# Multi-Scale Synergistic Mechanism of Damping Performance in Crumb Rubber-Modified Asphalt

## TL;DR

This study explores how adding crumb rubber to asphalt improves damping performance, finding an optimal 20% content for best results.

## Contribution

The paper introduces a multi-scale framework linking rubber dispersion to damping performance in asphalt.

## Key findings

- Damping performance peaks at 20% crumb rubber content with significant loss modulus increases.
- Optimal rubber dispersion forms a 3D network, enhancing compatibility and damping efficiency.
- Ridge regression models confirm dispersion as the key factor in damping performance.

## Abstract

Utilizing waste tire crumb rubber to modify asphalt enhances the damping and noise reduction performance of pavements. This study employs a multi-scale approach to investigate the effect of crumb rubber content (5–25%) on the damping performance of crumb rubber-modified asphalt (CRMA). The results show that damping performance improves initially with increasing crumb rubber content, peaking at 20%, and then declines. At this optimal content, the loss modulus increases by 110% and 440% at 46 °C and 82 °C, respectively, compared to base asphalt, with enhanced damping efficiency and damping temperature stability. Fluorescence microscopy (FM) images and quantitative analysis reveal that, at 20%, the crumb rubber forms a moderately connected three-dimensional network. Molecular dynamics (MD) simulations indicate that, at this content, the solubility parameter of the CRMA system is closest to that of the base asphalt, and interfacial binding energy increases, suggesting optimal compatibility. Ridge regression models, with R2 values of 0.903 and 0.876 for the FM and MD scales, respectively, confirm that crumb rubber dispersion is the dominant factor governing damping performance, with moderate phase separation further enhancing performance. This study establishes a quantitative structure–property relationship, providing a framework for understanding the damping performance of rubber-modified asphalt pavements.