Combining Concrete and Wood

(Swiss National Science Foundation SNSF, July 05, 2017)

Swiss researchers have now developed a radical approach to combining wood and concrete: they are fabricating a load-bearing concrete which itself consists largely of wood. In many blends, the volume fraction of the wood is over 50 percent. The main difference from classical concrete is that the gravel and sand content is replaced with finely ground wood. In other words, sawdust rather than small stones is mixed in with the cement. Thanks to the high wood content, the new building materials show good flame retardance and act as thermal insulation. They weigh at most half of what normal concrete weighs – the lightest of them even float. Moreover, as the materials are based largely on renewable resources, after dismantling they can be reused as a source of heat and electricity. The wood content can be burnt in waste incineration, although for everyday use it conforms to fire protection standards.