Variation of Aggregate Contacts Distribution in AC20 HMA Based on Digital Image Processing

Abstract:

In order to quantify the contacts between the aggregates,a new method based on digital image processing was put forward.For AC20 HMA,the amount of aggregates contacts and the features of the aggregates on all sample images acquired from 72 cut sections of rutting test samples were obtained through this method,and then the global contacts distribution rules of all aggregates,the local contacts distribution rules of each grades aggregates and the single particle contacts number distribution rules of each grades aggregates were acquired from statistical analysis.The variation of contacts amount on each images and influence factors including the content of aggregates above 2.36 mm (C>2.36),the fine index of aggregates above 2.36 mm (FI) and the segregation index(SI) were discussed.The internal relations of these three factors were as well analyzed.Contact features can be used for hot-mixture asphalt （HMA） gradation design as a referenced factor through these quantified analysis.