Geomatrix combines the cutting edge with ancient methods
By Bay Stephens
EBS Staff Writer
LIVINGSTON, Mont. – Glass recycling is a hot topic in Montana; few programs process it, so the material populates landfills across the state. However, crushed and cleaned, some glass might get put to use flecking the Roman-like concrete of Livingston-based Geomatrix Inc.
While working as a research assistant at Montana State University in the early 2000s, owner Jon Cross developed a concrete made of recycled materials that was surprisingly strong and very clean. Using fly ash—a byproduct of burning pulverized coal for electricity—and crushed glass, he estimates the substance is 95-98 percent recycled materials before pigment is added for coloration.
“It’s a seriously green, highly sustainable material,” Cross said. His recipe revives ancient methods, such as those of the Romans, who used volcanic ash mixed with a mineral slurry to create concrete structures that still stand today.
“If they could do it then, why can’t we do it now?” Cross said. He toured Italy when he began his research to learn from millennia-old structures like the Pantheon. “It made an impact on me.”
After years of trial and error, Cross learned to control how quickly the fly-ash mixture hardened. The result was a compound that outstripped Portland cement, the material traditionally used to make concrete. Cement as the “glue,” rock or sand is added as the aggregate, creating concrete.
“If you can learn how to control the set, it’s basically a really high-performance concrete, and it’s a waste product,” Cross said. With fly ash from a Billings powerplant, he’s dialed the material to withstand pressure between 10,000 and 15,000 pounds per square inch. Typical concrete is rated for 4,000 pounds per square inch.
And instead of the 28-day curing time of traditional concrete, Cross said that the fly-ash concrete reaches full strength in approximately a week. During his research days, many academics were incredulous that fly-ash concrete could viably substitute Portland cement, yet it’s all Cross has used the past 18 years; the past eight, it’s been the bread and butter of Geomatrix. The company has been sought after for its use of crushed glass as the aggregate because ambers, greens and blues fleck the face of the concrete.
Geomatrix’s concrete work stands in buildings such as the Jake Jabs College of Business and Entrepreneurship at MSU, and the NorthWestern Energy headquarters building in Butte. On a project in Yellowstone National Park, Cross estimates they used 100 tons of crushed glass to make picnic tables, countertops and wall caps.
Recently, Cross and his employee, Joe Spidel, have focused more on residential work. They cast countertops, shower and floor panels, but, with a wealth of construction knowledge between them, they don’t stop at concrete. From cabinets to rebuilding stairs, they’ve done work at homes in Big Sky’s Moonlight Basin, Bozeman, Missoula, Butte and Paradise Valley.
And they haven’t had to go far for fly ash: throughout the past 18 years, a Billings powerplant has supplied all that they need.
“Burning coal is nasty,” Cross said. “And that was the whole attraction for me … they’ve already polluted and they’re just throwing this ash away. If you take that and use it as concrete, you’re not adding any more emissions in the process.”
The same can’t be said of Portland cement.
According to marketplace.org, as much as 10 percent of global carbon dioxide emissions result from the production of Portland cement. Production involves sending raw materials through a 2,700-degree kiln, which can be up to 12 feet in diameter and “longer in many instances than the height of a 40-story building,” according to the Portland Cement Association website. The process is so energy intensive, estimates have been made that every ton of cement yields a ton of carbon dioxide.
Geomatrix used to source crushed glass locally, too, from just down the road, in fact. Livingston’s Solid Waste Department used to crush glass and sell to Cross until they shut down the glass crusher a couple of years ago. After that, Cross bought glass from a Bozeman gravel pit before finally opting for glass out of Denver or Salt Lake City, the final destinations of any glass collected for recycling in Montana.
“We can get glass out of there for the same cost as we can get it from here,” Cross said, noting the additional processing costs of cleaning local glass.
Since they decommissioned their crusher due to the manpower it required and a lack of floor space, glass has been a thorn in the side of Rich Stordalen, the Livingston transfer station foreman.
“I’ve got a mountain of glass that ain’t doing nothing,” Stordalen said.
He estimates that he’s sitting on 250-300 tons of glass. For $60 a ton, he can package and ship it to Momentum Recycling in Salt Lake City, but with the large quantities he receives, he said it’s just not feasible. Instead, he could send it to a landfill for $48 a ton.
Although Cross approached Stordalen about taking over the glass crusher, the costs and strings that the Solid Waste Department attached to it quickly shut down discussion. Stordalen said no one’s come back after seeing the operation cost.
“I just don’t know what to do with glass,” Stordalen said.
Although it would be convenient for Cross to source crushed glass locally, he’s more focused on the other irons he has in the fire. Cross continues to experiment with mixtures, and his current projects are aimed at creating all-natural, mineral-activated geopolymers to use in lieu of Portland cement concrete and fly ash concrete for decorative applications. He’s also ordered a computer numerical control router that will significantly change their capabilities when it comes to making molds for sinks and wall panels.
And whatever projects Cross undertakes next, he intends to keep things clean and green.