Linear Viscoelastic Behaviour of Polyacrylate Binders and Bitumen Blends

ABSTRACT This paper describes the linear viscoelastic (LVE) dynamic oscillatory properties of synthetic binders, as well as synthetic binder—bitumen blends, that have been synthesised from acrylic monomers by atom transfer radical polymerization (ATRP). The rheological properties of these binders have been determined using a dynamic shear rheometer (DSR) and frequency sweep tests. The results indicate that acrylic polymers, such as poly(ethyl acrylate) (PEA) and poly(methyl acrylate) (PMA), have rheological properties similar to that of 100/150 and 10/20 penetration grade bitumens, respectively. However, polyacrylates such as poly(butyl acrylate) (PBA) tend to be highly viscous at ambient temperatures and are therefore unsuitable as an asphalt mixture binder. The synthetic polymer binder—bitumen blends tended to be more compatible and stable when produced with a softer bitumen (70/100 pen or 100/150 pen) combined with a hard synthetic binder (PMA).