Effect of the softer binder on the performance of repeated RAP binder

A softer binder as the rejuvenator was added into the repeated reclaimed asphalt pavement (RRAP) binder to study the rejuvenating mechanism. Consistency properties, chemical oxidation degree, rheological properties, microscopic morphology and mechanics were studied using consistency tests, fourier transform infrared spectroscopy (FTIR), dynamic shear rheometer (DSR) and atomic force microscope (AFM). With increase in rejuvenator concentration, consistency properties, rheological properties and micro mechanical properties were improved and the oxidation degree was declined. Meanwhile the microstructures changed significantly. Results show that properties of the RRAP binder can be restored with the addition of the softer binder and the appropriate proportion is 40%.