University of Pennsylvania Develops Carbon-Absorbing Bridge
A research team at the University of Pennsylvania has unveiled an innovative pedestrian bridge that not only showcases advanced engineering but also addresses environmental concerns. This bridge, known as Diamanti, utilizes a unique 3D printing method and a specially formulated concrete mixture that absorbs significantly more carbon dioxide than traditional materials.
Concrete is the most widely used manmade material globally, but it contributes to approximately 8% of total greenhouse gas emissions. The cement industry has been striving for sustainability, reducing its carbon emissions by 25% per metric ton since 1990. Despite this progress, emissions have risen due to increasing demand, as reported by the International Energy Agency (IEA).
Diamanti aims to mitigate this issue by employing a sustainable concrete mixture that absorbs 142% more carbon dioxide than conventional concrete. The project draws inspiration from nature, particularly from the porous structures found in bones, as explained by Masoud Akbarzadeh, an associate professor of architecture at the university. “Through millions of years of evolution, nature has learned that you don’t need material everywhere,” he noted. By mimicking these natural structures, the bridge not only reduces material usage by 60% but also enhances the concrete’s carbon absorption capabilities.
Innovative Materials and Design
The concrete mixture for Diamanti incorporates diatomaceous earth, a naturally porous material derived from fossilized algae. This innovative addition creates channels within the concrete, allowing carbon dioxide to penetrate deeper and enhancing the material’s overall absorption ability. While the global production of diatomaceous earth was approximately 2.6 million tons in 2023, experts like Du Hongjian from the National University of Singapore emphasize the need to consider supply chain implications for widespread adoption.
Diamanti’s design is modular, with each block printed using a robotic arm and connected via tensile cables. This construction method not only reduces material and energy use by 25% but also cuts the requirement for steel by 80%, further minimizing emissions associated with construction. Akbarzadeh remarked that the initial five-meter prototype exceeded expectations during load testing, solidifying the project’s potential for real-world applications.
Looking Ahead: Full-Scale Prototype in France
Initiated in 2022 and developed in collaboration with Swiss-based Sika Group, the Diamanti project is preparing to construct its first full-scale prototype in France. While the original plan included a site in Venice, regulatory changes prompted the team to seek alternative locations. Currently, potential sites include iconic waterways in Paris, where digital renderings have visualized the bridge over the River Seine.
Akbarzadeh expressed enthusiasm for testing Diamanti in practical settings, stating, “We hope this can create a whole new world of possibilities for concrete.” Beyond bridges, the team is also exploring applications in prefabricated floor systems, emphasizing that while this technology is not a one-size-fits-all solution, it represents a significant advancement in sustainable construction practices.
The findings from the Diamanti project were published in Wiley’s Advanced Functional Materials journal, showcasing the potential of this innovative approach to concrete design. As the construction sector continues to grapple with environmental challenges, projects like Diamanti may pave the way for a more sustainable future in infrastructure.
