Investigation of the reusability of end-of-life hot mix asphalts using bio-based materials as rejuvenators

The finite nature of natural resources and the growing global population make it imperative to use available resources efficiently, thereby necessitating the recycling of waste materials. In this context, the reuse of reclaimed asphalt pavement (RAP) obtained from asphalt surfaces has become increasingly important, both for environmental sustainability and economic benefit. This thesis investigates the potential for reusing aged RAP binder by improving it with various proportions of commercial and bio-based rejuvenators, and evaluates the performance of the resulting hot mix asphalt (HMA). B70/100 grade virgin bitumen was used as the reference binder, and mixtures were prepared using five different rejuvenators and three RAP content levels. The optimum binder content for each mixture was determined, followed by physical and mechanical testing. The findings show that appropriate amounts of rejuvenators enhance the technical and mechanical properties of RAP-containing mixtures. Furthermore, some rejuvenators were found to retain their performance even after long-term aging. These results suggest that this approach to utilizing waste materials can offer significant environmental and economic advantages to the asphalt industry and presents a strong alternative for developing sustainable pavement systems.