WSU researchers turn waste into construction materials

WSU researcher loading drywall into an industrial grinding machine.

PULLMAN, Wash. — In the United States, more demolition and construction waste gets sent to the landfill than our everyday solid waste.

According to researchers, the only way drywall gets recycled right now is for it to be turned into fertilizer. Because most of eastern Washington is agricultural land, that drywall ends up here – and even then, only about 10-15 percent of it gets used.

Innovators will tell you their goal is to solve problems and fulfill needs.

A team of researchers in Pullman are finding a new solution for that wasted drywall. One, that is more eco-friendly and less wasteful. They created a drywall waste block (DWB). It’s exactly how it sounds – a solid brick made up of old drywall. It looks like any regular cement block you buy at the store.

WSU researchers David Drake and Taiji Miyasaki are the minds behind the project.

They blend up the drywall, and send it right into what looks like a giant kitchen blender for around fifteen minutes. From there, they send it into a machine to be molded into the shape of a block.

“Everybody knows there’s a plastics problem. Everybody knows that there is a big garbage patch somewhere in the Pacific [Ocean] that is full of plastic, and we need to do something about that,” Drake said.

As it turns out, plastic is just one of our environmental concerns.

“The fact is, you get about 10 million tons in the U.S. of drywall waste, goes to the landfill every year,” Drake said.

Instead of adding to those numbers, thanks to researchers, we can turn it into something valuable and more efficient than what’s on the market.

Drake and Miyasaki also came up with a foamed drywall that’s more flame resistant than your average polystyrene foam insulation.

“We’ve got a layer of plastic, Styrofoam material. You’ve got some mesh, you’ve got some stucco on the outside. This would go on the outside of a building,” Drake said. “The problem is, no matter how much fire retardant you put into this – you still have a plastic material that wants to catch on fire.”

When that plastic material starts burning in a building setting, it creates a chimney effect. Drake said their foamed drywall material takes around two and a half hours to burn through.

“I can just sit there. Hold a torch on it, with my hand right behind it. Obviously, I would never try this with a hunk of Styrofoam. It would burn right through, and I would have a hand full of plastic,” Drake said.

Now that they’ve finalized the product properties, they said their next step is to talk to construction companies about how they can tailor these blocks to building projects. Researchers hope a
manufacturer will license their products and start using them to build within the next two years.