Researchers at the University of Pennsylvania have developed a groundbreaking 3D printed concrete that not only reduces material usage but also actively captures carbon dioxide from the atmosphere. The innovation, which combines design, engineering, and materials science, introduces a bio-infused composite that has the potential to significantly lower the environmental footprint of concrete—one of the most carbon-intensive building materials in the world.

Diatomaceous Earth: A Fossil Material with a Future

The key ingredient in this novel concrete is diatomaceous earth (DE), a naturally occurring, silica-based material derived from fossilized microscopic algae. DE’s high porosity and sponge-like structure make it exceptionally effective for both structural performance and carbon absorption. When used in 3D printing, it enhances both the printability and strength of the material, countering the usual trade-off between porosity and compressive strength.

By integrating DE into a custom concrete mix, the researchers achieved up to 142% higher CO₂ uptake than traditional concrete. Remarkably, the printed material retained 90% of the compressive strength of standard concrete blocks while using 68% less material and increasing the surface-area-to-volume ratio by over 500%.

Advanced Geometries Inspired by Nature

The project also introduces advanced geometries based on triply periodic minimal surfaces (TPMS)—forms commonly found in coral reefs and bones. These complex, continuous structures are prized for maximizing surface area while minimizing mass, making them ideal for both structural efficiency and carbon capture. Using polyhedral graphic statics, the team optimised the internal force distribution and incorporated post-tensioning cables to further enhance stability.

Applications in Architecture and Marine Environments

This sustainable concrete innovation has broad potential across architecture, interior systems, and infrastructure. The lightweight, high-performance material is suitable for structural elements such as floors, façades, and load-bearing panels, while its porous, eco-compatible structure also makes it ideal for marine applications such as artificial reefs, oyster beds, and coral platforms.

Researchers are now exploring the use of magnesium-based binders and other cement alternatives, aiming for formulations that rely entirely on biobased or recycled materials.

Toward Carbon-Negative Construction

This research represents a significant step toward carbon-negative construction materials, aligning with circular economy principles and the global push for low-carbon architecture. By rethinking both the material and its structural logic, the project opens up new possibilities for designers and architects seeking sustainable innovation in the built environment.

Source: University of Pennsylvania