Story by Ed Crowell

Military troops learn to live and sleep in unusual spots — from inside a desert foxhole to wedged between a rock and a hard place.

Now, some Texas soldiers will have an opportunity to rest, comfortably, in a revolutionary new barracks in Bastrop County.

At Camp Swift — the National Guard’s main training facility in Texas — some troops will sleep in the largest structure in North America built by a giant robotic 3D printer.

The computer-guided printer produced long, narrow and thin layers of a specialized concrete mixture to form walls for the 3,800-square-foot structure.

The 72 personnel who will use the barracks will be the first troops in the world housed in a 3D-printed building, according to military representatives and ICON, an Austin company that develops advanced construction technologies. The company built the Camp Swift barracks in partnership with the Texas Military Department.

The massive printer, which looks somewhat like a bridge, spanned the width of the building’s already completed concrete slab foundation. It moved on rollers along the foundation’s length, as programmed, while monitored through the computers of on-site operators for ICON.

The printer weighs 9,500 pounds and is 15½ feet tall by 46½ feet wide. It can print a wall up to 10½ feet high.

As the printer rolled along the edges of the barracks’ foundation, the walls were formed with a proprietary concrete mixture called Lavacrete made by ICON. A nozzle on the printer that resembles a jumbo pastry piping bag pumped out 2- to 3-inch-wide layers of the wet concrete mixture until 105 layers were in place.

The new white-walled barracks, which has two large rooms separated by a breezeway, stands in contrast to the collection of concrete block and corrugated metal quarters of varying ages at Camp Swift, which was originally built during World War II.

The military facility is between Bastrop and Elgin off Texas 95. U.S. Army and Texas National Guard troops train there, using a variety of gunnery ranges and vehicles to stay prepared for emergency deployments.

“Texas has become a technological center of gravity within the nation,” said Maj. Gen. Tracy Norris, Adjutant General of Texas. “The Texas Military Department is proud to be a conduit for introducing these innovative solutions into the military community.”

The long-range plan at Camp Swift is to build seven more barracks to replace older ones, perhaps using 3D printing for the new ones.

It took the 3D printer only 120 hours to build the barracks walls, said Army Col. Zebadiah Miller, director of facilities for the Texas Military Department headquartered at Camp Mabry in Austin. That was a fraction of the year it took to build the floor slab, roof, windows, bathrooms, wiring, air conditioning and the outdoor walkway ramps.

The barracks are double-walled, with the second same-sized wall printed 6 inches away from the first. Metal tie-rods and insulating foam fill the gap between the two walls.

Military officials said the concrete mixture’s strength was rated at 6,000 psi (pounds per square inch), making it waterproof and double the usual psi rating for residential walls.

The walls curve instead of having traditional corners. Printing in 3D often includes curving or circular designs because corner joints are unnecessary. The curves in dwellings made with 3D printers have been described by some as making a resident feel embraced, like getting a “house hug.”

For the barracks, long windows were set atop the one-story walls. A metal roof supported by metal beams topped off the building. The large rooms have bunk beds, bathrooms and plentiful electric outlets so troops can plug in their computers and phone chargers.

It all brings a smile to Miller, who said the project began after he returned from Afghanistan in late May of 2020. “It happened very fast, even with delays during the winter (2021) freeze and protocols for Covid,” he said.

A micro-grid generator was installed near the new barracks with the assistance of Bluebonnet Electric Cooperative. The natural gas-powered generator could supply electricity to the barracks and other Camp Swift facilities for two weeks without refueling if power were interrupted, military officials said.

“The printed barracks will not only provide our soldiers a safe and comfortable place to stay while they train, but because they are printed in concrete, we anticipate them to last for decades,” Miller said. The barracks, when occupied, are expected to be more energy efficient than the old quarters nearby. Although no prices were made available, the cost of the 3D printed barracks could be significantly less expensive than a traditional barracks.

ICON is a fast-growing, four-year-old company that started by making small 3D-printed houses in Mexico. Before contracting with the company, Miller and other officials with the Texas Military Department visited ICON’s development laboratory and several previously built structures.

The first Central Texas project for ICON was at the 51-acre Community First! Village in Northeast Austin for people who were living without homes. Housing and support services have been provided there since 2015. A welcome center and six tiny houses, both made by 3D printing, were added to the development.

More recently, ICON built four larger, stylish new homes for sale on East 17th Street in Austin. The two-story houses (only the first floors were 3D printed) sold quickly for prices ranging from $450,000 to $800,000.

The Camp Swift barracks and the 17th Street houses were designed by Logan Architecture of Austin.

Funding for the Camp Swift project came from the federal Small Business Innovation Research Strategic Fund, the Texas Military Department and the U.S. Air Force’s in-house innovation incubator known as AFWERX.

The 3D-printing process is under evaluation by the military for suitability in troop deployment locations, potentially reducing construction time, costs and risks.

ICON isn’t just looking at Earth-bound projects. The company is working with NASA to develop prototypes for dwellings on the moon and, eventually, on Mars.

“Building humanity’s first home on another world will be the most ambitious construction project in human history and will push science, engineering, technology and architecture to literal new heights, said Jason Ballard, co-founder and CEO of ICON. “NASA’s investment in space-age technologies like this can not only help to advance humanity’s future in space, but also to solve very real, vexing problems we face on Earth.”

Printed-home community planned 

Another major 3D building project by ICON is to build 100 houses in the Austin area in partnership with Lennar, one of the largest homebuilders in Texas.

There are 18 Lennar subdivisions in Central Texas, and one is Sun Chase in Del Valle, which is served by Bluebonnet Electric Cooperative.

The builder and the 3D printing company have not revealed the project's location, but have stated that it will be the largest community of concrete-printed homes in the world. The companies partnered with the Bjarke Ingels Group, based in New York and Copenhagen, to design the houses.

Concept drawings show one-story houses with metallic photovoltaic roofs on every house to capture solar energy.

Lennar says the cost of these 3D-printed homes will be similar to other Lennar homes in the area, according to a quote in the Wall Street Journal from Eric Feder, president of LENX, Lennar’s investing arm.

The median home sale price in the Austin metro area in October was $455,000, according to the Austin Board of Realtors.

Jason Ballard, ICON’s co-founder and CEO, noted the existing housing supply deficit of 5 million new homes in the United States. “There is a profound need to swiftly increase supply without compromising quality, beauty or sustainability, and that is exactly the strength of our technology,” he said.

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