3D printed glass bricks provide a window of opportunity

3D printing is an area of technology that was theorised in the 1940s with the earliest 3D printer prototype created in the early 1980s. Since then, the world of 3D printing has evolved hugely. No longer is it a small scale endeavour whereby material is printed layer by layer; with the introduction of additive manufacturing, where objects are created by adding materials to the construction, the technology and what it can achieve across the board has boomed.

One such area this technology is being deployed is in the construction industry. Inspired by glassblowing techniques, engineers from MIT have integrated construction and design to develop 3D printed glass bricks.

It is hoped that these bricks could form the foundations for a shift towards a circular economy in the construction industry.

Printed glass bricks

The concept of 3D printed glass bricks is cemented in a need to create strong, reusable building components that can be integrated into architectural applications, such as glass walls or partitions.

The design and process integrate glassblowing techniques with 3D printing technology, and the result is bricks in the shape of a figure-of-eight that interlock a bit like a LEGO block and are multilayered. These features allow the bricks to lock together without the need for adhesives, which makes them easy to assemble and then disassemble again for future use.

Initial testing indicates that the bricks can withstand pressures comparable to traditional concrete blocks, which means that they may become a practical option for structural applications. With a wider goal of reducing emissions in the construction industry, these glass bricks could become an important part of reducing waste within the construction industry, providing a recyclable and repurposable alternative to traditional building materials.

The circular economy

According to the International Energy Agency (IEA), the construction industry contributes to approximately 39% of global carbon emissions, and as operational efficiencies in buildings improve, attention has turned towards reducing embodied carbon – the emissions associated with each process of the construction process such as the production, transportation, and assembly of building materials.

By adopting a circular approach, MIT’s glass bricks offer a possible way to reduce the need for manufacturing new materials as they can be printed, and then when they aren’t needed any more, they can be disassembled and melted back into their molten form, ready to be used for another purpose, thus creating a closed-loop system – the circular economy.

This construct works as long as the glass remains uncontaminated. As long as the material is viable, it can be recycled indefinitely.

According to the team, glass has been widely recognised for its high recyclability and favourable structural properties, but its use in structural building components is still a developing field. So MIT’s research team is tempering the boundaries of what glass can achieve by presenting the potential for entirely glass-based, transparent masonry systems.

The technology: G3DP3 printer

The technology driving the production of these glass bricks is a Glass 3D Printer 3 (G3DP3), which is capable of printing molten glass – currently the team are using soda-lime glass which is a common material in traditional glassblowing studios. The printer is paired with a furnace that melts recycled glass bottles into a printable molten state, and is then deposited in layers to form the brick structures.

The G3DP3 printer can print objects up to 32.5 x 32.5 x 38cm, making it suitable for producing full-size masonry units, moreover, the printer is able to handle complex geometries without the need for expensive moulds.

The future of glass bricks in construction

In addition to their role in standard construction projects, these glass bricks could be used to create visually striking facades, light-transmitting walls, and environmentally friendly building materials that reduce the industry’s reliance on concrete and steel.

While the use of glass bricks in load-bearing walls and other structural applications is still under development, their demonstrated strength and resilience means that they could become a key material in future construction efforts.