The BioMatters team at the University of Michigan in Ann Arbour has created a totally biodegradable, reusable, and recyclable, zero-waste material to replace standard concrete formwork in the building industry. This material is made from recycled sawdust, specifically, millions of tonnes of sawdust waste are generated each year.
The Taubman College of Architecture and Urban Planning’s BioMatters team, in collaboration with the Digital Architecture Research & Technology (DART) Laboratory, is making good use of this easily available resource. They are now using sawdust produced at Taubman’s fabrication facility.
The team was led by DART director Mania Aghaei Meibodi and researchers Tharanesh Varadharajan, Zachary Keller, and Khan. They propose a novel method for creating zero-waste freeform concrete structures that combines robotic 3-D printing of wood-based material with incremental set-on-demand concrete casting. Furthermore, the 3-D-printed wood formwork shapes the concrete during casting. The concrete stabilises the wood to prevent deformation.
“When sawdust decomposes, it produces fatty acids (lignin), which cause water toxicity.” When it contaminates water, it affects smaller animals, microorganisms, and a wide spectrum of creatures. And, because sawdust is incredibly combustible, it has a large potential impact to wildfires,” Khan explains.
More on how the zero-waste material by University of Michigan is made
Once the concrete has cured, the formwork is removed and recycled completely by grinding and rehydrating the material with water. This results in a practically zero-waste formwork solution. Additionally, the method immediately targets the concrete industry’s considerable waste and pollution concerns. Formwork accounts for 40% of concrete building costs. It contributes to the negative environmental effect of concrete building.
“We created a recyclable, all-natural biomaterial out of sawdust,” explains Muhammad Dayyem Khan, a DART laboratory researcher. “Other sawdust-based solutions use petroleum-based polymers — we use biopolymers that are completely decomposable, and the best part is that it’s very easy to recycle and reuse.”