A more accurate fatigue characterization of GO-modified asphalt binder considering non-linear viscoelastic behaviour and UV exposure effects. (March 2023) - An, Xin
Highlights: ·Nonlinear viscoelastic behavior and UV exposure effects were taken into account in the fatigue characterization model of asphalt binders. ·The non-linear dynamic modulus ( |G*|NLVE ) was incorporated into the damage model to rigorously quantify the fatigue life of asphalt binders. ·Compared to the LVE-model, the NLVE-model predicts more accurate fatigue life and durability performance of the GO-MA binders. ·The experimental findings proved that GO can prolong the fatigue life of asphalt binders. ·The predicted fatigue life of the asphalt binder increased when NLVE behavior and aging effects were incorporated into the prediction model. Abstract: 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.