Boxley Asphalt places 60% RAP mix at VTTI

After much planning and significant effort, Boxley Asphalt has completed the production and placement of a 60% RAP mix at VDOT’s Heavy Vehicle Simulator testbed at VTTI in Blacksburg, VA. This mix, designed by Andre Royal, Boxley’s Quality Assurance Manager, was the highest RAP content SUPERPAVE™ mix ever produced and placed for VDOT. The mix is part of VDOT’s effort to evaluate high RAP mixes and used the Balanced Mix Design, performance-based testing protocols in conjunction with the more standard volumetric based testing. As designed, the mix utilized a non-standard (at least for Virginia) PG58-28 and a rejuvenator to assist in meeting the performance test requirements. Researchers at the Virginia Transportation Research Council worked hand in hand with Boxley during both the design and production phases. Stacey Diefenderfer, Senior Research Scientist, stated, “while this has been one of the more challenging efforts we have undertaken as it relates to the use of high RAP, we hope that it will help us determine not only the limits of production but also assist in our drive towards performance-based mix design and acceptance.” The mix was placed in two lifts on lane 4 of the testbed, and preliminary results indicate that all field testing requirements were achieved. When asked about the project, Ken Arthur, Director of Asphalt Plants and Development for Boxley, said, “We thoroughly enjoyed this project. It is rewarding to work outside your comfort zone sometimes. It forces you to think outside the box and find creative solutions to problems.” Be on the lookout for more information regarding this project in the future.