Reversible Concrete Allows for Easy Removal

Reversible concrete structure

Yes, you read the title correctly – reversible concrete! It seems like an oxymoron – concrete is known for its stability and strength, and its permanence. Well, not anymore! Last October at the Chicago Architecture Biennial, Self-Assembly Lab at MIT and Gramazio Kohler Research of ETH Zurich showed off a process that might finally one-up concrete, using only a 3-D printing extruder, rocks, string, and smart design.

Reversible concrete held together by stringThe short, unscientific version is that the rocks are bound together by the string into whatever shape is required. Dismantling is easy – just pull the string out.

By jamming rocks together with algorithmically placed string, the team created an aesthetically pleasing 13-foot-tall column for the show. “We are using a similar technique to powder-based printing,” Skylar Tibbits explains to The Creators Project. “There is a container, material is deposited layer by layer and a binder, (in this case the string), is applied to each layer in the specific pattern of the slice.”

3-D extruder makes reversible concrete
3-D extruder makes reversible concrete

“The ability to digitally fabricate, disassemble, and reassemble structures with no material losses changes the paradigm of architecture as well as the view of permanent / temporary architecture,” says installation project lead Andreas Thoma of Gramazio Kohler Research.

The idea started in 2012, when Chicago University professor Dr. Heinrich Jaeger hosted a meeting of great minds from the fields of architecture, physics, and the material sciences to see how they might practically employ the “jamming phenomenon,” which is what happens on a physical level when you cram a bunch of stuff into one spot. The result is “a step towards an alternative to concrete,” says Thoma.

One can only imagine the future uses for this type of material: buildings that can change shape based on occupancy needs, true “living structures;” roads and highways that heal themselves; and who knows what they will think of next.

Source and Photos: The Creators Project, Gramazio Kohler Research, ETH Zurich, and Self-Assembly Lab, MIT, 2015