Researchers at the University of New Mexico’s Gerald May Department of Civil, Construction, and Environmental Engineering have developed an innovative material that could transform the future of construction and infrastructure maintenance. The material, a self-reinforced ultra-ductile cementitious substance, was designed specifically for 3D printing concrete structures, offering enhanced resilience and reduced reliance on traditional reinforcement methods. This breakthrough is poised to make concrete structures stronger, more flexible, and more durable—ultimately improving the lifespan and cost-effectiveness of public infrastructure.
Traditional construction processes often involve heavy machinery, steel beams, and manual labor, which can be expensive and dangerous. Additionally, maintaining concrete structures is an ongoing challenge due to the material’s brittleness and tendency to crack under tension. Even reinforced concrete, which is commonly used for buildings, bridges, and sidewalks, requires continuous repairs.
Maryam Hojati, Assistant Professor of Civil, Construction, and Environmental Engineering, and her team are addressing these pressing issues. Concrete is known for being strong under compression, but it fails under tension, making it vulnerable during events such as earthquakes or high winds. By developing a material capable of handling both tension and compression, the team hopes to create longer-lasting, more resilient infrastructure.
While 3D printing has already made its mark in the construction industry, most processes still require external reinforcements like steel beams or rebar. This limits the full automation potential of 3D printing, where the material must be strong enough to hold its shape without additional support.
Muhammad Saeed Zafar, who completed his Ph.D. in 2024 under Hojati’s guidance, has developed a solution that could address this issue. Zafar and his colleagues created a self-reinforced, ultra-ductile cementitious material that can be 3D printed without needing external reinforcements like steel bars. Their innovative substance, which was patented in August 2024 by UNM Rainforest Innovations, is a significant step forward in the quest for fully automated concrete 3D printing.
“If we can design an ultra-ductile material that doesn’t rely on conventional steel reinforcement, we solve the incompatibility between traditional reinforcement and the 3D printing process,” Zafar explained.
The material, which includes fiber additives to enhance its flexibility and tensile strength, must balance viscosity and fiber content to allow smooth printing without collapsing. If too little fiber is used, the printed shape could buckle under its own weight. Too much fiber, and the material may become too thick, clogging the printer nozzle. To fine-tune the material, the team experimented with various combinations of fibers like polyvinyl alcohol, fly ash, silica fume, and ultra-high molecular weight polyethylene.
Their efforts paid off with a versatile material capable of achieving up to 11.9% higher strain capacity compared to conventional concrete. According to Hojati, “The incorporation of large quantities of short polymeric fibers helps hold the concrete together under bending or tension loads, reducing the need for external reinforcement.”
The research was funded through grants from the Transportation Consortium of South-Central States (Tran-SET) and the Region Six University Transportation Center, and is expected to significantly impact the construction industry. With this new material, 3D printed concrete structures could become more resilient to natural disasters, require less maintenance, and be produced with greater automation.
Beyond Earth, this technology could even play a role in space exploration. The challenges of building structures on other planets, where heavy materials and large construction teams are impractical, have prompted space agencies like NASA to explore the use of 3D printing. Robots equipped with 3D printers could one day be used to construct habitats on the Moon or Mars, using locally sourced materials.
On Earth, the technology has the potential to revolutionize public infrastructure. With more resilient and cost-effective 3D printed concrete materials, cities could reduce repair costs and extend the lifespan of roads, bridges, and buildings.
“This was very successful research,” said Hojati. “This material not only has 3D printing properties but also high structural viability, making it a strong candidate for use in the construction industry.”
The team’s work represents a significant step toward the future of automated, sustainable construction and infrastructure that could help address long-standing challenges in the industry.
By Impact Lab
