The first-ever bioinspired 3D-printed cement paste element shows promise for making infrastructure more resilient to mechanical loads, like those that occur during natural disasters. Source: Purdue University Concrete 3D Printing Team/Mohamadreza Moini

Researchers from Purdue University have created a 3D-printed cement paste that can be used to create concrete structures. It is designed to get stronger when put under pressure, making it possible to create structures that are more resilient and that get stronger during natural disasters. Engineers use 3D-printed material so that they can control the design of their structure.

"Nature has to deal with weaknesses to survive, so we are using the 'built-in' weaknesses of cement-based materials to increase their toughness," said Jan Olek, a professor in Purdue's Lyles School of Civil Engineering.

The new cement paste was inspired by arthropods' exoskeletal structure. Specifically, the researchers looked at the mantis shrimp’s dactyl club and observed how it manages to stay intact when the shrimp uses it.

"The exoskeletons of arthropods have crack propagation and toughening mechanisms that we can reproduce in 3D-printed cement paste," said Pablo Zavattieri, Purdue professor of civil engineering.

"3D printing has removed the need for creating a mold for each type of design, so that we can achieve these unique properties of cement-based materials that were not possible before," said Jeffrey Youngblood, Purdue professor of materials engineering.

The team used micro-CT scans to understand the behavior of the 3D-printed cement paste materials, and to study and improve the weak areas.

"3D printing cement-based materials provides control over their structure, which can lead to the creation of more damage and flaw-tolerant structural elements like beams or columns," said Mohamadreza "Reza" Moini, a Purdue Ph.D. candidate of civil engineering.

A few 3D-printing techniques were used during the process of creating the new cement, including honeycomb, compliant and Bioligand. These different architectures allowed for new behaviors to emerge.

The paper on this technology was published in the journal Advanced Materials.