Scientists Transform CO2 Into Super-Strong 3D Printed Concrete

Scientists have developed a new 3D concrete printing method that captures carbon, enhancing the material’s strength and sustainability.

This innovation significantly reduces the construction sector’s carbon emissions by incorporating CO2 directly into the concrete, promising a greener future for construction technologies.

Innovative 3D Concrete Printing

Researchers at Nanyang Technological University, Singapore (NTU Singapore) have created a 3D concrete printing method that captures carbon, offering a new way to reduce the construction industry’s environmental impact.

This method targets cement’s significant carbon footprint, which accounts for around eight percent of global CO2 emissions.

Detailed in the journal Carbon Capture Science & Technology, the technique focuses on lowering emissions by reducing material usage, speeding up construction, and cutting labor needs.

Enhancing Concrete with Carbon Capture

The process works by injecting steam and CO2 — captured as by-products from industrial processes — into the concrete mix during printing. This innovative method allows the concrete to trap and store CO2 within its structure, improving both its sustainability and strength.

Tests showed that this approach not only sequesters carbon but also strengthens the concrete. The printed material demonstrated greater mechanical strength compared to conventional 3D-printed concrete.

Members of the research team from the NTU School of Mechanical and Aerospace Engineering (MAE), and NTU’s Singapore Centre for 3D Printing (SC3DP), include (L-R) Dr. Suvash Paul, Senior Research Fellow; Dr. Daniel Tay, Research Fellow; Lim Sean Gip, PhD candidate; Prof Tan Ming Jen, Principal Investigator; Dr. Lee Junghyun, Research Fellow. Credit: NTU Singapore

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Advancements in Concrete Printing Technology

Principal investigator of the study, Professor Tan Ming Jen, from NTU School of Mechanical and Aerospace Engineering (MAE) and NTU’s Singapore Centre for 3D Printing (SC3DP), stated, “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.”

The method demonstrates how CO2 produced by industries can be repurposed for sustainable construction.

The research team believes their innovation represents a promising contribution toward achieving global sustainable development goals and reducing the industry’s reliance on energy-intensive processes.

Advancements in Printing and Material Strength

To develop their 3D concrete printing system, the research team connected the 3D printer to CO2 pumps and a jet that sprays steam. This setup allows CO2 to react with the components in the concrete mix, turning into a solid form that stays locked within the material.

The steam improves CO2 absorption into the printed structure, enhancing its properties and contributing to more sustainable construction processes.

Lab Results Demonstrate Significant Improvements

In lab tests, the printed concrete structure showed a 50 percent improvement in printability, allowing it to be shaped and printed more efficiently. The material was up to 36.8 percent stronger in compression and 45.3 percent stronger in bending compared to traditional 3D-printed concrete.

The method also absorbed and trapped 38 percent more carbon dioxide than traditional 3D printing processes, further emphasizing its environmental benefits.

A Greener, Stronger Future for Construction

First author Lim Sean Gip, PhD candidate from NTU School of MAE, remarked, “We are at a critical time where the world is accelerating efforts to meet climate change targets. We believe our technology could contribute to making the construction industry more sustainable.”

Co-author Dr. Daniel Tay, Research Fellow from NTU School of MAE, 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.”

A US patent application for the innovation has been filed jointly by NTU and collaborators. Future research will aim to optimize the 3D printing process for greater efficiency and explore the use of waste gases instead of pure carbon dioxide.

Reference: “Carbon capture and sequestration with in-situ CO2 and steam integrated 3D concrete printing” by Sean Gip Lim, Yi Wei Daniel Tay, Suvash Chandra Paul, Junghyun Lee, Issam T. Amr, Bandar A. Fadhel, Aqil Jamal, Ahmad O. Al-Khowaiter, and Ming Jen Tan, 26 September 2024, Carbon Capture Science & Technology. DOI: 10.1016/j.ccst.2024.100306