Evaluation of internal structure of asphalt mixtures compacted using a virtual gyratory compactor

Computational models are increasingly being used to simulate the behavior of asphalt mixtures on account of their ability to conduct a broad range of parametric, sensitivity and probabilistic analyses. However, computational models rely on mix geometry as a starting point for any of these analyses, and methods to create such a geometry are either onerous or inaccurate. In this regard, a computational model using an open source "Bullet" physics engine was developed in the previous studies to virtually compact asphalt mixtures in a gyratory compactor using real 3D aggregate shapes. This present study evaluates the internal aggregate structure of asphalt mixtures compacted using the aforementioned computational model and compares with the laboratory compacted specimens. Four asphalt mixtures were compacted both in laboratory using the Superpave gyratory compactor and virtually using the computational model. Two different set of aggregate shapes were used in virtual compaction of an asphalt mixture. Results indicate that the aggregates preferred to align themselves both in laboratory compaction and virtual compaction. The difference in orientation plane was attributed to the differences in gyration of the mold versus top plate in the laboratory versus virtual compaction, respectively, which can be addressed in future by improving the simulation model.