Characterizing the Temperature Effects on Rutting and Fatigue Properties of Asphalt Binders Based on Time-Temperature Superposition Principle

The objective of this article is to investigate the effects of temperature on rutting and fatigue cracking resistance of asphalt binders based on the time-temperature superposition principle (TTSP). In this study, the TTSP approach was employed to interpret the results of multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests for both neat and styrene-butadiene-styrene (SBS)–modified asphalt binders. The higher stress level of 3.2 kPa in the standard MSCR test procedure was extended to 10 and 15 kPa to verify the stress sensitivity of the nonrecoverable compliance (J_nr). A loading duration of 5 minutes in the standard LAS test was extended to 10 and 15 minutes to develop the fatigue failure criterion at different conditions. The results demonstrate that the time-strain curves of the neat binder during the MSCR tests under different temperatures can be unified into a single strain master curve using the TTSP shift factors, based on which the predictive J_nr showed good agreement with the measured values. This TTSP-based analysis approach does not work well for the MSCR results of the SBS-modified binder at high temperatures. However, the fatigue failure criterion determined from the LAS tests under different temperatures was verified to be successfully constructed into a single failure criterion according to the TTSP approach for both the neat and SBS-modified binders. Therefore, only an additional caution is raised for the TTS-based analysis on rutting resistance of the modified binder in a high temperature range.