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

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.