A blending efficiency model for virgin and aged binders in recycled asphalt mixtures based on blending temperature and duration

The degree of blending of reclaimed asphalt pavement (RAP) binder is profoundly influencing the performance of asphalt mixtures containing RAP. Hence, it is essential to know the amount of RAP binder mobilized into the mixture to produce more durable asphalt mixtures. However, understanding the factors affecting the degree of blending and quantifying the degree of blending is still an open problem for researchers. This study investigates the effect of several factors such as blending method, blending temperature, blending duration, and RAP content on the degree of blending using Fourier Transform Infrared Spectroscopy (FTIR) analysis of the extracted binder from mixtures. It is revealed that the blending method, blending temperature, and blending duration have a significant influence on the degree of blending. The study revealed that prolonged blending durations and elevated mixing temperatures could improve the degree of blending. The amount of RAP in the mixture has little or no influence on the degree of blending. Further, based on the results, a blending chart is developed to determine the degree of blending with regard to blending duration and blending temperature.