In their quest to improve overall pavement performance and durability, pavement engineers in recent years developed and used innovative asphalt mixtures utilising engineered or modified asphalt binders. The technology of asphalt modification using refining processes has evolved in the past decade as a viable, effective alternative. Results of an extensive evaluation of several paving asphalt binders modified by refining processes are presented and discussed. The evaluation used testing and characterisation systems developed in the Strategic Highway Research Program (SHRP) and recent revisions of these systems as proposed in the NCHRP 9-10 project. Rheological, failure and ageing properties at temperatures that simulate pavement service were measured and analysed. Handling, constructability and performance characteristics of asphalt binders modified by refining processes are evaluated and compared with those of conventional materials and asphalt modified by different types of polymers. Comparative performance results on asphalt mixtures are presented to show the effect of the improvements in binder characteristics on mixture performance. Results on new binder test methods developed as part of NCHRP 9-10 are also presented comparing binder and mixture performance characteristics. For the covering abstract of this conference see ITRD number E211271.
Samenvatting