Time–temperature superposition in rheology and ductile failure of asphalt binders

Abstract

This paper documents and discusses an investigation into the time–temperature superposition principle as it relates to ductile failure in asphalt. Seven binders of approximately the same low and intermediate temperature and varying high temperature Superpave^® grades were tested in a dynamic shear rheometer (DSR) and double-edge-notched tension test to determine their rheological and failure energy master curves. Master curves typically permit the prediction of rheological properties at very long or short timescales from measurements at higher or lower test temperatures over more accessible testing timescales. It has been suggested in the Strategic Highway Research Program final report A-369 that rheological shift factors obtained from a DSR experiment can be used to predict failure master curves from experimentally accessible data at various temperatures. The findings of this study suggest that this substitution is not generally accurate. For straight asphalt binders the difference can be relatively small but for more highly modified materials serious errors would be introduced.

Keywords:

• asphalt binder grading
• fatigue cracking
• time–temperature superposition
• master curve generation
• essential and plastic works of fracture

Acknowledgements

The authors wish to thank Imperial Oil of Canada, the Ministry of Transportation of Ontario, the Innovations Deserving Exploratory Analysis (IDEA) programme as administered by the National Cooperative Highway Research Programme and the Natural Sciences and Engineering Council of Canada for their financial support.

Liaisons for the Ministry of Transportation of Ontario were Pamela Marks and Kai Tam, and for the NCHRP-IDEA programme, Edward Harrigan and Inam Jawed. Further, guidance and support were kindly provided by Lyle Moran of Imperial Oil of Canada.

Finally, appreciation is expressed to Maureen Garvie for the proof-reading of this manuscript and to Kai Tam for his assistance with the crack survey on Highway 655.

Disclaimer. None of the sponsoring agencies necessarily concur with, endorse, or agree to adopt the findings, conclusions, or recommendations either inferred or expressly stated in subject data developed in this study.

Notes

^1. Institute of Macromolecular Chemistry, ‘P. Poni’, Iasi, Romania.

Additional information

Notes on contributors

Adrian Andriescu

1. 1. Institute of Macromolecular Chemistry, ‘P. Poni’, Iasi, Romania.