12 SPRING/SUMMER 2023 △ continued from page 11 ASSESSING SUSTAINABILITY All mixtures were designed using the balanced mix design (BMD) concept to provide equal or better performance than the associated control mixture. The BMD concept uses performance-related tests during mix design to incorporate performance into the materials selection and design process. Quantifying Greener Pavements in Virginia The purpose of the 2022 trials was to build on previous efforts undertaken by VTRC and VDOT on RPM and high RAP mixtures. The RPM trials specifically help evaluate the feasibility and process of recycling asphalt mixtures already containing recycled plastic waste. Results will highlight the impact of further recycling on the performance properties of such mixtures and the potential generation of hazardous emissions to the environment in the laboratory (during design), during production at the plant, and during placement in the field. The 2022 trial of high RAP with RA will also help validate the performance-based parameter(s) with threshold limits and criteria currently being established in-house to screen and differentiate compatible and non-compatible RA products for mixtures produced using locally available material in Virginia. Finally, VTRC also recently initiated an effort to quantify greener pavements in Virginia in response to the Federal Highway Administration (FHWA) Climate Challenge, with a major focus on quantifying — Currently, VDOT does not quantify the potential environmental benefits of using the technologies and practices adopted because the data required to do so either do not exist or do not exist in an open-source format. Therefore, there is a growing need to develop these background data to determine and communicate the environmental impacts and greenhouse gas (GHG) emissions from the production and use of [sustainable pavement] materials. emissions of sustainable pavements. Currently, VDOT does not quantify the potential environmental benefits of using the technologies and practices adopted because the data required to do so either do not exist or do not exist in an open-source format. Therefore, there is a growing need to develop these background data to determine and communicate the environmental impacts and greenhouse gas (GHG) emissions from the production and use of these materials. Relatedly, efforts will need to be raised to educate users, collect open-sourced data, modify and implement GHG accounting frameworks, and disseminate findings through case studies. The data generated in these trials will be used as seed data inputs to conduct life cycle assessments (LCAs) and develop corresponding environmental product declarations (EPDs) as part of the FHWA Climate Challenge effort. Acknowledgments These important and extensive trials were accomplished with the contribution and hard work of several parties. We wish to extend our appreciation to Thomas Schinkel (District Materials Engineer, VDOT’s Richmond District) and David Shiells (District Materials Engineer, VDOT’s Northern Virginia District) for allowing these trials to occur in their districts. Also, to Travis Cable (Vice President of Quality Control) and his team at Colony Construction, Inc.; Aleksandra Wojcik (Quality Control Manager), Rob Schwear (Area Operations Manager) and their team at Allan Myers; and Danny Poole (Director of Quality Assurance) and his team at Superior Paving Corp. We also received support from additional personnel in VDOT’s Richmond District, VDOT’s Northern Virginia District, and VDOT’s Materials Division, so thank you. In addition, the assistance and support provided by the plastic suppliers MacRebur Ltd, Kao Chemicals, NVI Advanced Material Group, and GreenMantra Technologies; the recycling agent supplier of Sripath Technologies®, LLC; and the supplier of fiber feeders/ machines, Hi-Tech Asphalt Solutions, are greatly appreciated. Finally, thank you to VTRC leadership and staff for their continuous support of such innovative efforts. Figure 3. Production, Paving Operations, and Placement of Mixture with High Content of Reclaimed Asphalt Pavement and Recycling Agent Recycling Agent
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