The 3D printing firm is partnering with Atlanta-based general contractor FMGI and Little Rock, Ark.-based equipment rental firm Hugg & Haul on the Walmart projects, which will primarily be auxiliary online pickup buildings at existing Supercenters. Alquist developed the techniques to deliver these structures with its contractor and equipment supplier over the two pilot projects it did for Walmart, which taught them all key lessons on 3D printing buildings for the commercial market.

Related: 3D Printed Concrete Finds Its Footing

“The 8,000-sq-ft addition we did for Walmart in Athens, Tenn., ... was the largest 3D-printed building [of its type] in the world,” says Patrick Callahan, CEO, Alquist 3D. “There were a lot of trials and tribulations in that one, since it was the first of its kind—a lot of learning for (us) and our GC partner.”

The second project, a more modest 5,000-sq-ft addition to a Walmart in Owens Crossroads, Ala., saw tremendous savings in the schedule, with the whole building going up in seven days with four workers running two printer robots.

“We shaved three weeks off the schedule there and saved them some money,” recalls Callahan. “And we thought ‘whoa, this could be something,’ and started discussions with [Walmart] about scaling this up.”

Operators keep an eye on the slump during the Athens, Tenn., building print. Photo courtesy Alquist 3D

While many 3D printing firms are regionally limited by having their own robots and staff going out to sites, Alquist is preparing for nationwide operations. Contractor employees are trained to run the 3D-printing robots, which consist of six-axs robotic arms with concrete-extruding nozzles. 

Robots are leased to contractors by Alquist, which also develops and supports the software that drives them. It has worked out a nationwide deal with Sika to provide the specific ready-mix concrete it needs. In order to avoid questions about structural stability, the concrete printed by Alquist on the first two Walmart pilots had a requirement of 7,500 psi, more than double of traditional portland cement. 

Callahan says Alquist works to greatly exceed local building codes for masonry. The Athen, Tenn., project taught the team a great deal about performance of their printer, including new techniques on how to extrude concrete onto CMU block and maintain structural strength.

The Alquist robot, moving on a rail system set up on site, has a vertical reach of 20 ft, which can be extended further with the use of platforms for the rails. Callahan says each robot can fit into a standard trailer pulled by a pickup truck, with about an hour needed to set it up or break it down. Multiple robots can work in concert on a structure by working off the same design file, saving time. “It’s a big change from the big gantry-style robots you’d see in the past,” he says. “Those could be very expensive and were hard to manipulate, with longer set up times.”

Licensed to 3D Print

User friendliness has been a goal for the Alquist team, which would prefer to step back and let contractors 3D print the structures themselves. “Our model for scaling this up is that we focus on being a tech company,” says Callahan. “We’re doing the 3D printing technology, updating our own robotics platform, forming the partnerships with our material partners. We have license agreements with all of our GCs and suppliers, and those can be different configurations depending on the region or sector of the industry.”

Alquist isn’t locked into one business model, and is willing to sell, lease or rent its robots out, and can provide training for contractors to run them independently. FMGI has signed on to build most of the planned Walmart projects, with support from Alquist.

“Prior to collaborating with Alquist 3D on the Walmart project in Athens, Tenn., FMGI had limited experience with 3D printing technology,” says Babak Zareiyan, FMGI’s director of innovation and technology. “Nevertheless, FMGI adopted a progressive strategy by consulting leading specialists in concrete 3D printing, which enabled the successful start of its innovation and tech- nology division.” While Zareiyan doesn’t see 3D printing replacing traditional CMU block work, he tells ENR it’s a “valuable alternative.”

“What drew us to Alquist was how practical this technology really is—it’s faster to mobilize, cleaner on-site and delivers consistent quality in every print,” said FMGI President and CEO Darin Ross in a press statement. “For us, this partnership is about transforming how large-scale projects actually get done.”

The deal with Hugg & Haul, which has locations across Arkansas, Louisiana and Mississippi, will also allow Alquist to outsource some of the maintenance and fleet management work for the robots as they go out to sites, explains Callahan. “It means they can lease or rent the robots out, but also be ready to do maintenance across the country if a piece of our equipment goes down.” The need for support staff is one hurdle that keeps many 3D printing firms from scaling up, he notes, and partnering with local equipment firms can address that.

“In 3D printing, if we can keep the robots going, the projects will go faster,” he adds.