Researchers at the University of Washington and Microsoft have developed a promising low-carbon concrete by integrating powdered seaweed into traditional cement. The innovation could help architects, landscape designers, and urban planners significantly reduce the environmental impact of building materials.

Concrete’s Environmental Cost

Concrete is the world’s most widely used construction material after water. However, its main ingredient—cement—is responsible for up to 10% of global CO₂ emissions. These emissions come primarily from fossil fuel combustion and the chemical reaction known as calcination during cement production.

Seaweed, on the other hand, is a renewable resource and a natural carbon sink. As it grows, it absorbs CO₂ from the atmosphere. The research team discovered that dried, powdered Ulva (a common green seaweed) can replace 5% of the cement content in concrete. This substitution reduces the material’s global warming potential by 21%, all without compromising strength or durability.

Fast-Tracked Innovation with AI

Traditionally, developing new cement formulations can take years, due to the lengthy curing time needed before testing. To accelerate this process, the team used machine learning. They trained a custom model on 24 early cement mixtures and used its predictions to refine new formulations. Each round of testing improved the model, and in just 28 days, the researchers identified an optimal blend that met compressive strength standards.

Toward Sustainable Architecture

This seaweed-enhanced concrete supports several sustainability goals. It lowers carbon emissions, uses a naturally abundant material, and avoids energy-intensive processing. The researchers aim to expand the work by experimenting with other types of algae and even food waste. The ultimate goal is to enable the local production of low-impact cement alternatives worldwide.

For architects and designers working toward greener infrastructure, this bio-based material offers a practical step forward. It demonstrates how nature-based solutions and digital technologies can intersect to drive innovation in the built environment.

Source & photo: University of Washington