Challenges associated with optimisation of blending, mixing and compaction temperatures for asphalt mixture modified with crumb rubber modifier (CRM)

The use of modified asphalt binders has become much more common over the past two decades. Many types of modifier have been used in paving asphalts to enhance the performance of asphalt pavements in a wide range of climates and loading conditions. Among various asphalts binder modifiers, the recycled crumb rubber has been used very successfully for many years. Generally in production of CRM binder, mixing and compaction temperature is determined by measuring of binder viscosity. The ordinary method used for viscosity measurement of unmodified binder leads to a very high Mixing and Compaction Temperature (MCT) for CRM binder. The aims of this paper are to identify, develop and give some recommendations on a reliable laboratory approach for blending of CRM with binder, as well as introducing appropriate laboratory test methods for optimisation of MCT of crumb rubber modified binder asphalt. © (2013) Trans Tech Publications, Switzerland.