A more accurate fatigue characterization of GO-modified asphalt binder considering non-linear viscoelastic behaviour and UV exposure effects

The non-linear viscoelastic (NLVE) behaviour at high load levels is often neglected when characterizing the fatigue performance of asphalt materials, leading to a conservative or even underestimated assessment of the fatigue durability. The incremental stress sweep tests were conducted to define the threshold load amplitudes of the graphene oxide-modified asphalt binders (GO-MA) in the NLVE domain. The linear and non-linear dynamic shear modulus (|G*|LVE and |G*|NLVE) at fatigue test conditions were separately incorporated into the simplified viscoelastic continuum damage (S-VECD) model to rigorously quantify the fatigue life of asphalt binders. The damage evolution and the corresponding fatigue life of GO-MA binders in LVE-based and NLVE-based S-VECD models were analyzed comparatively. The outcomes manifested that GO nanoparticles could enhance the fatigue life of the asphalt binder. The comparison outcomes demonstrate an increase in fatigue life prediction for the base binder and GO-MA when both NLVE behavior and aging effects are taken into account.

Automated summary

The non-linear viscoelastic behavior of asphalt materials at high load levels is often disregarded, resulting in underestimated fatigue durability. This study conducted incremental stress sweep tests to determine the threshold load amplitudes of graphene oxide-modified asphalt binders in the non-linear viscoelastic domain. The fatigue life of the binders was quantified using a simplified viscoelastic continuum damage model, incorporating both linear and non-linear dynamic shear modulus. The results showed that the addition of graphene oxide nanoparticles improved the fatigue life of the asphalt binder, and considering non-linear viscoelastic behavior and aging effects increased the prediction accuracy of fatigue life for both the base binder and graphene oxide-modified asphalt binders.