Polymer modified bitumen: Rheological properties and structural characterization

Polymer modified bitumen (PMB) is used extensively in thin asphalt surfacing and seals in order to improve specific performances. However, the performances of PMB are not easy to demonstrate with the conventional 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 deals with the characterization of linear copolymer styrene-butadiene-styrene (SBS) and SBS + polyphosphoric acid (PPA) modified bitumen by using conventional as well as advanced methods on bitumens at different ageing steps and temperature. Fundamental rheological tests, based on a state of the art dynamic shear rheometer in the temperature range from -30 degrees C to +160 degrees C and advanced H-1 magnetic resonance relaxometry 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 bitumen and the effect of the filler addition on the supra-molecular organization of the bituminous binder was also investigated. (C) 2015 Elsevier B.V. All rights reserved.