Validation of partial time-temperature superposition principle in thermorheologically complex asphalts

• Published in: Construction & building materials 2021-03, Vol.276, p.122224, Article 122224
• Main Authors: Hernandez-Fernandez, Noe, Ossa-Lopez, Alexandra
• Format: Article
• Language: English
• Subjects: Linear viscoelastic; Modified asphalt; Relaxation spectra; Thermorheological complexity; Time–temperature superposition
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2020.122224

•Six asphalts, one neat and five modified, were designed as a model material.•Black diagram successfully detected the thermorheological complexity on the modified asphalts.•The partial time–temperature superposition principle was introduced in this study.•The observed complexity was dependent on the type and concentration of the polymer.•Spectral functions were used to describe full viscoelastic properties of asphalts. This study aims to validate the applicability of the partial time–temperature superposition principle to simulate the behavior of thermorheologically complex modified asphalts. Six different asphalts were used to analyze this complexity using dynamic mechanical tests within the linear viscoelastic regime. The results showed that the complexity of polymer-modified asphalts is attributable to the formation of an entanglement network generated during the modification via physical and chemical processes based on the polymer type. It was also found that this network increased the modulus and decreased the viscous component at high temperatures, thereby improving the performance of modified asphalts. Despite the observed complex behavior, smooth and continuous master curves were obtained for viscoelastic properties different from the phase angle in frequency and time domains. For the phase angle and loss modulus master curves, the overall trend of the disjointed isothermal curves was simulated using a rheological model.