Governing mechanisms and practical implications of jamming transition in asphalt mixture packing

The stability of asphalt mixture packing is largely determined by the asphalt mixture design and compaction methods. This study investigates the jamming transition mechanisms during the asphalt mixtures packing behavior exposed to various compaction conditions by integrating laboratory experiments with discrete element method simulations. Confined, unconfined, and vibratory packing tests were performed to evaluate the effects of aggregate morphology, interparticle friction, binder adhesion, and vibration on the formation of jammed states. The results reveal that polygonal aggregates exhibit higher angles of repose than circular aggregates due to enhanced mechanical interlocking, while high temperatures weaken binder adhesion and reduce jammed-state stability. Increasing friction coefficients accelerates the jamming transition but limits particle rearrangement, resulting in looser packing structures. Compaction partially mitigates friction-induced variability through skeleton reorganization, yet optimal densification is achieved at the friction coefficient of 0.2, which balance particle mobility and load transfer resistance. The optimized vibratory loading significantly enhances initial packing, lowers final voids in mineral aggregate, and reduces the compaction impulse, achieving an equivalent temperature reduction of approximately 7.7 °C. These findings provide fundamental insights into the jamming transition of asphalt mixtures and offer practical guidance for improving construction protocols, reducing energy consumption, and enhancing pavement durability. • The packing behavior of asphalt mixtures underwent a jamming transition. • Aggregate shape, friction, adhesion, and temperature govern packing behavior. • A vibration–temperature equivalence framework quantifies energy-saving potential.