Effect of Gradation and Morphological Characteristics of Aggregates on Mechanical Properties of Bituminous Concrete and Dense Bituminous Macadam

In present study, two different sizes i.e., gradation I and II, for both bituminous concrete (BC) and dense bituminous macadam (DBM) of aggregates are castoff to investigate the influence of gradation on four different shapes (i.e., round, angular, flaky and elongated). Subsequently, traditional methods and 3D optical scanner image analysis were infringed for morphological characteristics of the aggregates. In addition, scanning electron microscopy and energy dispersive X-ray spectroscopy analysis were carried out for determination of mineral composition and microstructure of aggregates. The results (from total 32 set of experiments as per factorial design) resolute that aggregate morphological characteristic is intensely associated with the resistance to permanent deformation of bituminous mixtures, and BC II and DBM II gradation represent better performance than BC I and DBM I. Furthermore, 3D optical scanner demonstrates a more direct and scientific evaluation of aggregate’s morphologic characteristics that present a superior relationship between the mixture performances than traditional techniques. It was found that the aggregate chemical composition, surface texture and filler microscopic morphological characteristics are highly associated with mechanical response and performance of bituminous mixtures.