Researchers at Princeton University’s Department of Civil and Environmental Engineering have created a new type of concrete that’s 560% stronger, simply by using less materials.
The new concrete, which is full of hollowed-out shapes, was inspired by the cortical bone structure of the human femur.
“To date, a few studies have only explored the design of composites inspired by cortical bone architecture…to improve energy absorption (toughness), fracture toughness, and flexural strength,” wrote Shashank Gupta and Reza Moini, the authors of the study.
Cortical bone (also known as compact bone) is dense, strong bone tissue that makes up the majority of the human skeleton.
It is made up of tiny, tube-like structures called osteons, which are surrounded by softer material. Ironically, the area between these tubes, which are weaker, are scientifically referred to as “cement lines.”
When a crack happens in the human bone — like the femur, which inspired this study — the cracks follow the cement lines and stop at the osteons, preventing the whole bone from breaking.
Inspired by how our bones handle stress, Gupta and Moini replicated the formation of cortical bone by making concrete through a “hybrid 3D-printing/casting process” and engineering “tubular cement-based materials” that resembled the honeycomb-like structure of the femur.
By repeating the study and testing different sizes of tube structures, they toughened the resiliency of the material.
“The bone-inspired composites exhibited limited improvement of up to 26% in fracture toughness and 30% in flexural strength compared to conventionally laminated counterparts,” wrote the researchers.
“Conventional cement-based materials exhibit brittle failure under fracture due to limited toughening mechanisms such as uncracked ligament bridging and microcracking,” they concluded.
Gupta and Moini’s new study shows that when it comes to environmental design, “more” doesn’t always mean “better.”
Unlike traditional concrete that often requires additional fibers or plastics for strength, this new variant relies solely on its geometric design. This simple new method not only makes the material more environmentally friendly, but it also reduces overall production costs.
Although the production of this concrete is still in its infancy at Princeton University’s labs, Gupta and Moini’s bio-inspired design holds a great deal of potential for the future of infrastructure.
In their conclusion, Gupta and Moini invited other scientists to revisit their analysis “from a statistical mechanics approach” to discover and develop “new mechanisms, principles, and insights beyond bio-inspired schemes.”
Image via RobbieWi / Pixabay (Public Domain)