3D Concrete Printing Method Captures Carbon to Reduce Environmental Impact
3D Concrete Printing Method Captures Carbon to Reduce Environmental Impact
Researchers at Nanyang Technological University (NTU Singapore) have developed an innovative 3D concrete printing technique that captures carbon, offering a new approach to lessen the environmental footprint of the construction industry. Published in Carbon Capture Science & Technology, this method aims to decrease the carbon footprint of cement, a material responsible for about 1.6 billion metric tonnes of CO2 emissions annually—roughly eight percent of global CO2 emissions.
The 3D concrete printing process involves injecting steam and CO2, captured as by-products from industrial processes, into the concrete mix. This method integrates the CO2 into the concrete structure, storing it and reducing emissions. Research results show that this CO2 and steam injection technique not only lowers material usage but also improves the mechanical properties of the concrete, resulting in increased strength compared to traditional 3D printed concrete.
Professor Tan Ming Jen, the study’s principal investigator and a faculty member at NTU's School of Mechanical and Aerospace Engineering (MAE) and Singapore Centre for 3D Printing (SC3DP), emphasized, "The building sector contributes significantly to global greenhouse gas emissions. Our new 3D concrete printing system offers a carbon-reducing alternative by improving concrete properties and helping reduce the sector’s environmental impact. It also demonstrates the feasibility of using CO2 from power plants or other industries in 3D concrete printing."
The research team views their innovation as a key step toward achieving global sustainability goals and reducing the industry's dependence on energy-intensive processes like reinforced concrete construction. This advancement builds on previous 3D printing research by Professor Tan and his team at NTU, along with international collaborators.
Improved Properties and Carbon Capture
The new 3D concrete printing system integrates CO2 pumps and a steam jet to inject both elements into the concrete mixture during the printing process. The CO2 chemically reacts with the components of the concrete, turning into a solid and being sequestered within the material. Meanwhile, the steam aids in absorbing CO2 into the structure, improving its properties.
Lab tests showed that this method enhanced the printability of the concrete by 50%, making it more efficient to shape and print. The concrete also demonstrated improved strength and durability, being 36.8% stronger in compression (resistance to weight) and 45.3% stronger in bending (flexibility before breaking) compared to conventional 3D printed concrete. Additionally, this method trapped and stored 38% more CO2 than traditional 3D printing techniques.
First author, Lim Sean Gip, a PhD candidate at NTU, highlighted, "As the world pushes to meet climate change targets, we believe our technology can help make the construction industry more sustainable." Co-author Dr. Daniel Tay, a research fellow at NTU, added, "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."