The U.S. Marines recently tested a 3D printer capable of constructing entire buildings with quick-drying concrete. In just 36 hours, ICON's Vulcan 3D printer whipped up a concrete structure that can hold a HIMARS truck-mounted multiple rocket launcher system.
The result is a durable structure that can be built virtually anywhere the Marines deploy, sheltering personnel, vehicles, and supplies from the weather. See the printer in action here:
Source: Popular Mechanics.