What do you get if you cross sawdust with 3D printing? Sustainable buildings!
12 September 2023
Combining upcycled sawdust with 3D printing could revolutionise construction with fully biodegradable, reusable and recyclable building materials.
Image: Tharanesh Varadharajan, Zachary Keller, Muhammad Dayyem Khan
Researchers have developed a new sustainable material to replace the wasteful concrete formwork traditionally used across the construction industry.
The base of this material is upcycled sawdust. Millions of tons of sawdust waste are created each year from the 15 billion cut trees and often burned or dumped in landfills left to contribute to environmental pollution.
The BioMatters team at the University of Michigan is making productive use of this readily available resource. Currently, they are using sawdust created at the Fabrication Laboratory at Taubman.
“We have made a recyclable, all-natural biomaterial which is made out of sawdust. Other sawdust-based solutions are using other petroleum-based polymers – we use biopolymers which are completely decomposable,” says Muhammad Dayyem Khan, Researcher at the DART laboratory.
“And the biggest thing is it’s very easy to recycle and reuse.”
Led by DART director Mania Aghaei Meibodi, along with researchers Tharanesh Varadharajan, Zachary Keller, and Khan, the team proposes a novel method that couples robotic 3D printing of the wood-based material with incremental set-on-demand concrete casting to create zero-waste freeform concrete structures.
The 3D-printed wood formwork shapes the concrete during casting, and the concrete stabilises the wood to prevent deformation.
Once the concrete cures, the formwork is removed and fully recycled by grinding and rehydrating the material with water, resulting in a nearly zero-waste formwork solution.
“When the sawdust decomposes, it is producing fatty acids, lignin, which causes toxicity in water. Once it starts contaminating water, it has its effects on smaller wildlife, microbes, and a broad range of organisms. And with sawdust being extremely flammable, its potential contribution to wildfires is very high,” Khan says.
This solution directly addresses significant waste and pollution contributions of the concrete industry where formwork constitutes 40 percent of concrete construction expenses.
Traditionally made from wood and discarded once deformed, formwork adds to the negative environmental impact of concrete construction.
“The amount of sawdust that is being produced out there – it is a huge chunk of material that is just being dumped or burned,” Khan says.
“So, rather than burning it up and generating more CO2 emissions, it is so much better that we make it into a material that is actually capable of being used again and again.”
This research is paving the way for sustainable construction practices that reduce waste, pollution, and resource consumption in the concrete industry.
By upcycling this unused byproduct of the wood industry, the project represents a significant step toward environmentally friendly and efficient concrete construction methods.