Project Details:

Soy Based Asphalt Rejuvenates

Parent Project: This is the first year of this project.
Checkoff Organization:North Dakota Soybean Council
Categories:Industrial use – Oil
Organization Project Code:QSSB
Project Year:2019
Lead Principal Investigator:Jim Bahr (North Dakota State University)
Co-Principal Investigators:

Contributing Organizations

Funding Institutions

Information and Results

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Project Summary

Recently, we have developed a soy based road dust suppressant with funding from the ND Soybean Council that was road tested over the summer of 2017. The product performed very well and after 3 months, there was very little dust generation relative to the calcium chloride control. During this test however, we noticed an interesting reaction between the soy-based dust control agent (soyDCA) and the reclaimed asphalt pavement (RAP) present in the gravel road surface. The result of which produced a smooth asphalt-like road surface that remained stable all summer. The purpose of this project will be to better understand the rejuvenating effect that our soyDCA has on RAP. This will be accomplished through laboratory testing on various mixtures of RAP including fresh asphalt binders. The knowledge gained from this effort will allow for larger field trials to be performed where the soyDCA is premixed with the RAP and applied to a section of roadway.
The re-use of discarded road waste is beneficial and commonly practiced in order to reduce the overall cost of road construction. RAP and recycled asphalt shingles are currently spread onto gravels roads to reduce dust and improve the stability of the road surface. We have seen from our road test that our soyDCA can enhance their use by acting as a binder and plasticizer. The goal of this research is to optimize the useful properties resulting from the combination of RAP and the soyDCA so that a field demonstration trial can be performed.

Project Objectives

The purpose of this research is to perform a systematic study of the observed RAP rejuvenating properties that the soy-based dust control agent exhibited during our field trials. The tests will be conducted in the asphalt research lab at NDSU and will include fresh asphalt as a standard for comparison. The knowledge gained from these experiments will allow us to better understand the rejuvenating properties of the soy-based dust control agent and provide a starting point for a field trial where the RAP is premixed with the soy-based agent and applied to a test section of road. The specific tasks required to accomplish this goal are listed below.
1) Mix RAP with soy based dust control agent at various levels.
2) Age the soy treated RAP.
3) Measure the mechanical properties of the soy treated RAP.
4) Extract the soy treated asphalt binder from the various samples of treated RAP.
5) Measure the mechanical properties of the extracted binders.
6) Compare the measurements from the soy treated samples to that of fresh asphalt.

Project Deliverables

Progress of Work

Updated May 8, 2019:
See uploaded report below

View uploaded report Word file

Updated July 23, 2019:

Final Project Results

Updated July 23, 2019:

View uploaded report Word file

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.

Benefit to Soybean Farmers

If the same soy-based dust control agent can be used to rejuvenate RAP, the market size and demand for this soy product will be increased through this new and expanded use. The result of which will create a new market for soybean oil as well as a new market for the waste glycerin generated by the biodiesel industry. These new uses for soybean oil will increase the demand for soybean oil in general and benefit soybean growers in North Dakota and nationwide.
Soybean bushel usage rate as a RAP rejuvenator could be 500-800 bushels per mile of road

Performance Metrics

Project Years

YearProject Title (each year)
2019Soy Based Asphalt Rejuvenates