Update:

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Research conducted
In 2017 we applied a soy-based road dust control agent, developed at NDSU, to a gravel road that also contained reclaimed asphalt pavement (RAP) millings. After a few weeks, the loose gravel surface transformed into a firm, asphalt-like surface indicating that our soy material could rejuvenate RAP. In FY19 we performed a systematic study of the soy/RAP rejuvenation with the goal of determining the optimal soy/RAP mix ratio that could create a suitable construction material.
In the lab, we extracted the aged asphalt binder from RAP millings and treated it with increasing levels of our soy material. The treated samples were analyzed by various methods to determine the change in viscosity, stiffness, glass transition temperature and strength relative to an untreated control. Finally, the soy treated binders were recombined with gravel, formed into cylinders, and compression tested.

Why the research is important to ND soybean farmers
Creating new uses for soybeans is important for ND soybean farmers as it helps to expand the market for soybeans in the United States and reduces the reliance on vulnerable foreign markets. Our soy-based dust control material has great potential for road dust control and RAP rejuvenation, both of which are large US markets. If our soy material replaced just 10% of road treatments for dust control and treated 5% of the yearly RAP generated in the US, we could estimate an annual combined soybean usage of ~50 million bushels.

Final findings of the research
The results from the NDSU Asphalt Testing Lab (Dr. Ying Huang, Mu’ath Al-Tarawneh) indicate that 10% of our soy product added to aged asphalt binder is the optimal amount. At this concentration, the rejuvenated binder has increased flexibility, improved low temperature performance, reduced viscosity and increased strength when re-combined with aggregate. Although, this research required the binder to be separated from the aggregate, in reality, the soy product would be added directly to the RAP millings. Going forward, we can now accurately treat larger quantities of RAP for future road testing.

Benefits/Recommendations to North Dakota soybean farmers and industry
Expanding markets for soybeans is more important than ever and our product has the potential to do just that with a clear benefit to the North Dakota farming industry. ND farmers could help make this a reality by purchasing soy-based products for their own operations and encouraging their local counties to do the same.