Asphalt pavements play a crucial role in constructing durable and sustainable road infrastructure. In recent years, with the advancement of sustainability and circular economy goals, reclaimed asphalt (RA) has been widely used in road construction. While the use of RA effectively reduces resource consumption and environmental impact, research on the fatigue and healing performance of asphalt mixtures and binders with high RA content remains relatively limited. This study aims to evaluate the healing performance of binder components from three asphalt mixtures commonly used in the base layers of Dutch pavements, employing multiple healing test protocols and healing indices. Two of these binders contain a high proportion of RA bitumen.

To achieve the research objectives, fatigue and healing tests were conducted on three different asphalt binders: Binder 1, composed entirely of fresh bitumen; Binder 2, a blend of high RA content bitumen with softer fresh bitumen; and Binder 3, which includes high RA bitumen content, fresh bitumen, and the rejuvenator. Fatigue performance was evaluated using Time Sweep (TS) and Linear Amplitude Sweep (LAS) tests to determine the fatigue life of each binder. Additionally, healing performance was assessed through single-rest period and multiple-rest period Time Sweep Healing (TS-H) tests, as well as Linear Amplitude Sweep Healing (LAS-H) tests. To evaluate healing performance, two different indices were used: the Healing Shift Factor (SFh), based on fatigue life extension, and the Healing Index (HI), based on modulus recovery.

The differences between single and multiple rest periods TS-H tests highlight the limitations of single rest period tests in fully capturing material healing capacity, indicating that more complex loading patterns should be explored for more comprehensive assessments. The variations in healing potential results across different test protocols and indices suggest that the healing performance of binders is highly sensitive to test protocol and indices selection.

Based on the described approach, a better understanding of the healing performance of different asphalt binders is achieved. Conclusions and future recommendations for research in this field were provided at the end of this research.