Cracking of asphalt pavements and the development of specifications with rheological measurements Geoffrey M. Rowe 1, a , Mark J. Sharrock 1 1 Abatech, Blooming Glen, United States a growe@abatech.com Digital Object Identifier (DOI): dx.doi.org/10.14311/EE.2016.215 ABSTRACT The use of linear visco-elastic analysis methods for the characterization of asphalt binders has gained popularity since the wide introduction of rheometers in the early/mid 1990s. The use of the G*.sin(delta) parameter for fatigue cracking has been suggested as lacking the validation with field performance. However, this parameter at the intermediate temperature results in a required rheological index for the asphalt binder. The rheological index can be considered to be related to the requirement for grading at an intermediate temperature and can be expressed as a function of delta(t), the difference between the low temperature grade specified and the temperature used for the intermediate grade requirement. The R-value as developed by Christensen and Anderson is related to the relaxation spectrum and this is related to many of the parameters that correlate to cracking. For example French workers have suggested that the standard deviation of the relaxation spectra was an important consideration. Other concepts such as the Glover-Rowe parameter, visco-elastic transition temperature (VET) and/or the use of phase angle to understand fatigue can all be related to this R-value. This paper discusses the development of the specification around the concept of R-value and how this is controlled within the current specifications and the interrelationships between this parameter and various cracking studies. Keywords: Durability, Fatigue Cracking, Performance based standards, Rheology E&E Congress 2016 | 6th Eurasphalt & Eurobitume Congress | 1-3 June 2016 | Prague, Czech Republic