A groundbreaking project named *Diamanti* has emerged from the University of Pennsylvania, showcasing a 3D-printed bridge that not only reduces material use but also significantly enhances carbon absorption. This innovative design, which draws inspiration from natural porous structures like bones, aims to tackle the substantial carbon footprint associated with conventional concrete, which contributes approximately 8% of global greenhouse gas emissions.
The *Diamanti* project employs a unique combination of advanced materials and an efficient design methodology. By utilizing a robotic 3D printer, the team is able to create complex, lattice-like patterns with a sustainable concrete mixture. According to Masoud Akbarzadeh, an associate professor of architecture and the project’s director, this approach allows for a reduction of 60% in material usage while maintaining structural strength.
Concrete traditionally absorbs carbon dioxide, with some estimates suggesting up to 30% of its production emissions can be captured over its lifespan. However, the new concrete mixture developed for *Diamanti* captures an impressive 142% more carbon dioxide than standard mixes. This enhancement stems from the incorporation of triply periodic minimal surface (TPMS) structures, mimicking bone architecture, which increases the material’s surface area and, consequently, its ability to absorb carbon.
The *Diamanti* initiative began in 2022, in collaboration with Swiss chemical company Sika and supported by grants from the US Department of Energy. Currently, the team is preparing to build its first full-sized prototype in France.
Challenges in the Cement Industry
Concrete’s strength and durability are crucial for its widespread use. Andrew Minson, director of concrete and sustainable construction at the Global Cement and Concrete Association, notes that the cement industry has made strides in sustainability, reducing carbon emissions per metric ton by 25% since 1990. Despite these efforts, emissions have risen due to increased demand, as reported by the International Energy Agency.
Cement, which serves as a binding agent in concrete, is responsible for a significant portion of these emissions—around 90%. The energy-intensive production process involves heating limestone to high temperatures, releasing carbon dioxide as a byproduct. Experts suggest that substituting certain materials can help mitigate the carbon footprint of cement, with innovative companies developing carbon-negative mixes.
The concrete mixture used in *Diamanti*, engineered by Dr. Shu Yang, incorporates diatomaceous earth, a naturally porous material derived from fossilized algae. This substitution not only enhances carbon absorption but also creates channels that allow carbon dioxide to penetrate the concrete more effectively. Nevertheless, as highlighted by civil engineering expert Du Hongjian, the global production of diatomaceous earth was limited to 2.6 million tons in 2023, raising concerns about its scalability for mass concrete production.
Testing and Future Applications
To ensure the viability of *Diamanti*, the research team has produced a series of prototypes. The initial five-meter-long model demonstrated the concept’s feasibility, followed by a ten-meter version completed with materials provided by Sika Group Switzerland. This larger prototype successfully passed load testing, exceeding expectations, as noted by Akbarzadeh.
Currently on display at the Venice Architecture Biennial, the prototype showcases the potential of 3D printing technology to significantly reduce construction time and material waste. According to Akbarzadeh, this method can cut construction costs by 25% to 30% while also reducing the need for steel by 80%, further lowering emissions associated with traditional construction methods.
The team originally aimed to build the first full-scale bridge in Venice, but regulatory changes prompted them to seek alternative locations. They have since secured approval to construct the bridge in France, with potential sites being considered near the iconic River Seine in Paris.
Beyond bridges, the *Diamanti* team is exploring additional architectural applications, including prefabricated floor systems. While Akbarzadeh acknowledges that this project is not a one-stop solution, he expresses hope that *Diamanti* will open “a whole new world of possibilities” for sustainable concrete construction.
As the *Diamanti* project moves forward, it exemplifies how innovation in materials science can contribute to reducing the construction industry’s carbon footprint, paving the way for a more sustainable future.