Researchers at VTRC and the Virginia Tech Transportation Institute (VTTI), in partnership with VDOT, are taking the challenge of road improvements seriously.
In 2015, VDOT invested in a heavy vehicle simulator (HVS), a massive piece of testing equipment that applies a heavily weighted load to pavement test sections. One of only 6 in the United States, the HVS is housed at VTTI as the centerpiece of the accelerated pavement testing program. The machine’s wheel assembly runs back and forth continuously over 100 foot stretches of test pavement over several months, simulating vehicular traffic and even heavy tractor trailer loads. It can apply approximately 13,000 unidirectional passes in a 24-hour period.
VTRC colleagues, Benjamin Bowers, PhD, Research Scientist, and Brian Diefenderfer, PhD, Associate Principle Research Scientist, are working with Gerardo Flintsch, PhD, Civil and Environmental Engineering at Virginia Tech, to explore various test configurations:
- Lanes 1 and 2 have been constructed with a 100% recycled base layer and varying asphalt surface thicknesses to determine how thin the top layer can be and still deliver acceptable performance
- Lanes 3 and 4 are validating asphalt mix design changes
- Lanes 5 and 6 are testing strategies to reduce reflective cracking that occurs when new asphalt is laid over jointed concrete pavement.
Bowers explained why the HVS represents such an important advancement in paving innovation. “The HVS mimics real conditions so that we can determine the impacts of regular road traffic without lane closures or jeopardizing the safety of our workers and the public. And because we achieve results in 3-5 months rather than 2-3 years, we can implement these solutions quickly. Since the shorter testing times reduce costs, we can look to extend the use of these improved paving materials onto secondary roads and into rural areas.”
Kevin Wright, Research Implementation Coordinator with VDOT, agreed. “Our goal at VDOT is to improve our roadways and extend their life. The HVS is allowing us to develop longer-wearing pavements, helping to reduce overall costs and minimize environmental impacts. Ultimately, this means less disruption to the public while delivering sustainable solutions.”
The Virginia Transportation Research Council (VTRC) is one of the country’s leading transportation research centers. Specializing in applied research to support VDOT, its scientists and engineers also provide technical consulting and training to promote innovations in structures, pavements, materials, safety, operations, traffic engineering, planning, environmental, and economic issues.
The goal of VTRC is to conduct research that enables VDOT to deliver transportation initiatives that save lives, save time and save money, while protecting Virginia’s environment.