A soybean-based sealant that's shown positive results compared to other sealants was the topic March 10 for the latest AURI Wednesday webinar.

The Agricultural Utilization Research Institute has worked with a variety of partners, including the Minnesota Soybean Research and Promotion Council and the city of Hutchinson, to test RePlay, a USDA-biobased, certified road preservation product produced by BioSpan Technologies.

RePlay uses the oil from about 100 bushels of soybeans per lane mile, said Jimmy Gosse, a microbiologist at AURI. Last year marked the fifth year AURI that has worked on bio-based asphalt preservation.

“It’s been a long journey, and today’s really going to be a road trip,” Gosse said. “AURI, from the beginning, understood the complexity of the tasks we were undertaking, and has gone on to identify, work with and build on the research of many industry-leading groups that have been active in this space for years.”

How does RePlay differ from traditional sealants? Chip sealing is the traditional method of sealing a road to extend its life span. In this process, hot tack is sprayed onto a blacktop road, and then aggregate is applied. The aggregate may chip windshields and end up in car garages. The road is restriped following the application. RePlay, by contrast, cures in 30 minutes. There is no need for aggregate or restriping after application. It penetrates three quarters of an inch to an inch and a quarter deep into blacktop. It is 88% bio-based. The results of a statistical analysis using data from Hutchinson, Minn., show that RePlay has a deterioration rate that is four times lower than an untreated surface  “Soybean oil is paving the future of road preservation, all while providing a financial benefit to cities and taxpayers here in Minnesota,” said Mike Youngerberg, MSRPC director of product development. “This study confirmed the true benefit and increased longevity RePlay provides to treated surfaces."

The study was conducted by SRF Consulting Group. In its life-cycle cost analysis, SRF found that RePlay treatments resulted in lower costs than the do-nothing scenario on low-volume roads.

“Soy bio-based pavement preservation products used in the Hutchinson case study are clearly showing benefits in preserving the integrity and life of the roads,” said Harold Stanislawski, AURI’s project development director. “This ultimately saves taxpayer funds and allows dollars to be stretched farther in improving more roads and trails.”

How long does RePlay extend the life of pavement? A data scientist at SRF Consulting said an application of RePlay can extend the service life of pavement up to seven years, depending on the condition of the pavement.

Where is RePlay being used? From 2011 to 2019, RePlay was used in 460 roadway projects across 50 Minnesota counties, according to AURI.

In addition to Minnesota, the bio-based product is being used in Pennsylvania, Nebraska and Iowa.

What's next for biobased asphalt preservation? Gosse said project collaborators are ready to work with transportation officials to implement bio-based transportation projects. In addition, AURI is exploring options to support new bio-based asphalt preservation projects.

“There is an opportunity for immediate economic benefit and environmental benefit to displacing petroleum products with long-term water and land protection opportunities,” Gosse said.

To learn more about AURI, visit auri.org. To learn more about the Minnesota Soybean Research and Promotion Council, visit mnsoybean.org. To learn more about the city of Hutchinson, visit ci.hutchinson.mn.us. To learn more about RePlay, visit biospantech.com/product/replay.

Kubat Willette is a Farm Progress digital content creator.