Research: Corn Might Improve Concrete Durability
In a bid to provide a sustainable building material for aging infrastructure in the U.S., researchers at the University of Nebraska at Kearney recently investigated whether ash produced by burning corncobs and corn stover could be used to strengthen concrete.
Currently, materials such as fly ash and silica fume are used to strengthen the building material, but fly ash will become harder to obtain as bans on coal-generated electricity continue to widen.
The research, spearheaded by Mahmoud Shakouri, an assistant professor of construction management, sought to determine whether ash created by burning corncobs and corn stover could be used in place of materials like fly ash.
In one study, the researchers looked at using corncob ash to decrease the permeability of concrete.
“Given that corncob is an affordable and sustainable product in Nebraska, the application of this agricultural waste in the concrete industry contributes to a more durable and sustainable society and infrastructure,” Shakouri said. “This project can also offer opportunities to create jobs and benefit the economy of the state.”
In a second study, corn stover ash was used as a replacement for "coal combustion byproducts in cement." By mixing ash with cement, the team believes the new concrete mixture would help reduce environmental impact by cutting back on the amount of energy needed to produce cement.
Shakouri received $205,000 from the Nebraska Research Initiative to purchase equipment for material characterization and corrosion assessments. The team also has “a high-temperature cyclonic furnace to burn the corncobs and stover and a compression testing machine to measure the strength of concrete,” according to the university.
According to Shakouri, the idea of using ash in cement is not new; the Roman empire used ash in its concrete, and those structures are still standing today.
"What happened was after civilization, there was a lot of byproduct from the industry, and they started to move away from these natural things to things that are cheaper and available, so this is not a new concept,” Shakouri said.
The research is slated to conclude in spring of 2019. Funding for the corncob project is provided by Nebraska’s Established Program to Stimulate Competitive Research, which is part of a National Science Foundation endeavor focused on STEM research. Stover work is funded by a UNK Collaborative Research Grant.