## 2 Literature Review
The objective of publication [30] is to provide a methodology for determining the degree of partial blending in high RAP mixtures. When RAP is mixed with virgin aggregates and virgin binder, partial blending of RAP binder with virgin binder develops in the HMA. As the degree of blending between the RAP and the virgin materials is not known, authorities limit the amount of RAP. The temperature characteristics of RHMA mixtures were studied through viscosity-temperature dependency of asphalt binders and temperature storage stability of blended mixtures [31]. The characteristics of temperature storage stability would be greatly influenced by the preheated temperatures of various components in asphalt mixtures. The results showed that the control optimization of RHMA mixture could lead to good rheological properties of asphalt binder containing reclaimed (old) and fresh (new) asphalt binder. The properties of the old bituminous binder are restored in bitumen films, the thickness of which depends on the size (diameter) of the mineral grains. Only the optimal amount of aggregate (old and new) binder allows to obtain the best properties of the regenerated asphalt mixture. Excess and deficiency of aggregate binder deteriorates the properties of RHMA mixture. The design of the bitumen dosing system of the asphalt mixer and its management has a significant influence on the increase in the amount of bituminous binder in the produced asphalt mix from the deviations from the JMF [32]. The average bitumen film thickness (BFT) is not a measured physical property. This parameter is calculated as material's volumetric characteristics and gradation [33]. Another computational method significantly improves the current conventional method for the asphalt film thickness calculation because grain shape factors and flat surface factors for sieve sizes are considered [33]. The field and laboratory experimental data both show that the bitumen film thickness is a significant factor influencing the rutting performance for asphalt mixtures. The research results [34] show that there is a dependence between the thickness of the bituminous film of the aggregate specific surfaces and the residual deformation. Mixtures with greater amounts of RAP are enhanced by adding rejuvenator additives. The use of suitable rejuvenators allows us to refine the properties of the old binder and the percentage of RAP in recycled asphalt mixture could be increased [9]. Recycled asphalt mixtures can also be produced using a significant amount of different waste materials [35]. The tests performed on the recycled asphalt mixtures containing lard imidazoline confirm the suitability of this agent for paving applications [36]. Rejuvenator is not a commonly used softening agent to be used in recycling of RAP. In study [37] Superpave mixtures containing RAP were designed on a base of rejuvenator and a soft binder. Later mixtures were evaluated regarding the volumetric result obtained the indirect tensile strength (ITS) of samples and assessing the mixtures for rutting using the asphalt pavement analyzer (APA). All Superpave mixtures with RAP content display the same quality properties as the two control virgin mixtures. A rejuvenator is an oil consistency material which restores RAP binder during hot recycling in plant. Ten potential locations for rejuvenator addition in asphalt plant were ranked and full-scale asphalt mixtures production experiment was performed to compare rejuvenator addition to cold RAP on conveyor belt versus addition to hot RAP in mixer [38; 39]. The effects of rejuvenator addition were evaluated to cold RAP before the RAP heating drum as opposed to the more conventional approach to add rejuvenator to hot RAP [38]. The minimum RAP content (min. RAP %) depends on the capability of AMP equipment to provide addition of the RAP accurately and consistently. The maximum amount of RAP (max.