Steps towards the detection of reclaimed asphalt pavement in superpave mixtures

Abstract

For quality control and quality assurance purposes, it would be desirable to quantify the amount of reclaimed asphalt pavement (RAP) already incorporated in a recycled hot mixture. If RAP is incorporated in higher amounts than approved, without a proper design, it can affect the integrity of the mix and can compromise the performance and lifespan of the pavement. Twelve different laboratory prepared asphalt mixtures with variable virgin asphalt binder grade and RAP content were subjected to multiple testing protocols to determine which variables were most significant for rutting, thermal cracking and mechanical response. Statistical analyses demonstrated that the performance of recycled hot mixtures is the result of the combined effect of the RAP content and the binder grade. It was observed that the quantity of RAP could be strongly related to the results of the indirect tensile strength, flow number, and fracture energy.

Keywords:

• reclaimed asphalt pavement
• Superpave recycled hot mixtures
• wearing course
• laboratory performance
• detection of RAP

Acknowledgements

A sincere acknowledgment for the contributions of Vince Aurilio from DBA Engineering Ltd., Alexander “Sandy” Brown from OHMPA, Pamela Marks and Seyed Tabib from MTO, and Fernando Magisano from K.J. Beamish Construction Co. Also, the authors are also thankful for the in-kind donations from Capital Paving Limited., McAsphalt Industries, Canadian Asphalt, Coco Paving, Bitumar and Golder Associates.

Additional information

Funding

This research was sponsored by the Ministry of Transportation Ontario (MTO), the Ontario Asphalt Pavement Council (OAPC), and the Natural Science and Engineering Research Council of Canada (NSERC); their support is greatly appreciated.