Washington State University researchers develop bricks made of C&D debris

WSU team Jose Becerra, David Drake and Jacob Sauer (left to right) display brick they have made from drywall construction debris.

A team at Washington State University (WSU), Pullman, Washington, has developed a building system made from low-value construction debris that it hopes can reduce waste while creating affordable housing.

A prototype structure featuring the drywall-based bricks will be displayed as part of the Make/Do: A History of Creative Reuse exhibit starting July 14 at the Washington State History Museum in Tacoma. The exhibit is focused on the history of creative recycling and reuse.

Construction and demolition debris is a growing problem in the United States, WSU says. In 2014, contractors disposed of 534 million tons of debris, tripling since 2003. Drywall, also known as gypsum board or sheetrock, is an interior wall covering that is cost effective but wasteful to install, WSU says. Building a 2,000 square-foot home generates more than a ton of drywall scrap.

While there have been increasing efforts to recycle many construction materials, low-value drywall makes up nearly half of unrecycled construction debris. Furthermore, the college says, when it’s put into landfills, soil bacteria decompose the gypsum and produce a noxious gas.

The researchers, including Taiji Miyasaka, professor in the School of Design and Construction, David Drake, adjunct faculty in the School of Design and Construction and Robert Richards, a professor in the School of Mechanical and Materials Engineering began developing the drywall blocks in 2017 with a grant from the American Institute of Architects, Washington. They also recently received an Amazon Catalyst grant to move the project from laboratory scale to a demonstration structure.

The blocks are made from 80 percent drywall waste and a binder made from industrial byproducts. They are waterproof and lighter than earth blocks, bricks or concrete blocks, Miyasaka says. The researchers are partnering with local contractors to get the debris, and architecture students are using a press to build the blocks, which look like masonry bricks.

“The bricks are similar to adobe or compress earth blocks,” Drake says. “But our blocks are superior, especially for insulation.”

In the next year, the researchers will be testing the blocks to meet building, seismic and fire codes. They also aim to build a 160 square-foot demonstration structure.

For the upcoming exhibit, the team will also exhibit several structures that they have built out of other common materials, including magazines, paper and garbage bags.