Preliminary characterization on the dynamic mechanism of asphalt mixture under on-site vibratory compaction

Compaction is the final critical step in the construction of asphalt pavements, but the dynamic response of the mixtures at the particle scale and its correlation with the compaction degree have received limited in-depth investigations. Based on the SmartRock sensor technique, this study is aimed for this inadequacy and to further understand the interaction characteristics (e.g., rolling speed, vibration range and contact width) between the steel drums and pavement surface during compaction at the particle scale. Meanwhile, the dynamic responses (i.e., acceleration frequency and amplitude) of the aggregates in the asphalt mixture were comprehensively investigated to establish the correlation between the acceleration amplitude and compaction degree of pavement. According to the results, the vibrating drum shows a higher compaction effectiveness than the driving drum in the z-direction. The acceleration frequency reflects the energy attenuation of vibration waves during vibrational compaction, and the attenuation of vibration acceleration is normally distributed with the distance from the SmartRock. Lastly, an empirical relationship was developed between the maximum acceleration and pavement compaction degree and can be used to provide reasonable estimations for the in-situ density. The findings are expected to shed light on the compaction mechanism of asphalt pavement, and to provide a potential approach/basis for improving the on-site quality control and decision-making during compaction.