Characterization and prediction of asphalt binder fatigue life using the time sweep test

Accurately predicting asphalt binder fatigue life is essential for improving pavement durability design. However, existing Linear Amplitude Sweep (LAS) test predictions still exhibit considerable deviations from the measured fatigue life obtained from the Time Sweep (TS) test. The LAS test has been widely adopted as an accelerated alternative to the TS test for rapid fatigue evaluation. Nevertheless, studies have indicated significant differences between the predictions from the older AASHTO TP 101–14 and the newer AASHTO T 391–20 standards, while systematic comparisons with actual TS measurements remain limited. To address this gap, this study selected two neat asphalt binders and three modified variants, including styrene-butadiene-styrene (SBS)-modified, natural rock asphalt-modified, and dioctyl phthalate-modified, and subjected them to three aging levels: one-cycle Rolling Thin Film Oven, one-cycle Pressure Aging Vessel (1PAV), and two-cycle Pressure Aging Vessel. The fatigue life predictions from the two LAS standards were systematically compared against TS measurements. Results demonstrate that the TP 101–14 standard systematically underestimates fatigue life and is only consistent with TS rankings when material performance differences are substantial. The T 391–20 standard significantly overestimates fatigue life at lower strain levels, though it provides more stable performance ranking across specimens. A new prediction method was then proposed, which calibrates the S‑VECD model parameters using TS test data at a relatively high strain level. This method replaces the strain-amplitude damage accumulation mode of the LAS test with the constant-strain damage accumulation mode of the TS test, and modifies the calculation formulas for the D f and α parameters. The proposed method achieves excellent consistency between predicted and measured fatigue lives across all specimens (R² > 0.95). Additionally, validation using the G R parameter shows that the predicted fatigue life exhibits a strong linear correlation with the energy dissipation rate (R² > 0.94). This study predicts asphalt binder fatigue life based on time sweep test data within the calculation framework of the T 391–20 standard, achieving a favorable balance between testing efficiency and prediction accuracy with good stability.