RAF is working with technical leaders in the asphalt industry to provide uniformity in specifications and to provide information and performance property characteristics that are unique to binders made with RTR particulate.

State Highway agencies have been using polymer modified asphalt in highway construction for many years. A new tool used to evaluate the polymer properties in the asphalt binder is the multi-step creep and recovery (MSCR) test. The MSCR effectively determines the polymer network in the asphalt binder. The MSCR properties were developed using typical polymers used in the industry today such as SBS, SB and Elvaloy. There has been a significant increase in interest to use recycled tire rubber as a modifier in asphalt binder. The high cost of polymer and availability has caused issues in the paving industry. An evaluation of the MSCR properties of RTR modified binder is needed to provide input for specification properties.

RAF is considering proposals to collect data on the MSCR properties of RTR modified binders and analysis to determine the effect of RTR on the percent recovery. This data and analysis could be used to develop minimum MSCR percent recovery requirements for RTR modified binders, indicating its presence in the binder and providing the elastic response information highway agencies desire.

The intent of the work is to provide an analysis on the effect of RTR on the MSCR percent recovery properties. The data will be formatted to fit into the existing AASHTO MP 19 specifications. Recommendations on how to adjust the current MSCR requirement to address the RTR modified binder properties will be developed and supported by the data analysis.

Through technical work such as the MSCR proposal, RAF is able to meet its goals and serve its community needs. The RAF is a research foundation dedicated to the science and practical use of recycled tire rubber in asphalt. RAF serves as a comprehensive, expert resource to provide technical knowledge and awareness that will enhance the development and broad use of rubberized asphalt. The foundation is comprised of renowned international experts from academia, government and industry who are leading the scientific development of recycled rubber for asphalt applications.

Join RAF to provide technical excellence in the use of RTR modifiers and to support the development of the MSCR curve for rubberized asphalt.

RAF recognizes that with your support, the use of rubberized asphalt as a beneficial engineering material can continue to grow around the world.

As a member, you will experience numerous benefits and remain at the forefront of information and new discoveries as RAF works to ensure the benefits of rubberized asphalt garner widespread understanding based on good science and research.