Fatigue Resistance of Unaged and Aged Bio-Bitumens: Time Sweep Test Versus Linear Amplitude Sweep Test

Fatigue resistance analysis in cyclic loading tests is vital to accurately estimate the fatigue life of asphalt materials in service. Although numerous fatigue test methods for bitumen using the dynamic shear rheometer (DSR) exist, direct comparisons of their results have been lacking. This study prepared eight different bitumens (unaged and aged, with and without bio-oil) and tested each with the two fatigue tests, namely, the linear amplitude sweep (LAS) test and the time sweep (TS) test. TS and LAS tests produced different rankings of fatigue performance. LAS test results presented low values related to the maximum shear stress. However, when both results were comparable with the same material integrity (0.5), the results showed a better comparison.