Recycled asphalt pavement (RAP) usage has become a vital source of bituminous roads production in perspective of cost and energy saving. Asphalt mixtures when incorporating a higher amount of RAP contents, the main concern is possible to low thermal cracking. For minimizing this thermal cracking, numerous rejuvenators have been used in past. The objective of this research is to study microstructure induced on the binder surfaces when crude palm oil (CPO) was blended with fresh as well-aged binder by using a high-resolution electron microscope at nano-scale. For investigating the surface structure, field emission scanning electron microscopy (FESEM) along with the energy dispersive x-ray spectroscopy (EDX) was done. The results showed that for virgin binder worm or tube structure was formed. It can be speculated that the tube structure may be caused by the volatiles evaporation when an electron beam is thrown on the surface. For aged binder, the angular structure was more prominent. The structure on the aged binder shows the stiff in nature. The addition of CPO with the aged binder reduced that angular surface making it less stiff and smoother. © 2024 American Institute of Physics Inc.. All rights reserved.