How can an asphalt mixture incorporate recycled plastic while maintaining the performance a road requires? The NewRoad pilot project on PR-177, in the Los Filtros area of Bayamón, provides local experience and laboratory results to explore that question.
The project incorporated 200 tons of asphalt mixture containing NewRoad in collaboration with Professional Asphalt LLC. Samples evaluated by the National Center for Asphalt Technology (NCAT) showed less rutting in the Hamburg test than the control mixture. At 20,000 wheel passes, the difference was approximately 37%.
The Challenge of Improving Pavement Performance
For those who design and carry out road projects, selecting a mixture requires considering its resistance to rutting, moisture susceptibility, and cracking tolerance. The condition of the existing layers and the quality of construction are also part of that assessment.
In this context, using plastic waste presents an opportunity: incorporating a recovered material into a road application and verifying its performance through testing. The PR-177 project helps connect that discussion to conditions and operations in Puerto Rico.
What Is NewRoad
NewRoad is a hybrid polymer asphalt additive made from recycled plastics. It is incorporated into asphalt mixtures to modify their performance and provide an application for materials that might otherwise end up in landfills.
Its evaluation should consider the mixture design, dosage, and requirements of each project. Test results allow a specific formulation to be analyzed, without replacing technical validation for other applications.
A Local Application in Bayamón
The Los Filtros pilot section used a dosage of 4 pounds of NewRoad per ton of mixture. According to the project documentation, incorporation at the Professional Asphalt plant and paving operations proceeded without issues.
Samples collected at the plant were sent to NCAT to evaluate permanent deformation and moisture damage using the Hamburg test, binder grading, and cracking resistance using IDEAL-CT.
What the Results Show
The Hamburg test subjects samples to repeated wheel passes in the presence of water at an elevated temperature. In the comparison presented, the NewRoad mixture showed a lower rut depth at both measurement points.
|
Indicator |
Control Mixture |
NewRoad Mixture |
|
Rut depth at 10,000 wheel passes |
4.02 mm |
3.72 mm |
|
Rut depth at 20,000 wheel passes |
7.21 mm |
4.56 mm |
|
Onset of moisture-induced stripping |
16,100 wheel passes in one sample |
Not observed through 20,000 wheel passes |
Source: NCAT results and comparison included in the project’s technical presentation. Rut depths correspond to the reported averages.
At 20,000 wheel passes, the reduction from 7.21 mm to 4.56 mm represents approximately 37% less rutting. This percentage describes the test result; it does not represent a demonstrated percentage increase in the road’s service life.
Cracking Resistance and Binder Grading
In the IDEAL-CT test, the six NewRoad samples achieved an average CT index of 161.3, with values ranging from 93.8 to 228.0. These results characterize the cracking tolerance of the samples tested. Acceptance should be evaluated against the specification applicable to each project.
NCAT reported a formal binder grade of PG 70-22. Although one measurement of the RTFO-aged binder reached 76.3 °C, that individual result does not constitute a complete PG 76 grade.
The Opportunity for Puerto Rico
This case provides evidence to evaluate mixtures containing recycled plastic for future local applications. It also presents a potential opportunity for manufacturing development in Puerto Rico. Local production, associated jobs, and waste reduction at scale would depend on implementation of the model and the availability of suitable feedstock.
To estimate the economic benefit, each project needs to compare mixture costs, placement costs, and expected maintenance. The available results support a technical evaluation, but do not yet establish specific savings or guarantee additional years of service.
Learn How to Evaluate NewRoad for Your Project
Are you evaluating materials for a road project in Puerto Rico? Contact the Caribbean Sign Supply team to learn more about NewRoad and discuss the technical information needed for your application.
Request Information About NewRoad