Regulation Mechanisms and Evaluation System for the Damping Performance of Crumb Rubber-Modified Asphalt over the Wide Temperature Range

Utilizing waste tire crumb rubber to modify asphalt enhances the damping and noise reduction performance of pavements. This study systematically evaluated the damping performance of crumb rubber–modified asphalt over a wide temperature range. A high-temperature damping index based on the loss factor and a low-temperature energy dissipation ratio derived from the Burgers model were proposed for quantitative characterization. The results show that damping performance is primarily controlled by temperature and crumb rubber content, while particle size plays a secondary role. Increasing crumb rubber content markedly improves damping performance. When the crumb rubber content exceeds 20%, the damping temperature stability, peak loss factor, and its retention tend to level off, whereas the low-temperature enhancement diminishes when the content exceeds 25%. Accordingly, the robust combinations are 80-mesh (≈180 μm) with 20% content for high-temperature conditions and 80-mesh with 25% content for low-temperature conditions. Multivariate nonlinear regression models achieved high predictive accuracy (R2 = 0.927 and 0.985). Microscopic analyses indicate that crumb rubber increases constrained interfacial phases and system viscosity, and partial particle exposure at 20–25% further enhances interfacial friction and energy dissipation, consistent with the observed macroscopic damping behavior. These findings provide a theoretical basis for robust, noise-reducing pavements.