High temperature properties of rejuvenating recovered binder with rejuvenator, waste cooking and cotton seed oils

• Rejuvenator, waste cooking and cotton seed oils were employed for rejuvenation of RAP.
• High temperature characteristics of rejuvenated asphalt binder were tested.
• The used rejuvenated additives can reduce the viscosity value and fail temperature.
• Rejuvenator, cotton seed oil or waste cooking oil result in an increase of phase angle.

Rejuvenator, waste cooking and cotton seed oils contain a great amount of unsaturated fatty acids, similar to the light oil component of asphalt binder which usually decreased due to a long term aging procedure. Based on the rejuvenation theory and some related studies, rejuvenator, waste cooking and cotton seed oils can be used for asphalt regeneration. The objective of this study was to investigate the high temperature rheological properties of rejuvenating aged asphalt binder with rejuvenator, waste cooking and cotton seed oils. The materials used for this study included three sources of aged asphalt (recovered from reclaimed asphalt pavement), one virgin asphalt (PG 64-22), and three rejuvenating materials: rejuvenator, waste cooking and cotton seed oils with three percentages (0%, 5%, and 10% of rejuvenating asphalt). The used mass ratio of aged to virgin asphalt is 1:3 (i.e. 25% aged binder) in this study. The high temperature characteristics of these rejuvenated asphalts were tested including rutting resistance factor (phase angle and complex modulus), failure temperature and rotational viscosity. The results indicated that the rutting resistance factor and the complex modulus of rejuvenated binders decreased due to the addition of rejuvenator, cotton seed oil or waste cooking oil while their phase angles increased. In addition, the aged asphalt used a small amount of waste cooking oil or cotton seed oil can more easily achieve the demand of PG 64 binder in rutting resistance factor, phase angle, complex modulus and failure temperature of aged asphalt compared with rejuvenator. Finally, waste cooking oil or cotton seed oil can slightly reduce the viscosity value of the aged asphalt and thus decrease the mixing and compaction temperatures of the mixture.