MIT reuses tree waste as structural joints

Thanks to a construction technique developed by researchers at the Massachusetts Institute of Technology, branch bifurcations – usually a part of the tree trunk that is discarded because it is difficult to use in canonical processing – could be reused as structural joints. These Y-shaped nodes are reused in the research team’s prototypes as a connection between the horizontal and vertical structural system.

The first step in the team’s work is to catalogue a selection of tree bifurcations in a digital library. These scans capture the relative geometry and orientation of the branches, which determine the internal fibre orientation of a fork and thus its strength.

The second step is to match these elements to the actual nodes of a given architectural design. This is achieved through algorithms that evaluate the correspondence between the shape of a particular fork and a particular node, and then adjust the overall fork distribution to make the most efficient use of the inventory.

Next, designers can play with the shape of the structure, reusing the algorithm on the new shape. Once the design is finalized, the fourth stage is to cut the bifurcations of the tree as much as possible to remove the bark and make the joint fit into the assigned node, again using an automated procedure. In the final stage, the structure is manually assembled as a jigsaw puzzle.

Offering a substitute for high-strength but emission-intensive virgin materials such as steel, the system could have a major impact on the environmental impact of the construction market. Created by the Digital Structures research group, the element has already been used to install a demonstration structure on the university's campus, while a larger pavilion is in the pipeline.

Opening image: MIT Digital Structures. Photo Felix Amtsberg