Imaging Based Evaluation of Coarse Aggregate Size and Shape Properties Affecting Pavement Performance

This paper defines and presents imaging based aggregate morphological shape indices of 39 coarse aggregate materials recently collected in a pool fund research study. Using a three-dimensional imaging system, University of Illinois Aggregate Image Analyzer (UIAIA) and following test procedures previously established for the UIAIA, imaging based morphological indices were defined for the three-dimensional shape, size, angularity, and surface texture properties from the acquired images of the coarse aggregate particles. Using statistical techniques, four categories were established for commonly used coarse aggregate types based on image analysis shape property data. A definite relationship was shown to exist between coarse aggregate angularity and surface texture imaging indices, which were also linked to laboratory and field performances of asphalt mixtures.