The construction industry is one of the world’s largest sources of carbon emissions.
In 2022, making construction materials such as steel, concrete, and timber produced more than 7% of all global carbon emissions.
But what if many of those materials were never actually needed in the first place?
Researchers at the Massachusetts Institute of Technology (MIT) have developed a new computer-based design method that could dramatically reduce the amount of material needed to build bridges, buildings, and other structures.
In some cases, it could cut material use by as much as 90%, helping lower costs and reduce pollution while still creating safe and strong structures.
The research builds on a design method called topology optimization. This computer technique searches for the most efficient way to place materials inside a structure.
It removes unnecessary material while keeping enough strength to support heavy loads.
The designs created by topology optimization often look unusual, with thin branches and web-like shapes that are very different from traditional buildings and bridges.
Although these designs are highly efficient, they are usually too complicated to build using today’s construction methods. As a result, the technology has mostly been used in research laboratories and for small 3D-printed objects rather than real-world construction projects.
MIT researchers wanted to change that.
They developed a new design framework that allows engineers to control how simple or complex the final structure will be.
Instead of producing designs that are nearly impossible to build, the new system creates practical designs that contractors can realistically construct.
For example, engineers can tell the program how many structural parts are allowed to meet at a single joint, how large the smallest pieces should be, and the minimum angle between connected parts. These limits help produce designs that are easier to manufacture, transport, and assemble on construction sites.
The new system also considers different building materials at the same time. Rather than assuming everything is made from one material, it can decide where steel, timber, or other materials should be used based on their strength, weight, cost, and environmental impact.
For example, steel is extremely strong and works well in areas that carry heavy loads. Timber, on the other hand, usually has a much smaller carbon footprint. The program can combine both materials, using timber wherever possible to reduce emissions while placing steel only where extra strength is needed.
The researchers also improved how the computer handles connections between different parts of a structure. In real construction, connecting beams, cables, and supports safely is often one of the biggest engineering challenges. The new model takes these practical issues into account from the beginning instead of treating them as an afterthought.
To test the system, the team redesigned several truss structures used in bridges and buildings. They also used the Lockport “Upside-Down Bridge” in New York as a case study to see how different design rules changed the final structure. The results showed that adding practical construction limits produced designs that remained highly efficient while being much easier to build.
Although the new method requires more computer power than some older approaches, the researchers were able to run their tests on a standard MacBook Pro. They believe the technology is already practical for many engineering companies.
The team plans to build small-scale versions of their computer-designed structures to confirm that they perform as expected. In the future, they hope to add even more practical design rules so civil engineers can easily use the software in everyday projects.
The researchers believe that many important decisions affecting carbon emissions are made long before construction begins.
By designing buildings and bridges that use only the materials they truly need, engineers could significantly reduce waste, lower costs, and help make the construction industry more sustainable.
