Rapid performance grade assessment of virgin and recycled asphalt binders using a rheometer

The Performance Grading (PG) criterion plays a pivotal role in grading bitumen for various applications, such as trading, road construction, and research and development works. The definition of high PG temperature hinges on the point where the Superpave rutting parameter, G*/sin\(\delta \), attains a value of 1 kPa. In this study, we present a novel mathematical model developed to accurately predict the high PG temperature of bitumen. To ascertain the PG temperature of the bitumen, we conducted the Original Binder Grading (OBG) test using a rheometer. Leveraging the data obtained from this test, our developed model forecasts the true high PG temperature based on the average value of G*/sin\(\delta \) measured at 64 °C. Notably, the model yields rapid results within approximately 15 minutes after initiating the OBG test, which effectively reduces test duration and empowers users to manage their work more efficiently. We anticipate that this model will be readily embraced by rheometer manufacturing industries, as it provides a direct and reliable means of determining the bitumen’s high PG temperature. This technological advancement promises to enhance testing procedures, streamline research, and support better decision-making processes across the bitumen industry. However, the model is not validated for polymer-modified binders and should be applied to unmodified binders only.