VAA Virginia Asphalt Spring/Summer 2021

30 SPRING/SUMMER 2021 VTRC PROGRAM OVERVIEW SPRING 2021 Kevin McGhee, P.E., Associate Director of Research-Pavements, VTRC Introduction and Staff Changes Even as much of the world retreated to a more “virtual” existence last spring, researchers from the Virginia Transporta- tion Research Council's (VTRC) Pavements team strapped on their face coverings and climbed into (separate) cars and trucks and joined contractor quality control and VDOT quality assurance staff to make sure that a pandemic did not interrupt valuable asphalt research. Support from the highest levels of VDOT also enabled the research program to make a critical hire when most offices were frozen or shrinking under the global economic contraction. In September of 2020, VTRC welcomed Danny Martinez as our very first Technical Resource Manager. He joined the VTRC staff after completing his Master of Science Degree in Civil Engineering from the University of Auburn. While at Auburn, Danny worked for the National Center for Asphalt Technology (NCAT). While there, he continued to build on private-sector experience to support NCAT's applied research on pavement preservation and balanced mix design (BMD). As the pavement program’s Technical Resource Manager, Danny will have the considerable challenge of coordinating technical support for six very demanding research scientists (and their associate director). The resources under his charge include two top-notch salaried technicians, a varying number of wage staff, numerous laboratory spaces, and state-of-the-art equipment that provide for both basic and advanced testing of conventional and not-so-conventional asphalt binders and mixtures. Danny is actively recruiting to fill several vacancies among our wage staff. He will also be busy working with scientists and technicians to replace several pieces of aging laboratory equipment and ensure everyone is trained and ready to support another busy construction season. Balanced Mix Design (BMD) Research Support for BMD Pilot Projects As spring arrives this year, things continue to look much like last—face coverings and social distancing—but with hopes for a late summer/early fall that looks and feels more like what we used to consider normal. Regardless, our research program will press on with support for many existing initiatives and several new ones. Most visible among the continued activities include support for the BMD initiative, which involves several import- ant sub-projects. Stacey Diefenderfer, with help from Ilker Boz, Jhony Habbouche, and laboratory and field staff, will continue to provide support for both the scheduled BMD pilot projects, as well as any less-formal work-order trials that may get “negotiated” between forward-looking producers and the districts. Indirect Tension Test for Rutting Potential Ilker Boz, with help from the University of Virginia, is leading research that explores the indirect tensile test (IDT) to screen asphalt mixtures for rutting potential. If successful, contractors may have an economical way to tinker with design variants when they don’t have ready access to the Asphalt Pavement Analyzer (required for VDOT’s standard perfor- mance test for rutting resistance). Early results are promising, with some findings suggesting applications beyond just screening designs for rutting susceptibility. Round Robin for IDT Cracking Test Jhony Habbouche is working with Mike Dudley from the Virginia Asphalt Associa- tion to coordinate an early-season round- robin experiment centered on the primary cracking test for BMD. Jhony and Mike, with help from Stacey and Ilker, are working with a third-party laboratory to prepare a mixture that will be distributed to more than forty laboratories were specimens will be prepared and tested. This experiment, the second of two phases, will explore the effect of equipment type and loading rate, the impact of specimen fabrication/preparation, along with other factors such as test error, single operator variability, and multi-laboratory variabil- ity on the testing that characterizes cracking susceptibility of asphalt mixtures. If you operate a laboratory that supports asphalt production in Virginia, expect to receive material from Jhony and Mike by late spring. Review and Acceptance of Recycling Agents Jhony is continuing to lead research with North Carolina State University to better understand the myriad of chemistry Figure 1: Danny Martinez, VTRC Technical Resource Manager (Pictured Here with Dr. Ray Brown, Former Director of NCAT)