Unmet Need: New use for construction & demolition gypsum drywall
Construction of an average 2000 square foot home produces more than a ton of gypsum wallboard waste. Gypsum wallboard waste is a low-value material, typically disposed of in landfills. Landfill disposal presents a significant problem due to anaerobic soil bacteria consuming gypsum and producing hydrogen sulphide (“rotten-egg”) gas, which is toxic in high concentrations. Furthermore, some landfills no longer accept gypsum wallboard waste.
The Technology: Masonry blocks using recycled gypsum wallboard
Researchers at Washington State University’s School of Design and Construction have developed a method to create and a composition of load bearing masonry units made of recycled gypsum wallboard (called gypsum wallboard waste blocks or “GWWBs”). GWWBs not only have the potential to divert a significant amount of gypsum wallboard waste from landfills, but they also possess more predictable properties compared to other masonry units such as adobe blocks and compressed earth blocks (CEB) made with local soil. For example, GWWBs have a higher compressive strength and allow simple seismic reinforcement compared to traditional adobe blocks. Moreover, GWWBs have higher water resistance versus unstabilized CEB or adobe blocks and cost much less to produce compared to light-frame wood construction or concrete masonry unit construction (CMU). GWWB also possess a higher r-value than adobe, CEB or CMU construction, allowing code-conforming wall assemblies that do not require supplemental insulation. They also possess a higher thermal mass compared to light-frame wood construction and require less skill for construction than light frame wood or CMU construction. They are easier to modify in terms of cutting, drilling, etc., versus other concrete construction and have a high fire resistance. Finally, since traditional adobe block and CEBs have been used for code-conforming construction of wall-assemblies and are treated as adobe masonry under International Building Code (IBC), GWWBs will fall under the same provisions of the IBC. The composition and methods developed by the researchers allow for on-site production of GWWBs that are well suited to small scale owner-builder and community building projects.
• Load-bearing masonry units
• GWWBs have a higher compressive strength and allow simple seismic reinforcement compared to traditional adobe blocks
• GWWB possess a higher r-value than adobe, CEB or CMU construction
• Easier to modify in terms of cutting, drilling, etc., versus other concrete construction and have a high fire resistance
Provisional patent application filed