Bitumen is composed of different types of hydrocarbons grouped into four components: saturated, aromatic, resins and asphaltenes. In order to maintain the original physicochemical structure, it is fundamental for each of these groups to be present in very specific ratios so as to ensure the good performance of the bitumen on the road.
Therefore, rejuvenated bitumen provides the fractions that aged bitumen has lost and regenerates until it recovers its original characteristics. The composition of the bitumen with rejuvenators is given by factors such as the working formula of the mixture to be recomposed, which is influenced by the recycling rate, physical characteristics, and the components to be provided to the aged binder to give it ideal characteristics.
The following premises must be taken into account in the design of this special bitumen for recycling:
- Restore the optimum composition of the aged bitumen to maintain the durability of the mixture.
- Take the aged bitumen to an adequacy consistency (penetration).
- Give the mixture the adequate binder content.