Bones drive better concrete
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Inspired by human bones, Princeton engineers have toughened concrete to resist catastrophic failure.
Researchers have created a cement-based material that is 5.6 times more damage-resistant than standard options.
The innovative design could significantly enhance the durability of concrete used in construction and civil infrastructure.
The material’s resilience is attributed to its internal architecture, modelled on human cortical bone, which is the tough outer shell of bones like the femur.
Cortical bone contains elliptical tubular structures known as osteons, embedded weakly in a matrix.
This arrangement deflects cracks and prevents abrupt failures, which significantly increases the material's resistance to damage.
“We use theoretical principles of fracture mechanics and statistical mechanics to improve materials’ fundamental properties by design,” said Reza Moini, an assistant professor of civil and environmental engineering.
The new cement incorporates cylindrical and elliptical tubes within its structure, mimicking the bone’s composition.
When cracks form, they are directed around the tubes, which increases the amount of energy required to propagate the crack.
This leads to a toughening mechanism that prevents sudden structural failures.
“What makes this stepwise mechanism unique is that each crack extension is controlled, preventing sudden, catastrophic failure,” said researcher Shashank Gupta, a third-year PhD candidate.
The breakthrough lies in the geometric design of the material, which enhances crack resistance without the need for added materials such as fibres or plastics.
By precisely controlling the shape, size, and orientation of the tubes, the material achieves significant toughness without sacrificing strength.
Beyond improving fracture resistance, the team developed a new method to quantify the degree of disorder within the material’s architecture.
By using statistical mechanics, they can design materials with tailored degrees of disorder, which can be further enhanced through additive manufacturing techniques.
The experts say advanced manufacturing methods can help scale this design for civil infrastructure projects.
“We've only begun to explore the possibilities,” Gupta said.
Future research could involve modifying tube size, shape, and other variables to optimise the material for different applications.
More details are accessible here.
