AGGREGATE ORIENTATION AND SEGREGATION IN ASPHALT CONCRETE

Abstract

Asphalt pavement is a complex material that consists of aggregates, air voids and asphalt. The performance of asphalt concrete mixtures is influenced by its internal structure, which refers to the arrangement of aggregates and their associated voids. This paper focuses on developing computer automated image analysis procedures and parameters to quantify the aggregate orientation and segregation in asphalt concrete mixes. Aggregate orientation is described by a directional function with its components determined experimentally. Aggregate segregation is quantified by means of spatial statistics. The new parameters of orientation and segregation are used to study the variation of aggregate orientation and segregation in an asphalt concrete mix during compaction using the Superpave Gyratory Compactor (SGC). The measured parameters of the SGC compacted specimens are compared with those of field cores