DECATUR — A few miles of city road are part of a pilot project to test the long-term performance of a vegetable oil-based additive for asphalt developed by Archer Daniels Midland Co.
"It's locally made and we've gotten good reports on how it's worked ... we wanted to give it a whirl," said Decatur Public Works Director Matt Newell.
The product has no name, but the agribusiness giant worked with Midlothian-based liquid asphalt maker Seneca Petroleum Co. in 2015 to manufacture an asphalt mix that ADM says is superior to what crews have been using to pave roads and parking lots for years.
"We found the product to be more durable and superior to products that used petroleum-based additives alone and believe it has the potential for broader applications," said Dave Sands, ADM's general manager of specialty oils.
Crews alternated the use of the ADM-developed liquid asphalt and traditional petroleum-based asphalt on paving work at East Lawrence Street between south 16th and 19th streets this summer. City engineers will also be able to see a side-by-side comparison on paving work scheduled for later this summer on East Fitzgerald Road.
Decatur-based Dunn Co., a paving contractor that has done many public projects in the area over the years, has played a strategic role in putting the new type of asphalt to use. In 2016, Dunn Co. paved the parking lot of South Shores Park under contract with the Decatur Park District.
"We've had a great longstanding relationship performing work for ADM and they approached us for being their collaborator to pilot this material in the field," said David Tyrolt, Dunn Co.'s president and CEO.
ADM officials hope pilot work like the city's road paving projects will lead to its use across the state for larger work overseen by the Illinois Department of Transportation. Current IDOT rules do not allow road construction with any non-petroleum based materials.
On Wednesday, Dunn Co. crews paved a stretch of Airport Road as part of a contract with the city. But unlike the work on East Fitzgerald and East Lawrence Streets, the Airport Road work is funded by IDOT rather than the local motor fuel tax.
"The state is now evaluating the performance of vegetable oil and other non-petroleum additives on a limited number of local and state paving projects and may potentially expand these innovations in future years," Sands said.
Dunn Co. has been used the material in several projects since 2015, and Tyrolt says the early results have been promising.
"One thing that shows up relatively early in a pavement's life is oxidation," he said, referring to the chemical process that can make asphalt more brittle and fall apart over time. "And just anecdotally examining the pavements after they've been down for a handful of years in some cases, we're seeing less oxidation."
Other states, like Indiana, have already started to permit the use of ADM's asphalt additive, Tyrolt said. If IDOT's evaluations lead to a green light for the vegetable additive, roads across Illinois could one day have ADM-derived chemistry baked into them.
"It's rewarding to see a project like this come to life in your own backyard," Sands said.