SBS polymer particle size impact on the characteristic time distribution of modified asphalt

Asphalt modified with a styrene–butadiene–styrene (SBS) block copolymer is used to improve the thermo-mechanical properties of conventional asphalt layers. In this study, we analyzed the distribution of characteristic times (λ) in SBS-modified asphalts containing different particle size distributions (i.e., by adjusting the production process), using rheological characterizations. These data were fitted to a multimodal Maxwell model using Mathematica Wolfram software. Specifically, the experimental data are master curves at 90 °C for Gʹ and Gʺ with respect to oscillation frequency. These rheological data demonstrate the viscoelastic nature of the SBS-modified asphalt, which is essential for evaluating its mechanical performance. It was found that the characteristic times (λ) and elastic moduli (G) representing the material's mechanical response, along with the results of the modified asphalts, could be described using six Maxwell systems.