There has been a lot of talk in the U.S. about infrastructure recently. This brings attention to construction materials and the feasibility of using smart materials, which incorporate more carbon. But higher carbon levels can decrease the performance and durability.
A professor at Northwestern University in Illinois developed a smarter concrete that is more durable and functional. She enhanced ordinary concrete with the nanomaterial graphene — a super-strong material composed of a single layer of carbon atoms.
“The role of nanoparticles in this application has not been understood before now, so this is a major breakthrough,” engineering professor Ange-Therese Akono said in a news release.
The nanomaterial is created through a high-tech, four-step process that uses deionized water, ultrasonic energy, and digital equipment like an electron microscope.
Concrete typically undergoes “fracture testing” to determine its strength. The process uses light beams, but it takes a lot of time and materials. Akono instead “scratch tested” her nanomaterials by electronically probing them to determine their strength and likelihood to fracture.
“My method is applied directly at the micrometer and nanometer scales, which saves a considerable amount of time,” Akono said. “And then based on this, we can understand how materials behave, how they crack, and ultimately predict their resistance to fracture.”
Akono determined that incorporating even a small amount of graphene enhances the concrete’s fracture resistance as well as its resistance to water penetration. This type of nanomaterial-enhanced concrete is also lighter.
Increasing the durability reduces the amount of concrete needed for each structure, and therefore lowers concrete’s carbon footprint, according to the research. This research has implications not just for greener construction, but also for optimally incorporating sensors into concrete for infrastructure monitoring.
Akono intends to further advance this research by increasing the amount of nanomaterials and exploring the use of construction waste as a concrete material.