Rutting Resistance and Fatigue Behavior of Gilsonite-Modified Asphalt Binders

Fatigue damage and accumulation of permanent deformation or rutting are the two most prevalent distress mechanisms in flexible pavements. The aim of this study was to investigate rutting resistance and fatigue cracking in Gilsonite-modified asphalt binders. In this regard, the primary objective was to study the effect of Gilsonite content, binder type, and temperature on permanent deformation of asphalt binders. The Superpave rutting parameter (|G*|/sin) was calculated and the multiple stress creep and recovery (MSCR) test was performed for this purpose. The secondary objective was to evaluate the effect of Gilsonite content, binder type, and strain level on fatigue performance of asphalt binders. This was achieved using the linear amplitude sweep (LAS) test. According to the results, the addition of Gilsonite improved rutting resistance and fatigue properties of the asphalt binder. In addition, the results of evaluating the rutting parameter showed a good correlation between MSCR creep compliance (Jnr) and Superpave rutting parameter (|G*|/sin) in Gilsonite asphalt binders. The findings of this study indicate that Gilsonite-modified binders have better fatigue and rutting performance than the base binder, and Gilsonite is an economical choice and a suitable alternative for improving the asphalt binders' properties at high and medium temperature ranges.