Swiss researchers may have found a radical way to make concrete greener, lighter and easier to recycle – by manufacturing it from wood.
Researchers from the Swiss National Research Programme, Resource Wood, have discovered a way to fabricate a load-bearing concrete that can contain more than 50 per cent wood content.
While cement-bonded wood products are nothing new, Dr Daia Zwicky, head of the Institute for Building and Environmental Technologies at the School of Engineering and Architecture of Fribourg, is working to create a load-bearing product that can be used for a range of construction uses.
The big difference between conventional concrete and this product is that instead of gravel and sand (which is becoming increasingly scarce), sawdust is used.
Working with a team of researchers, Dr Zwicky experimented and tested a variety of blends of wood in combination with a number of additives.
The researchers found the high wood content had a number of benefits, including good flame retardance. The wood content also acts as thermal insulation, and the team’s early stress tests show the materials are suitable for slabs, walls and load-bearing structural elements. It is also suitable for prefabricated units.
The materials are far lighter than conventional concrete, too.
“They weigh at most half of what normal concrete weighs – the lightest of them even float,” Dr Zwicky said.
The materials can also be dismantled at end of life, and the wood content used to generate electricity and heat, he said.
However, don’t expect it to be showing up in our buildings in the immediate future.
“It will take several years before we see the first buildings in which lightweight concrete containing wood plays an integral role in the construction,” Dr Zwicky said.
“The level of knowledge required for widespread application is still too limited.”
The next step for the team is to continue testing and research to establish which of the new materials are suitable for specific applications.