The effect of tyre rubber grinding method on the rubber-asphalt binder properties

- Specific surface area of GTR depends on its grinding method.
- Morphology of GTR grains influences the properties of rubber-asphalt binder.
- Storage stability of rubber-asphalt binder also depends on its modification method.
- Addition of GTR to asphalt binder changes percentage of asphalt fractions.
- Added GTR effects molecular weight distribution of rubberized asphalt binder.

Rubber products, especially those used in the automotive industry, are responsible for a significant amount of waste, mainly in the form of worn tyres. One way to recycle tyres is to use them as an asphalt binder modifier. The properties of rubber-asphalt binders vary greatly depending on the morphology of the ground tyre rubber (GTR) grains and the type of tyre to be recycled (car/truck). The paper presents the results of research in the field of rubber-asphalt binders modified with two types of GTR (which differ in grain morphology) used in various amount and processed at different mixing devices. One GTR is obtained with the use of a standard knives granulator (standard granulation process - SGP), and the other by a special flat die pelleting press (flat-die granulation process - FDGP). It has been proved that GTR grinding method affects its specific surface area, thus the properties of rubber-asphalt binders.