What happens if the green concrete keys grow in the ocean rather than mined from Earth?
Researchers at the University of Washington and Microsoft have developed a new type of low-carbon concrete using powdered seaweed.
By mixing dry green algae and cement, the team created a formulation that has a 21% lower chance of global warming, while maintaining the structural strength of the material.
Their findings highlight that combining natural materials with machine learning tools can speed up searching for more sustainable building solutions.
Seaweed meets cement science
Cement, an important binder in concrete, is one of the most pollutants in the world. He is responsible for up to 10% of all joint emissions worldwide, mainly through the use of fossil fuels and the carbon release chemical process known as calcification.
When you produce one kilogram of cement, you will produce almost one kilogram of Co2. In contrast, seaweed acts as a carbon sink during its growth, making it a promising alternative additive.
“Cement is everywhere – it's the backbone of modern infrastructure – but it comes with enormous climate costs,” said Eleferia Lemeli, UW assistant professor of materials science and engineering.
“What makes this work exciting is that it shows that rich photosynthetic materials, such as green seaweed, can be incorporated into cement to reduce emissions without the need for costly processing or sacrifices of performance.”
Usually, each concrete sample requires several weeks to be treated before testing, so once it arrives at the right mix of materials it requires trial and error.
To overcome that bottleneck, the team used a custom machine learning model that predicts the optimal seaweed cement blend. By bringing the test results back into the system, they hone their formulation in just 28 days. This is Roumeli's estimation process, which would otherwise have taken five years.
“Machine learning has been essential to dramatically shortening processes, especially here, because we're introducing a whole new material into cement,” Lumeli said.
Low carbon concrete
Unlike other cement additives that require complex treatments and manufacturing steps, green seaweed can be used in dry, powdered form without any expensive treatments.
This makes it a particularly accessible option for globally scaling low-carbon concrete production.
By combining this natural material with machine learning, researchers envision a system that allows producers to quickly develop customized cement formulations tailored to local resources and environmental conditions, whether they contain a variety of algae, food waste, or other bio-based additives.
The team is currently looking to explore how different seaweed compositions and structures affect cement performance.
Their broader goal is to expand the method to other algae and food waste, and enable producers around the world to develop local, sustainable cement alternatives by adding machine learning to accelerate the optimization process.
“Combining natural materials like algae with modern data tools allows us to localize production, reduce emissions and move faster towards faster infrastructure,” Lemeli said.
“This is an exciting step towards a new generation of sustainable building materials.”
Findings funded by Microsoft Research have been published in the journal Case.
