Thermal performance of a novel masonry block made from recycled gypsum drywall waste

Primary author: David Drake
Co-author(s): Taiji Miyasaka

Primary college/unit: Voiland College of Engineering and Architecture
Campus: Pullman


Developing new product applications for waste recycled from building construction and demolition (C&D) provides environmental and economic benefits. However, challenges remain for recycling certain low-value C&D materials, such as gypsum drywall waste, which is banned from landfilling in some areas due to hydrogen sulfide emissions during decay. The gypsum and paper components in drywall have low thermal conductivity relative to concrete and brick, suggesting a novel insulative masonry block system made from recycled gypsum drywall waste could have higher thermal performance than conventional concrete masonry units (CMU). The authors have developed such a system, referred to as Drywall Waste Block (DWB), and have previously published investigations of DWB engineering properties including compressive strength, water absorption, bulk density, and thermal conductivity. This paper describes investigation of resistance to heat flow of a reinforced DWB wall assembly, using a calibrated hot box apparatus as specified in ASTM C1363-11. The hot box apparatus was designed and fabricated as a cost-effective alternative to commercially testing services, affording rapid iteration during the research and development phase of novel building products made from unconventional materials. Some aspects of the apparatus design, fabrication, and characterization are discussed. Thermal performance of the DWB wall relative to a comparable CMU wall is discussed, as are areas for further research.