Three dimensional particles identification and shape parameters research on coarse aggregates of asphalt mixture using X-ray CT images

In this paper a series of digital image processing methods were adopted for getting separated coarse aggregates from asphalt mixture specimen using high-resolution X-ray Computed Tomography （CT） images. The existing three dimensional （3D） particles matching methods based on two dimensional （2D） continuous cross- sections were analyzed and a new ＇ overlap area method＇ was presented. After the 3D particles were extracted one by one successfully, the basic parameters of each aggregate： perimeter, area, surface area, and volume were calculated by chain code method. Finally, the 3D mass center coordinates and the sphericity index were introduced.