insulation, protection or other features can be built in as needed.
“You can create complex shapes very easily at little to no added cost,” says Kreiger.
She notes that 3D-printed buildings still require roofs and other finishing touches like any other construction work. In areas where equipment, labour and materials are plentiful, the benefits of using the ACES technology may be relatively modest, but the hardware will be extremely helpful in remote areas. This includes disaster relief situations where housing, bridges and other structures are needed fast.
Kreiger’s team now plans further demonstrations, including the first ever 3D-printed vehicle bridge. Budget documents indicate that ACES prototype printers will be in the field next year.
Article amended on 27 September 2021
We clarified what was in the budget documents
