Polymer modified bitumen: Rheological properties and structural characterization

Polymer modified bitumen (PMB) is used extensively in thin asphalt surfacing and seals in order toimprove specific performances. However, the performances of PMB are not easy to demonstrate with theconventional methods, such as penetration test, softening point etc. In order to a better evaluation, different characterization methods are needed rather then ordinary empirical rheological tests. This work dealswith the characterization of linear copolymer styrene–butadiene–styrene (SBS) and SBS + polyphosphoricacid (PPA) modified bitumen by using conventional as well as advanced methods on bitumens at differ-ent ageing steps and temperature. Fundamental rheological tests, based on a state of the art dynamicshear rheometer in the temperature range from −30◦C to +160◦C and advanced1H magnetic resonancerelaxometry analysis to evaluate the effect of modifiers on the bitumen structure, were used. Moreover,morphological analysis by scanning electron microscope (SEM) was performed on neat and modified bitu-men and the effect of the filler addition on the supra-molecular organization of the bituminous binderwas also investigated.