Performance Based Characterisation of Crumb Rubber Asphalt Modified using the Wet Process

ABSTRACT Current EU Directives have justified a fresh look at the use of crumb rubber from used tyres in asphalt for paving applications. A study was undertaken to investigate the influence of crumb rubber modification on binder and mixture performance-based properties. Crumb rubber from two origins, truck- and car-tyre was interacted with two penetration grade bitumens from different crude origins at various concentrations. Performance-related, rheological properties of the neat and rubber modified binders were evaluated at high and low temperatures. Based on their rheological performance, selected binders were incorporated in a Stone Mastic Asphalt mixture whose mechanical properties were evaluated. Emphasis was placed on the resistance of mixtures to permanent deformation, measured in the Wheel Tracking Test, and to fatigue cracking, measured in four-point bending fatigue. An attempt has been made to link performance-based binder and mix properties which are considered to correspond to one another.