Use of angle of repose of aggregates as an indicator of asphalt concrete properties

Morphological characteristics of aggregates play a significant role in overall response of asphalt concrete under mechanical loading. Due to its simplicity, minimal resources, and less testing time, Angle of Repose (AoR) has been used by various researchers to characterize morphological characteristics of aggregate. This work presents the results of an experimental study to develop interrelationship between AoR and macroscopic response of Asphalt Concrete (AC). For this purpose, (i) aggregates were artificially smoothened through abrasion to different levels of texture/smoothness, and (ii) AoR was measured. Three AC mixtures were prepared using these processed aggregates and were tested for volumetric, strength and flow properties. A strong positive correlation was found between AoR and Marshall parameters (stability, Marshall quotient, retained stability, retained Marshall quotient). A weak negative correlation was found between AoR and Marshall flow. This can be attributed to interparticle resistance developed during compaction and mechanical loading. Thus, it can be concluded that AoR can be effectively used to capture changes in aggregate morphology and AC response.