Asphalt pavement cracking: analysis of extraordinary life cycle variability in eastern and northeastern Ontario

Abstract

This paper documents an investigation of the performance of 20 pavement contracts in eastern and northeastern Ontario, Canada. Eleven of these pavements showed little or no distress after 7–15 years in service. The remaining nine, aged between 7 and 13 years, all cracked prematurely and excessively. Creep testing of the recovered asphalt cements, according to an extended bending beam rheometer protocol, revealed that the long-life pavements were made with materials that suffered little from reversible ageing mechanisms during cold conditioning. Ductile failure testing in a double-edge notched tension test at 15°C revealed equally significant differentiation, with the superior performing materials possessing considerably higher strain tolerances. The newly developed methods were able to explain vast performance differences with 95% accuracy. This study further validates Ontario's interest in an improved asphalt cement grading approach and provides evidence that thin pavements can have long lives, provided the asphalt cement is selected properly.

Keywords:

• long-life pavements
• asphalt binder grading
• performance prediction
• low-temperature cracking
• fatigue cracking
• reversible ageing
• critical crack opening displacement

Acknowledgements

The authors wish to thank Imperial Oil of Canada, the Ministry of Transportation of Ontario and the Natural Sciences and Engineering Research Council of Canada for their continuing financial support. Appreciation is expressed to Maureen Garvie for proofreading of this manuscript and to Chris Belanger, Darren Waters, Adrian Sgoifo, Kevin Houlihan and Paul Togunde for their assistance with the collection of contract information and experimental data as reported in this manuscript.

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.