Abstract
Accurate analysis of fatigue resistance through cyclic loading tests is crucial for precisely estimating the fatigue life of asphalt materials in service. Despite the availability of some fatigue test methods for bitumen using the dynamic shear rheometer, direct comparisons of their results are rare. In this study, twelve different bitumen (including unaged and aged, with and without bio-oil) were prepared and tested using two testing protocols: the linear amplitude sweep (LAS) test and the time sweep (TS) test. Results from TS tests and LAS tests exhibited discrepancies in fatigue performance. However, the results demonstrated improved comparability upon modifying the LAS calculation procedure to consider variable values for material integrity. The suggested modification involved fixing the material integrity for LAS calculations at the same level used in TS tests (C = 0.5). Although this adjustment may still lead to underestimating fatigue resistance, prioritizing safety in practical terms favors using LAS tests. It is concluded that the LAS test is a valuable indicator for evaluating the fatigue resistance of both aged and unaged bio-bitumen, particularly in scenarios where time efficiency is paramount.