From Interfacial Anchoring to Dissipative Synergy: A Multiscale Mechanism of Temperature-Adaptive Response in Large Waste-Tire Rubber

Abstract Recycled rubber–asphalt mixtures are temperature- and frequency-sensitive viscoelastic composites with potential for vibration damping. However, the molecular mechanisms linking interfacial load transfer and viscoelastic energy dissipation remain insufficiently understood, particularly when large waste-tire rubber particles are used as functional inclusions. In this study, a conventional AC-16 asphalt mixture and an AC-16-4 mixture containing 4-mesh rubber particles were investigated using accelerated loading tests, Burgers viscoelastic modeling, frequency-domain analysis, and molecular dynamics simulations. A multiscale mechanism is proposed to explain how interfacial anchoring, rubber-chain mobility, and viscoelastic damping jointly regulate the dynamic response of the rubber–asphalt composite system. The results show that AC-16-4 exhibits a stronger viscoelastic response and enhanced damping capacity within 0–20 °C. Around 10 °C, the strain growth rate reaches 157.1%, while the equivalent dynamic modulus decreases by 10.9%, suggesting a transition region where rubber-chain mobility, interfacial anchoring, and energy-transfer pathways begin to interact. At 20 °C, the delayed elastic recovery time of AC-16-4 is 39.64% longer than that of AC-16, and the dissipative frequency-domain response expands from 10–3–10–1 a.u./Hz to 10–2–100 a.u./Hz, indicating improved dynamic damping over a broader frequency range. Molecular dynamics simulations suggest favorable rubber–asphalt compatibility, with a solubility parameter difference of 0.6 MPa0.5 and a Flory–Huggins parameter of 0.3. The selective affinity between rubber and aromatics, together with SBR–asphaltene anchoring, contributes to the formation of a rigid–flexible interphase that restricts molecular migration while allowing chain relaxation and interfacial energy dissipation. The AC-16-4-SiO2 system achieves an energy dissipation of 130.4 kcal/mol at 15–20 °C and an energy conversion efficiency of 40.59% at 20 °C, 20.6% higher than that of AC-16. These findings support a coupled interfacial anchoring–chain mobility–viscoelastic damping mechanism and provide a materials-design basis for recycled rubber–asphalt mixtures with improved temperature- and frequency-dependent damping performance.