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Innovative 3D Concrete Printing Method Aims to Capture Carbon and Reduce Emissions
Researchers at Nanyang Technological University, Singapore (NTU Singapore) have unveiled an innovative method for 3D concrete printing that integrates carbon capture technology, offering a prospective direction for minimizing the environmental footprint of the construction sector.
This cutting-edge approach, published in the journal Carbon Capture Science & Technology, seeks to address the significant carbon emissions associated with traditional cement production, which is responsible for an estimated 1.6 billion metric tonnes of CO2 annually—equating to approximately eight percent of global emissions. The new technique not only aims to decrease the material requirements and streamline construction timelines but also aims to lower labor costs.
The process involves injecting steam and CO2—captured as by-products from various industrial activities—into the concrete mix during the printing process. This technique allows for the direct integration and long-term storage of CO2 within the concrete itself.
Initial findings indicate that incorporating CO2 and steam not only enhances the mechanical characteristics of the printed concrete but also surpasses the performance of traditional 3D printed concrete in terms of strength and durability.
Professor Tan Ming Jen, the principal investigator of the study from NTU’s School of Mechanical and Aerospace Engineering (MAE) and the Singapore Centre for 3D Printing (SC3DP), stated, “The construction industry is a significant contributor to global greenhouse gas emissions. Our advanced 3D concrete printing system presents an eco-friendly alternative that enhances concrete properties while mitigating the sector’s environmental impact. This method showcases the potential use of CO2 from power plants and other industrial sources in construction applications, contributing to sustainable practices by reabsorbing carbon traditionally emitted during cement production.”
The team is optimistic that their development could be a vital step toward meeting global sustainability targets and decreasing dependency on traditional, energy-intensive concrete production methods.
Technical Advancements in 3D Printing
To create this advanced 3D printing system, the research group connected a 3D printer to carbon dioxide pumps and a steam injection nozzle. This integrated system introduces steam and CO2 into the concrete mixture throughout the printing phase. The reaction between these components leads to the solidification of CO2 within the material, effectively carbon sequestering it while the steam enhances carbon absorption within the structure.
Laboratory tests revealed that the printed concrete exhibited a remarkable 50 percent increase in printability, allowing for more efficient shaping and construction. The concrete demonstrated enhanced strength and endurance, with improvements of up to 36.8 percent in compressive strength (the ability to withstand weight) and up to 45.3 percent in flexural strength (the capacity to bend without breaking) compared to standard 3D printed concrete.
In addition to these performance boosts, the new method is greener, with the ability to capture and sequester 38 percent more carbon dioxide than traditional 3D printing methods.
Contributions to Sustainable Construction
Lim Sean Gip, a PhD candidate and the first author of the study, emphasized the urgency of addressing climate change, stating, “As the global efforts to combat climate change intensify, we see our technology as a pivotal stride towards a more sustainable construction sector.”
Dr. Daniel Tay, a co-author and Research Fellow at NTU’s MAE, added, “Our innovative system illustrates how integrating carbon capture into 3D concrete printing can lead to buildings that are both stronger and more environmentally friendly, marking an advancement in construction technology.”
A patent application for this groundbreaking technology has been filed in the United States, with plans for future research aimed at optimizing the printing process for greater efficiency and exploring the use of waste gases instead of pure carbon dioxide.
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