Quick summary:
• Scientists at NTU Singapore developed a 3D printing method that captures and stores carbon dioxide in concrete, reducing its environmental impact.
• The process integrates CO2 and steam, sourced from industrial by-products, into the concrete mix during printing, both sequestering emissions and improving material properties.
• The modified concrete is 36.8 percent stronger, 45.3 percent more flexible, and 50 percent more efficient to print compared to standard 3D-printed concrete.
• The new material captures 38 percent more carbon, helping address cement production’s role as a major contributor to global CO2 emissions (8 percent globally).
• Cement manufacturing produced 1.6 billion metric tonnes of CO2 in 2022, with projections to reach 3.8 billion metric tonnes annually without intervention.
• This innovation aligns with global efforts to create sustainable building materials, complementing other advancements like using recycled glass and plant-based additives in construction.
• Researchers filed a U.S. patent for the technology, aiming to scale it for industrial use and promote its adoption in the construction sector.
A team of scientists from Nanyang Technological University (NTU), Singapore, has developed a groundbreaking method to 3D print concrete that captures and stores carbon dioxide, offering a potential revolution in sustainable construction practices. The technique not only reduces the environmental impact of concrete but also strengthens the material, making it a viable alternative for modern construction.
The process involves integrating carbon dioxide (CO2) and steam into the concrete mix during the 3D printing process. Both CO2 and steam are sourced as by-products from industrial processes, making the approach a novel way to repurpose emissions while simultaneously reducing the carbon footprint of construction materials.
To execute this method, researchers connected a 3D printer to steam jets and CO2 pumps, injecting these elements directly into the cement as it was mixed and printed into structures. By trapping CO2 in the concrete during its formation, the process achieves a twofold benefit: it sequesters carbon that would otherwise be released into the atmosphere and enhances the structural properties of the material.
“The building and construction sector causes a significant portion of global greenhouse gas emissions. Our newly developed 3D concrete printing system offers a carbon-reducing alternative by not only improving the mechanical properties of concrete but also contributing to reducing the sector’s environmental impact,” said Tan Ming Jen, principal investigator of the study and professor at NTU’s School of Mechanical and Aerospace Engineering.
In addition to its environmental benefits, the modified concrete boasts significantly enhanced performance compared to standard 3D-printed concrete. Key findings include:
• 36.8 percent greater weight-bearing capacity than typical 3D-printed concrete.
• 45.3 percent increased flexibility, making it more resistant to stress and cracking.
• 50 percent improvement in printability, enabling faster and more accurate 3D printing.
• 38 percent higher carbon capture efficiency, reducing the carbon footprint of the material further.
The enhanced durability and sustainability of this new concrete make it ideal for use in both small-scale projects and large-scale construction, where durability and environmental impact are key considerations.
The cement industry is one of the largest contributors to greenhouse gas emissions, accounting for approximately 8 percent of global CO2 emissions, according to the World Economic Forum. In 2022 alone, emissions from cement manufacturing reached 1.6 billion metric tonnes, with projections suggesting that figure could rise to 3.8 billion metric tonnes per year under a business-as-usual scenario.
By addressing the dual issues of high emissions and material inefficiency, NTU’s innovation could transform a sector that has historically been resistant to environmental reforms. “It demonstrates the possibility of using CO2 produced by power plants or other industries for 3D concrete printing. Since traditional cement emits a lot of carbon, our method offers a way to plough back CO2 through 3D concrete printing,” Tan explained.
The NTU team’s work is part of a broader global push to make construction more sustainable. Recent advancements in 3D printing have focused on reducing waste, minimizing material usage, and incorporating alternative materials. For instance:
• Researchers at MIT have explored using recycled glass in 3D-printed concrete.
• Scientists at the University of Virginia are developing methods to incorporate plant-based cellulose nanofibrils into concrete.
While these innovations hold promise, NTU’s technology stands out for combining material performance improvements with direct carbon sequestration.
“Our proposed system shows how capturing carbon dioxide and using it in 3D concrete printing could lead to stronger, more eco-friendly buildings, advancing construction technology,” said Daniel Tay, co-author of the study and a research fellow at NTU.
The researchers have filed a U.S. patent application for their carbon-capturing 3D printing method, signaling their intention to commercialize the technology. The next steps involve scaling the process for broader industrial applications and encouraging its adoption within the construction sector.
By partnering with companies that capture CO2 emissions and aligning with global sustainability goals, NTU hopes to position this technology as a key player in reducing the environmental impact of construction.
This breakthrough highlights the potential of 3D printing to revolutionize construction practices. It demonstrates how innovations in material science can address pressing environmental challenges while improving the efficiency and durability of building materials.
As the construction industry continues to grapple with its outsized role in global emissions, NTU’s method offers a compelling blueprint for sustainable progress. “This is a significant step forward in leveraging technology to reduce emissions while meeting the growing demand for resilient infrastructure,” Tan concluded.
To learn more about the 3D concrete printing method, watch NTU’s video.
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