Evaluation of the effects of gyratory and field compaction on asphalt mix internal structure

This study investigates the effect of gyratory and field compaction on the internal structure of asphalt mixtures. For this purpose, three new full-scale pavement test sections with different HMA mixes were selected for sampling loose material and field cores. Loose material was compacted using the gyratory compactor and adjusting several parameters, namely the gyration angle, compaction temperature and specimen geometry. Internal structure of the gyratory and field compacted specimens was quantified in terms of the aggregate contact points, orientation and segregation by means of 2-D image analysis. From the laboratory investigation it was demonstrated that the gyration angle and specimen geometry significantly affected the internal structure. The results also indicated that the field compaction produced similar internal structure in asphalt pavements and, especially, compaction with gyration angle of 1.45(o) best simulated the internal structure of field cores.