Bitumen (BIT) has been used in most road applications for many decades as the binder for asphalt. The most common distresses, directly associated to binder phase in road are permanent deformation known as rutting and thermal cracking. This has resulted in the need to enhance the properties of existing bitumen material. In order to produce BIT with improved properties polymers are used. It is known that the modified binders vary significantly in their sensitivity to traffic speed, to traffic volume, and to stress or strain level that varies according to pavement structure which indicated the importance of rheological properties investigations. Investigation of rheological properties of polymer modified bitumens (PmBs) with various polymers as a potential modifiers as well as bitumens gives the possibility of PmBs characterization and evaluation as binder.
The research program in the field of road construction, SHRP (Strategic Highway Research Program) includes the investigation of rheological properties at traffic frequency and temperature which gives insight into a permanent deformation known as rutting and the effect of thermooxidative aging.
In this paper as bitumen modifiers following polymers are used: styrene –butadiene-styrene (SBS) block copolymers, linear and radial structure, plastomer ethylene- vinyl acetate (EVA) and reactive polymer ethylene glycidil acrylate (EGA). Resistance to permanent deformation what includes the investigations of rheological properties of BIT and PmB are performed with dynamic shear rheometer (DSR) in broad temperature range at traffic frequency before and after ageing. The ageing of the investigated materials, termooxidative stability, is determined by Rolling Thin Fim Oven Test (RTFOT).
Polymer modified bitumens are less sensitive to temperature and traffic speed than bitumen. They have a higher critical temperature i.e. resistance to permanent deformation. The critical temperature depends on polymer type and content.

PmB, DSR, rheological properties, permanent deformation, SHRP