THE EFFECT OF NETWORK FORMATION ON THE RHEOLOGICAL PROPERTIES OF SBR MODIFIED ASPHALT BINDERS

Styrene-butadiene rubber (SBR) was used to modify asphalt binders. The rheological and thermo-mechanical properties of tile binders were inv estigated using rotational viscometry, dynamic shear rheometry, and th ermal mechanical analysis. The optimum SBR content and mixing procedur e mere determined based on the rheological properties of the asphalt/S BR blends. The addition of 3-5% (w/w) SBR resulted in enhanced high te mperature performance of the binders. The SBR. progresses from a dispe rsed polymer to local networks to a global network with increasing SBR content. This phenomenon is exhibited in rheological properties such as complex modulus and melt viscosity. It is also verified visually by using a Laser Scanning Confocal Microscope. Because of tills network formation, the binders showed a large increase in the complex modulus which indicates resistance to rutting.