Cosmos
Cosmos is a quarterly science magazine. We aim to inspire curiosity in ‘The Science of Everything’ and make the world of science accessible to everyone.
By Cosmos
Best put your stones away, because the future of sustainable construction could mean living in glass houses.
Engineers at Massachusetts Institute of Technology (MIT) in the US have developed a new kind of masonry made from 3D-printed, recycled glass.
The bricks are the shape of a figure 8 and are designed to interlock, kind of like LEGO, for use in the facades and internal walls of buildings.
And they aren’t designed to be tossed into landfill at the end of the building’s lifecycle.
“Glass is a highly recyclable material,” says Kaitlyn Becker, assistant professor of mechanical engineering at MIT and co-author of a study detailing the glass brick design in the journal Glass Structures and Engineering.
“We’re taking glass and turning it into masonry that, at the end of a structure’s life, can be disassembled and reassembled into a new structure, or can be stuck back into the printer and turned into a completely different shape.
“All this builds into our idea of a sustainable, circular building material.”
Circular construction aims to reuse and repurpose a building’s materials. This minimises the manufacturing of new materials and reduces the greenhouse gas emissions associated with the industry, which accounts for 39% of global energy‐related emissions.
The team used a 3D printer made by MIT spinoff Evenline, which pairs with a furnace to melt crushed glass bottles into a molten, printable form that it then deposits in layered patterns.
The resulting bricks have 2 round pegs to allow them to interlock and assemble into larger structures, such as a curved wall.
The researchers tested the mechanical strength in an industrial hydraulic press, which squeezed the bricks until they began to fracture.
They found that the strongest bricks were able to withstand pressures comparable to those of concrete blocks. These were made from printed glass with a separately manufactured interlocking feature that attached to the bottom of the brick.
“Glass is a complicated material. The interlocking elements, made from a different material, showed the most promise at this stage,” says Becker.
Next, they aim to build progressively bigger, self-supporting glass structures.
“We have more understanding of what the material’s limits are, and how to scale,” says Michael Stern, founder and director of Evenline and co-author on the study.
“We’re thinking of stepping stones to buildings and want to start with something like a pavilion — a temporary structure that humans can interact with, and that you could then reconfigure into a second design. And you could imagine that these blocks could go through a lot of lives.”
Perhaps they’ll be used to construct the next Crystal Palace?
