Researchers at Iowa State University are hoping to build better roads in the state with a co-product of ethanol. Halil Ceylan is an assistant professor of civil, construction, and environmental engineering at ISU. He says most Iowa soils are weak in nature and must be combined with chemicals to add strength for a solid roadbed.
Ceylan is hoping to improve the strength of the soil under Iowa roads with lignin, a co-product of producing ethanol from plant fibers. He describes lignin as the "glue" that holds the fibers together. "We plan to mix different amounts of lignin with different Iowa soils and find out what will be the optimum amount of lignin we need to stabilize and improve the strength and overall engineering properties of the road bed soils," Ceylan says of his team’s research.
The ethanol boom in Iowa is also bringing more truck traffic, which makes Ceylan’s research even more important. He says county engineers are concerned about the increased traffic, "and with this (research), at least we can give something back them so they can use this material for soil stabilization." Lignin may provide another benefit for rural roads. Ceylan says it can cut down on dust pollution.
"You can spray lignin on gravel," Ceylan explains, "and it will form a firm crust on top of the road structure, and that will significantly reduce the dust emissions into the atmosphere." The research at ISU is being supported in part by a grant of nearly $94,000 from the Grow Iowa Values Fund.
The project is also receiving financial support from the Iowa Highway Research Board, Grain Processing Corp. of Muscatine, and Iowa State’s Office of Biorenewables Programs.