During An Earthquake, "Smart Concrete" Could Fare Better Than Conventional Materials

BUFFALO, N.Y. -- A new formulation of concrete that is stronger than conventional concrete and has the unique ability to tell humans about tiny cracks that occur within it might be a better alternative to conventional materials for buildings and bridges, particularly during an earthquake, according to a University at Buffalo engineer.

"Smart concrete" has the ability to "sense" tiny structural flaws before they become significant, which could be of use in monitoring the internal condition of structures before and following an earthquake.

Composed of tiny carbon fibers mixed into concrete with a conventional concrete mixer, the new material is tougher and stronger flexurally than conventional concrete.

"It takes greater force for smart concrete to bend, and it absorbs more energy before fracture," said Deborah D.L. Chung, Ph.D., UB Niagara Mohawk chair of materials research and developer of the new material.

Therefore, she said, the new formulation should be able to withstand stronger forces than conventional concrete.

In addition, the presence of the carbon fibers also controls the cracking so that the cracks do not propagate catastrophically, as in the case of conventional concrete, Chung said.

"The controlled cracking can be detected by electrical probing as the concrete's electrical resistance will increase in the presence of a flaw," said Chung.

"That smart concrete is itself a sensor is in sharp contrast to conventional technologies in which optical fibers or other sensors need to be embedded in the concrete," she said.

Chung presented the research on smart concrete earlier this month at the International Workshop on Civil Infrastructure Systems in Taipei, Taiwan. A paper on it was also published last year in an issue of Smart Materials and Structures.