Breakthrough in materials

Engineers have created a new cement composite 17 times more crack-resistant than standard cement and 19 times more able to stretch without breaking.

Inspired by oysters and abalone shell material, the Princeton University engineers created concrete beams with alternating layers of tabulated cement paste and thin polymer.

Their findings published in the journal Advanced Functional Materials, revealed significant increased crack resistance and the ability to deform without completely breaking.

The team looked at the microscopic level of mother of pearl (nacre) and found it consists of hexagonal tablets of the hard mineral aragonite glued together by a soft biopolymer.

Aragonite tablets contribute significantly to nacre’s strength, according to the researchers, while the biopolymer adds flexibility and crack resistance.

“The toughening mechanism involves the aragonite tablets sliding under stress, which, along with other mechanisms, allows the nacre to dissipate energy,” the team stated.

“This sliding action, combined with the crack deflection and biopolymer deformation, enables nacre to endure substantial mechanical stress while maintaining its structural integrity, making it both strong and resilient.”

The researchers created multi-layered small beams by alternating cement paste sheets with thin layers of polymer. These beams were then subjected to a notched three-point bending test, where each beam was tested under flexure to evaluate crack resistance.

About the author

Desi Corbett

Desi is the Editor of Concrete in Australia and at the helm of our magazine for 8 years. She was behind the Institute's weekly news bulletins from 2016-2021 and is now writing our focused news items. Desi has been an engineering news and features journalist/editor across all disciplines since 2013 - part of a 30-year career writing for a wide range of industries.