This article first appeared in the FHWA’s EDC News Weekly Newsletter of August 26th, 2021 and featured NJDOT’s application of high performance thin overlays (HPTO) as a pavement preservation tool.
Targeted Overlay Pavement Solutions
Last week, we discussed a case study involving bonded concrete overlays, part of the Targeted Overlay Pavement Solutions (TOPS) toolbox. This week, we’ll look at how New Jersey has used high performance thin overlays (HPTO) successfully as a pavement preservation tool.
Since 2015, NJDOT has used HPTO on more than 1,000 lane miles to seal pavement and improve ride quality. Benefits include short road closures reducing impact on traffic, and addition of approximately 10 years of service life. Timing of the application is crucial. A Rutgers University study found applying HPTO to pavements while they are still in “good” condition more than doubles the service life compared to applying the product to pavements in “fair” condition.
Contractors who construct NJDOT projects have not reported constructability issues or complaints about the mix. NJDOT believes including performance requirements for the mixture, understanding treatment selection and application timing, and requiring project engineers to approve specifications are key factors in the success of HPTO as a pavement preservation tool.
Based on this research and evaluation of projects to date, NJDOT considers HPTO a cost-effective solution that provides a safe, smooth, crack and rut resistant surface that extends the life of the pavement and causes minimal impact on the road users and environment during construction.