Rheological properties of SEBS, EVA and EBA polymer modified bitumens

The rheological properties of various polymer modified bitumens were studie d. Three bitumens from two different sources were mixed with styrene-ethyle ne-butylene-styrene (SEBS), ethylene vinyl acetate (EVA) and ethylene butyl acrylate (EBA) copolymers at different polymer contents. The rheological p roperties of the modified binders were investigated by means of dynamic mec hanical analysis and creep test (bending beam rheometer). The results indic ated that polymer modification increased binder elastic responses and dynam ic moduli at intermediate and high temperatures, and reduced binder complex and stiffness moduli at low temperatures. Polymer modification also reduce d temperature susceptibility, glass transition temperature as well as limit ing stiffness temperature. The degree of the improvement generally increase d with polymer content, but varied with bitumen source/grade and polymer ty pe.