CAP Fellow’s Experiment in Concrete Debuts at Architectural Mecca

The mood in the Department of Architecture this past summer was a buzz of excitement floating above an undercurrent of jitters.

That’s because, after months of planning and development, Design Innovation Fellow Christopher A. Battaglia had begun assembling an experimental architecture pavilion on the grounds of St. Peter’s Lutheran Church in the architectural mecca of Columbus, Indiana.

Normally, a project wouldn’t generate this much anxiety.

But Battaglia’s was part of a high-profile architectural exhibit in a city synonymous with modern design. He earned a spot in the juried exhibition because his submission was especially daring.

Battaglia called it “DE|stress.” His plans were to put together a vaulted concrete shell from 110 unique concrete panels he’d fabricated on campus using 3D printing. The design relied on the physics of pure compression. That means the inward force from the weight of the panels is the only thing holding the structure together, like an arch.

As optimistic as they were, Battaglia’s colleagues in the R. Wayne Estopinal College of Architecture and Planning didn’t know what to expect. What if a panel cracked, for example?

Some joked that they were thankful the project was on church grounds, because Battaglia was going to need prayers.

Still, they agreed that if anyone could pull it off, it was their 20-something colleague with visionary ideas.

Pushing boundaries

In a white hard hat and black T-shirt, the dark-haired Battaglia sat inside the cab of a rented telehandler with big knobby wheels and a cranelike boom.

Using a joystick, the researcher delicately maneuvered the machine’s telescoping arm down, in and out. At the arm’s end, a concrete panel dangled from a nylon strap.

Beneath all this overhead commotion, Battaglia’s structure resembled an avant-garde igloo. Perched on top, Battaglia’s building partners used their hands to guide the panel into place.

This was the scene at St. Peter’s as Battaglia prepared for Exhibit Columbus’ opening weekend in August.

His project pushed the boundaries of architecture and challenged the status quo. After all, that’s exactly what Ball State hired him to do.

Battaglia’s research interest right now is developing and improving 3D printing techniques, also called additive manufacturing, for precast concrete.

“We’ve been doing precast concrete the same way for 100 years,” he said.

By exploring 3D printing, Battaglia is applying cutting-edge automation to an old-school, rather unglamorous building material. The goal is to make precast concrete more versatile, more attractive, more sophisticated, and more efficient.

Traditionally, precast concrete products have come in basic, straightforward forms: wall panels, blocks, pillars, and girders, for example. Making complex forms was theoretically possible but practically and economically unfeasible—especially for one-off pieces—due to the amount of time, labor, and skill required.

On Battaglia’s project, however, each of the 110 concrete panels is unique. Adding further complexity, each piece curves in two directions. It all fits together like a giant three-dimensional puzzle.

“This project,” said Professor of Architecture Timothy Gray, “is an amazing use of innovative technology.”

The process

Teaming up with Battaglia’s past thesis advisor, Martin Miller from Cornell University, Battaglia began the design collaboration of “DE|stress” in 2018. He and CAP undergraduate researcher Ethan Jones began fabricating the panels in May 2019. Helping in various critical stages of the project were CAP professors Janice Shimizu, Josh Coggeshall, and James Kerestes, as well as several of the college’s undergraduate and graduate students.

Printing concrete requires an industrial robotic arm and—in the case of “DE|stress”—big sandboxes.

Battaglia programmed the robot with digital computer-aided design files of his design. First, the robot used a bit on the end of the arm to rout an impression into the sand, forming the cast. Then, Battaglia placed a hand-welded rebar frame into the impression for added strength.

Finally, he fitted the robot with a printer head, and it squeezed out layer after layer of a special mortar, almost like toothpaste from a tube. The mortar, developed by material scientists at Laticrete, filled the impression and encased the rebar until the panel was complete.

As the name suggests, additive manufacturing lets the fabricator add cement only where it is necessary.

This is how Battaglia’s structure allows natural light and air to move through the project. Those holes represent areas where concrete would have served little structural purpose. As a result, the panels are lighter and easier to handle, material costs are lower, and the structure has a lower carbon footprint. The holes also add ornamentation to structural form, he said.

Will entire buildings be manufactured using 3D printing? Probably not, or at least not in the foreseeable future, Battaglia said. But the technology has the potential to change the way elements of buildings are fabricated.

Europe has begun to embrace 3D printing in architecture, and Battaglia has presented his research in Zurich.

The building industry in North America, on the other hand, has been slower to respond. The industry can be nervous about emerging technologies due to liability concerns, even if the old ways have obvious limitations, Gray said.

Battaglia repeated the fabrication process in the basement of the CAP building until all his panels were complete. Fabricating with help from a robot saves an immense amount of time compared to completing the same design by hand. Even so, the amount of time Battaglia invested supervising the fabrication was almost mind-boggling.

He estimated he spent about 80-100 hours a week inside the CAP building from May to August.

Once fabrication was complete, Battaglia moved panels by the truckload to Columbus for final assembly.

“Every piece is numbered,” Battaglia said.

Embracing experimentation

During assembly, the panels on “DE|stress” were held in place by temporary wooden scaffolding. The idea was that the wood would bear the weight of the structure until the last keystone panel could be dropped into place.

Then, Battaglia would remove the scaffolding and compression would keep the structure from falling.

The pieces didn’t fit together as perfectly in real life as they did in his design. On several edges, excess concrete that formed during fabrication got in the way of clean, tight joints.

“Something goes from design, and it looks perfect, and then you have to deal with these improvisations,” explained architecture Professor Pam Harwood, who teaches with Battaglia. “There’s always reality you have to deal with.”

The researcher and his jobsite crew of graduate students and colleagues used old-fashioned muscle to chisel the panels into shape.

“Since the research is so new, we had to work out details we didn’t expect to find,” he said.

Battaglia wrapped up the project in early October. It remained on site until December 1, when Exhibit Columbus ended. Then, Battaglia disassembled “DE|stress” and sent it to the New Haven, Connecticut, headquarters of Laticrete, a material sponsor for the project, where it is on permanent display.

Battaglia’s heartfelt conviction that automation technology can breathe life into our built environment prevailed.

No miracle required.