Katie Johnson

The Vermont Agency of Transportation recently evaluated the performance of a high-friction bridge deck overlay system that also functions as a waterproofing membrane. The quick-curing overlay consists of an aggregate chip seal affixed with a synthetic polymer epoxy. Five years after application on a low-volume bridge, annual site visits and structures inspections have shown the bridge and overlay to be in good condition, and the system has provided good skid resistance and waterproofing.

Read the report: Assessment of Poly-Carb Flexogrid Bridge Deck Overlay System, April 2019.

TRB has published a new E-Circular that provides an overview of the current state of the practice for structural monitoring technologies. Chapters address the purpose and value of structural monitoring; when to consider the use of structural monitoring; types of sensor technologies; implementation; transforming data into knowledge; ensuring a financial return from a structural monitoring project; and frequently asked questions.

Read the report: Structural Monitoring, June 2019.

Photo courtesy of Oregon DOT.

In 2014, Washington State DOT began constructing hot chip seals, which use an asphalt binder applied at 275 to 370 F and can be opened to traffic at normal operating speeds as soon as the binder has cooled. WSDOT recently conducted a construction and performance review of 11 hot chip seal projects, finding that most were performing well. The study developed construction recommendations for future projects.

Read the research report: Review of Hot Bituminous Surface Treatments in Washington State, January 2019.

In a recent study, Minnesota DOT researchers used lab and field tests to evaluate blends of recycled asphalt pavement (RAP) and virgin aggregate for use as gravel road surface layers. Maintenance costs for a 50% RAP blend and a 100% virgin aggregate surface were compared as part of an economic analysis, and two field studies analyzed the performance of blends with 15% to 80% RAP content.

Read the research report: Optimal RAP Content for Minnesota Gravel Roads, March 2019.

Vermont Agency of Transportation recently tested a lower-cost pavement maintenance approach, repaving a 40-inch-wide area along the right wheel path in each direction of a deteriorated roadway rather than repaving the entire surface. The treatment was successful, reducing rutting and cracking and extending the pavement’s service life.

Read the research report: Assessment of the 40″ Wide Paving Skid Box for Preventative Maintenance, December 2018.

Researchers for Minnesota DOT and the Minnesota Local Road Research Board have developed a spreadsheet tool to help local agencies effectively track and manage gravel roads. Designed to be flexible and customizable, the tool can be used to keep all maintenance and construction data about a gravel road system, as well as track costs.

See the project page: Gravel Road Management Tool, March 2019.