A fundamental investigation was made on void structures of porous and coarse graded asphalt mixtures to combine their geometrical and physical characteristics. The voids in the mixture were visualized by filling them up with colored epoxy resin. The mixture was then cut after hardening and the sections were carefully imaged by a scanner connected to a personal computer system.
Every pixel of the scanned image of each section was digitized into three values and geometrical distributions of void, mineral aggregate, and binder are characterized as well as each content is quantified. It was found that each mixture has its own specific characteristics in images in cross sections, which is presumably related to its mixture properties.