The use of Reclaimed Asphalt Pavement (RAP) in asphalt mixtures has several benefits, such as reducing the consumption of virgin materials and protecting the environment. However, as high RAP content (e.g., 50%) is used, asphalt mixtures become brittle so that premature failure (cracking) may occur. To improve the cracking resistance of asphalt mixtures with high RAP contents, one of the approaches considered is the use of rejuvenators. Such rejuvenators, when used in high RAP asphalt mixtures, counteract the effects of the aged RAP binder and may have an impact on the volumetric properties of the mixtures.

Rejuvenators generally contains a high proportion of maltene constituents—napthenic or polar aromatic fractions—that help re-balance the composition of the aged binder. The purpose of using rejuvenator is to improve the maltene content of the RAP binder that has been lost due to oxidation over years of use. The lower maltene content in RAP binder causes the asphaltene component to flocculate, which leads to a greater susceptibility to cracking. Increasing the maltene content through the addition of rejuvenators allows the asphaltenes to move freely, improving the flow properties of the binder.