Using rheology to study the effect of aging on fatigue performance of asphalt binder

The primary objective of this paper is to select a suitable index to characterise the change law of asphalt binder fatigue performance. Four asphalt binders were subjected to RTFOT and PAV. Frequency sweep (FS) test, Linear Amplitude Sweep (LAS) test, Pure Linear Amplitude Sweep (PLAS) test were performed on aged asphalt binder to obtain Glower-Rowe (G-R) parameter, fatigue life (Nf), fatigue resistance energy index (FREI). For the LAS test, three methods (Dissipated Energy(G*·sinδ), Complex Modulus (G*), Pseudo Strain Energy (PSE)) and four failure criteria (35% G*·sinδ initial, Peak Stress Strain, Peak Stress Pseudo-Strain, Max Storage PSE) were used to obtain the Nf. The results showed that the G-R parameter is more sensitive to aging. At high strain levels (>20%), the Nf obtained based on the 35% G*·sinδ initial decreased with increasing aging time, while the Nf obtained based on the rest of the failure criteria showed fluctuations. The FREI of the four asphalt binders showed the multi-stage linear decrease with increasing aging time and the decrease rate of each stage was significantly different, which was similar to the cracking path of conventional materials and is favourable for determining the location of the inflection points.