Abstract
The field excavation of asphalt pavement was conducted in the expressways where East Nippon Expressway Company manage, to investigate how the aging effects from surface to subgrade layer. From the result of this investigations, it is evidenced that the aging of asphalt has attained to not only the surface but also the asphalt stabilization subgrade, and the penetration of asphalt in porous asphalt mixture decreased more rapidly than that of dense-graded asphalt mixture. As a result of further laboratory test based on the aforementioned investigation results, it is indicated that conducting accelerated aging test considering mixture type is necessary to simulate the aging ofthe asphalt arising on the actual road.
