Rheology of conventional asphalt modified with SBS, Elvaloy and polyphosphoric acid

• PMAs were studied in small amplitude oscillatory shear and steady flows.
• Modifiers of asphalt blends were Elvaloy, PPA, SBS and sulfur.
• Addition of Elvaloy and PPA showed only a stiffening effect.
• Addition of SBS D1101 led to the creation of a 3D network.

The impacts of two different groups of polymers on the mechanical and rheological properties in a hard base asphalt were investigated. One group was modified with a reactive polymer, Elvaloy® 4170, with or without polyphosphoric acid (PPA). The other group used in this study was styrene butadiene styrene (SBS) D1101, either crosslinked with sulfur or not. The rheological properties of these materials were investigated by small-amplitude oscillations and steady-state shear viscosity. It was shown that the properties of a polymer modified asphalt blends beside depending on the type of polymer are strongly dependent on the presence of PPA and sulfur as it was clearly manifested in dynamic experiments. Steady state shear viscosity measured at 60 °C showed a possible chemical interaction between Elvaloy and PPA. The blends with SBS D1101 (at the same temperature) showed a more complicated behavior.