ABSTRACT
There are not few researches focusing on the morphology of old aggregates in reclaimed asphalt pavement (RAP). However, the morphological characteristic of RAP itself should have been paid more attention in view of its real state in the reclaimed mixtures. In this study, a 3D scanning system was used to model the RAP and then digital model processing was implemented to determine some morphological parameters i.e. shape factor (SF), ellipsoidality (EP) and point-distance standard deviation (PDSD) by using Unigraphics NX and Matlab software. The influence of preprocessing measure named refined decomposition and RAP size on the morphological characteristics were considered in this study. The obtained results show that RAP materials show shape classified as normal level with the SF of 0.9~1.1, obvious angularity with the EP lower than 0.6 and relatively small surface roughness with PDSD below 0.05. As the RAP size decreases, the shape of RAP is flakier, the angularity is greater, but the surface roughness is not monotonically varied. In addition, the angularity and surface roughness of RAP is reduced, and the shape of RAP is closer to be needle-like after the refined decomposition process.
