A research team within the U.S. Army Corps of Engineers recently 3-D printed full-scale concrete walls in an effort to create quick-to-assemble barracks for field housing, according to Engineering News Record. The project, named Automated Construction of Expeditionary Structures (ACES), aims to engineer structurally efficient and safe concrete barracks with precast roofs and 3-D-printed walls. In their latest tests, they were able to produce 9.5-foot-tall reinforced concrete walls for 32-foot by 16-foot barracks, made from about 25 cubic yards of concrete. The next phase of the testing will tackle printing concrete roof beams. Backed by the U.S. Marine Corps, Caterpillar Inc., NASA’s Marshall Space Flight Center, and the Kennedy Space Center, ACES is pushing the boundaries of military on-site construction using as little money and manpower as possible. The project has undergone two years of testing with structural engineering experts from the Chicago office of Skidmore, Owings & Merrill, who had previous experience working in 3-D printing through a project with the U.S. Department of Energy. After several iterations, the group concluded that construction time on such structures could shrink to a single day as opposed to five days, the average amount of time it takes to build wood-framed barracks. Printing concrete barracks would also eliminate the need to ship construction materials for conventional barracks by instead using local concrete from wherever the build-out would occur. For this prototype, ACES spent $6,000 and in addition, found out that it would take just three trained crew members per shift for three continuous printing sessions to build the barracks. Though exhausting, the process is even less labor intensive than basic barrack construction. While 3-D-printed building technology is looking more viable every day, it's not perfect yet. According to ENR, SOM said that pre-testing the performance of the concrete is imperative and that the printing process must not be interrupted to ensure overall structural efficiency. Cracks from shrinkage can occur on long, straight walls as well, so ACES employed a chevron design that undulates, changing direction every two feet. ACES will do further testing over the next month to refine the technology and the construction process. They expect to be done with the project's precast concrete roof in September and will then issue a report with design guidelines. During 2019, the group hopes to build four or five pilot machines for Marine Corps units to use in the field for additional evaluation.
Posts tagged with "military":
Dubbed Megacities: Urban Future, the Emerging Complexity, this video (obtained by The Intercept) foresees a dark urban future that will challenge the U.S. military's ability to target adversaries. The video also makes clear that these urban environments will be the new battlegrounds for global stability and security. According to The Intercept, the video was created by the U.S. Army for military audiences. While it's common knowledge the world is urbanizing, Megacities explores the tactical and strategic implications of enormous metropolises. Predicting that "living habitats will extend from the high rise to the ground-level cottage to subterranean labyrinths each defined by its own social code and rule of law," the video's vision for the future seems inspired by Judge Dredd (or insert your dystopic urban fiction here). "The urban environment will be the locus where the drivers of instability will converge," the narrator intones. The Pentagon also implies that the shared expertise, or at least interlinked understanding, that urban and military planners share won't apply to these environments: "Megacities are complex systems where people and structures are compressed together in ways that defy both our understanding of city planning and urban doctrine." The Pentagon's conception for the megacity relies on a few assumptions: These are ethnically and religiously heterogeneous places, where rapid urbanization and modernization causes a cultural shock and poverty and poor infrastructure runs rampant. Also rocked by climate change, these megacities have failed by most quantifiable measures. "The cities that grow the fastest will be the most challenged as resources become constrained and illicit networks fill the gaps left by overextended undercapitalized governments," says the narrator. These failed cities harbor and nurture "non-national state, unaligned individuals and organizations," a shadowy and vague opponent. The Pentagon foresees these cities as global threats, with these non-state actors profiting from international cybercrime while benefiting from plenty of places to hide or evade pursuit. Unable to avoid urban combat or evacuate massive civilian population before attacking, the military can't resort to the conventional approaches used from World War II to Iraq and Afghanistan. New tactics must allow the military to "rapidly return the city to the people" but also "operate within these ecosystems with minimal disruption in flow." What exactly this means isn't clear, though the video clearly states that in the future "urban operations become the core requirement for the future land force."
After four years in the making, St. Paul, Minnesota earlier this year opened a new tribute to the military families—the first monument aimed directly at the family members of those in the armed forces, as opposed to the service men and women themselves. The Minnesota Military Family Tribute was conceived and bankrolled by the nonprofit Minnesota Military Family Foundation, founded in 2004 by entrepreneur and Minnesota Timberwolves co-owner Bill Popp. Popp hired HGA to realize the project, after a jury working with the Capitol Area Architectural Planning Board selected the Minneapolis-based designers as the winners of a public competition. “The Military Family Tribute will forever stand as a personal thank you to each spouse, significant other, child, parent, grandparent, sibling and any other person a soldier defines as family who provides the true foundation of support to our military personnel,” Popp's organization, the Minnesota Military Family Foundation, said in a statement when the designs were unveiled in 2011. Major design elements include a sweeping walkway with seasonal landscape designs, 87 story stones representing all of the state's counties, and a Gold Star table where “All are welcome to the table to share gratitude and to remember fallen service members and Gold Star Families,” according to the project description. Via the architects, here's a gallery of images by photographer George Heinrich showing the completed project: