The US Marine Corps developed a technology to construct a concrete building with a 3D printer in 24 hours

Techniques have been developed that make barracks (barracks) that allow a number of soldiers to stay in bed by stacking thin layers of ready-mixed concrete using 3D printers. With this device, it is possible to create barracks that had been constructed by 10 soldiers over the past five days in a minimum of 24 hours.

Marines 3D-print concrete barracks in just 40 hours | Fox News
http://www.foxnews.com/tech/2018/08/29/marines-3d-print-concrete-barracks-in-just-40-hours.html

You can see that the barracks built with 3D printers are made from stacked layers of thin concrete. For test cases or roofs not attached, you can see features different from ordinary construction around wavy shaped walls.

In this technology, the US Marine Corps' Additive Manufacturing Team collaborated with the 1st Marine Expeditionary Force and used the world's largest concrete 3D printer developed by US Army Engineer Research and Development Center What you realized. In the experiment, it seems that we succeeded in completing a barracks area of ​​500 square feet (about 14 tsubo) in about 40 hours.

In the experiment of this time, we succeeded in constructing a 3D printer controlled by a PC 10 years ago. It took about 40 hours because it was construction while checking engineers and refilling concrete, but with the automatic concrete replenisher, the speed enough to finish construction within 24 hours using the automatic concrete replenisher It seems there is.

This shape is unique to 3D printers. While stacking round layers of rod-shaped concrete with menium and injecting layers, you can see that there is a gap between the wall and the wall if you look closely. By doing this you can realize reduction of concrete fee, so it is possible to construct barracks efficiently even on the battlefield where goods are limited. In addition, since concrete produces a lot of carbon dioxide at the time of raw material production, it reduces carbon dioxide emissions by reducing usage.

Also, the biggest merit is that it reduces the number of personnel involved in construction and can improve safety. By delegating the barracks that 10 soldiers had built over the past five days to nearly automatic machines it is no longer necessary to take risks near the front lines because troops are kept to a minimum It can be said that it coincides with the theory that keeps power to the maximum.