Rheological and Aging Characteristics of Polymer-Modified Asphalt with Addition of Sulfur ^†

The polymer modification of asphalt binders was first introduced in Europe in the 1980s and has gained use, as lower-quality asphalt binders did not perform well under increasingly heavier traffic loading on pavements. The influence of chemical cross-linkers such as sulfur on the rheological, morphological, and aging characteristics of the polymer-modified asphalt (PMA) binder has been experimentally examined. The PMAs were prepared, blending different sulfur contents (0.03, 0.1, 0.3, and 0.5% by wt. of binder) with a neat binder. The samples were aged by a rolling thin film oven (RTFO) and a pressure aging vessel (PAV) and examined through rheologic investigations. Using models, including master curves, the Glover–Rowe parameter, and aging indexes, the effect of the aging resistance of the asphalt binder modified with sulfur was analyzed. The results indicate that adding sulfur up to 0.3% improved the performance grade range, elasticity, low-temperature cracking resistance, and rutting resistance of the PMA. Additionally, the introduction of sulfur improved the aging resistance of the PMA.