Computation of Aggregate Contact Points, Orientation and Segregation in Asphalt Specimens Using their X-ray CT Images
ABSTRACT. In this paper, image processing and analysis methods are presented to extract the individual aggregate properties from the x-ray CT images of asphalt specimens. First, a technique was presented (and validated) to segment the clustered aggregates due to elevated pixel intensities near the aggregate-to-aggregate contacts in the image. Once the aggregates were segmented, aggregate-to-aggregate contact points, 3D orientation and segregation of aggregates were analyzed for asphalt specimens compacted at different levels.
KEYWORDS: x-ray CT, aggregate, asphalt mixture, image processing
Internal structure characteristics related to the aggregate skeleton significantly influence the long-term performance and sustainability of asphalt pavements. Packing and compaction of aggregates within asphalt mixtures can be very important for the overall performance of the system. However, in asphalt mixtures, direct quantification of internal packing characteristics of aggregates in 3D has been very limited. One method of direct quantification of 3D microstructures is through imaging techniques such as x-ray Computed Tomography (CT). Previous studies have utilized x-ray CT to quantify the air void distribution (Masad et al. ...