What is the link between 3D printed glass and architecture? MIT researchers have given the answer.
September 30, 2024 According to the Resource Library, a research team from the Massachusetts Institute of Technology (MIT) recently invented a glass block that can be used for 3D printing and has compressive strength comparable to that of concrete bricks. The relevant research results were published in the journal Glass Structure and Engineering.
The new bricks are made from recycled glass and are shaped into a figure 8 shape, suitable for modular building systems similar to Lego bricks. Even if the building is demolished or dismantled, the glass blocks can be used again and again. Demonstrating high levels of sustainability and versatility, the construction industry refers to this design concept as “circular architecture”.
“Glass is a highly recyclable material,” said Kaitlyn Becker, an assistant professor in MIT’s department of mechanical engineering and co-author of the research paper. “We make it into bricks, and when the life of the building structure is over, we make it into bricks. In the future, it can be dismantled and reassembled in new building structures, or placed directly in a 3D printer to create new components with completely different shapes. This process is exactly what we envision for sustainable and circular building materials.
Glass blocks as building materials break preconceived ideas
The construction sector produces large amounts of greenhouse gas emissions during the production of materials, construction and final demolition, which has a huge impact on the environment. This environmental burden, known as “embodied carbon,” makes the construction sector one of the largest sources of greenhouse gas emissions and a target area for sustainability reforms.
In order to significantly reduce carbon emissions in the construction industry, MIT researchers chose glass as a research material because glass has the characteristics of recycling and reuse. Although they admit it’s a bit “counter-intuitive” to think of glass as a building material, as people generally associate glass products with their fragility.
The team worked with MIT startup Evenline to use its latest glass 3D printer, the G3DP3. This device is equipped with a glass melting furnace capable of melting waste glass into a 3D printable state. Eventually, the raw glass is printed into 3D glass blocks, which can be built layer by layer into any desired shape.
Glass blocks: fit together easily, with compressive strength comparable to that of concrete
For this project, the team chose a figure-eight design because it facilitates modular transformation and can easily fit together like Lego bricks. This design can constrain the shape of the bricks very well while still allowing them to be assembled into curved walls.
When creating the first generation of 3D printed glass blocks, researchers chose soda lime glass, a material commonly used for blown glass. Each brick has a pair of cylindrical projections on top, allowing it to be assembled into different shapes, like Lego bricks.
During the printing process, the team added cushioning material between layers of glass blocks to prevent scratches or cracks. This cushioning material can be removed when the building is demolished, allowing the original glass to be melted and made into new bricks or other products.
After printing the first batch of glass blocks, the research team placed them in an industrial hydraulic press for compression testing until the bricks cracked. Test results show that the strongest glass blocks, including those with individual “interlocking structures” at the bottom, can withstand pressures similar to concrete bricks. This means that this new type of glass block is feasible in sustainable construction projects.
To test the feasibility of their 3D printed glass blocks, the research team printed enough interlocking bricks to construct a curved “demonstration” wall in MIT’s Killian Court, made entirely of interlocking glass blocks. . Next, the team plans to build on lessons learned from the demonstration wall construction and assembly process to attempt to construct larger, more complex, self-supporting glass block building structures.
