Can layers inspired by crustacean shells help cement composites absorb more energy when they bend?

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This laboratory study applied a biological structure inspired by crustacean shell shapes to improve the energy absorption capacity of fiber-reinforced cement composites. Researchers made layered bending specimens using cement composites and three types of precast panels with different surface shapes. They used flexural testing to evaluate bending behavior and energy absorption capacity.

Before the flexural tests, uniaxial tensile testing evaluated the tensile behavior of the mix used. Its average tensile strength was 5.31 MPa, and its average tensile strain was 3.89%.

In the flexural tests, the first-crack flexural strength was 3.9 MPa for the Plain specimen and 3.6–4.1 MPa for the layered specimens, indicating similar performance. Maximum flexural strengths across all specimens were also similar, ranging from 8.5 to 9.2 MPa, with a maximum difference of 8%, described as minor.

The layered approach improved deformation capacity during bending and increased energy absorption capacity to as much as 1.78 times that of the Plain specimen. Energy absorption increased particularly in Type-R specimens with uneven interfaces and Type-W specimens with wavy interfaces.

The researchers attributed these results to the curved panel interfaces improving adhesion at the joining surfaces while allowing appropriate delamination, sliding, and interlocking. They interpreted these processes as suppressing reflective cracking while allowing numerous microcracks to form.