Fine Aggregate Angularity Effects on Rutting Resistance of Asphalt Mixture

Fine Aggregate Angularity (FAA) has been identified as one of the important aggregate properties contributing to the stability of Hot Mix Asphalt (HMA) and its resistance against permanent deformation. The performance of dense graded asphalt mixture is significantly influenced by the shape, angularity and surface texture of fine aggregates. This study determines the FAA for different types of aggregates namely granite and natural sand and evaluates the rutting resistance of AC 10 mixture added with the aforementioned aggregates. Marshall test and wheel tracking test were carried out in order to assess stability and rutting resistance. It was found from FAA test, crushed granite has higher percentage of FAA (46%) compared to natural sand (37%). With higher FAA value, crushed granite mix was found to have better stability, stiffness, and flow compared to specimen with natural sand. From wheel tracking test, it was observed that the rut depth for specimen with crushed granite is lower compared to specimen with natural sand. Therefore it can be concluded that fine aggregates with more angular shape, provides better stability and increase the rutting resistance.