Linking the Fatigue Resistance of Nano-Modified Binders to Mixture Cracking

This study examined the correlation between binder-level fatigue properties and mixture-level cracking resistance in asphalt binders modified with five Nanomaterials (NMs): Nano-Silica (NS), Nano-Alumina (NA), and Nano-Titanium dioxide (NT) at 2%, 4%, and 6% as well as Nano-Zinc oxide (NZ) and Carbon Nanotubes (CNTs) at 1%, 2%, and 3%. Modified binders were subjected to Rolling Thin-Film Oven Test (RTFOT) and Pressure Aging Vessel (PAV) aging and tested at 25 °C using the Linear Amplitude Sweep (LAS) test to determine fatigue life (Nf) and the fatigue parameter G*.sin δ. The corresponding asphalt mixtures were evaluated using the IDEAL-CT test. The results indicated strong correlations between binder and mixture performance for NT, NZ, and NA, with NS exhibiting high correlation at lower strain levels, while CNT-modified binders showed weak relationships due to dispersion issues. Overall Desirability (OD) analysis identified 6% NT, 4% NA, 2% NS, 1% CNT, and 1% NZ as the optimal formulations. These findings offered practical guidance for selecting suitable NM types and dosages to improve pavement durability and optimize fatigue performance in asphalt mix design.