Using different performance measures for the sustainability assessment of asphalt mixtures: case of warm mix asphalt in a hot climate

Abstract

The study presents a framework for assessing the sustainability of different types of asphalt materials and technologies. The framework is demonstrated through a case study for evaluating the sustainability of warm mix asphalt (WMA) mixtures in hot climatic conditions. While various life-cycle assessment (LCA) tools and methodologies have been used for sustainability assessment of WMA from the material production phase to the construction phase, most neglect the maintenance, rehabilitation and end of life phases, based on the assumption that the performance of WMA is similar to that of hot mix asphalt (HMA). This study examines asphalt mix properties and performance indices, and studies their impact on maintenance and rehabilitation schedules when incorporated in a pavement structure, and subsequently life-cycle environmental and economic costs. The study concludes that the assessment outcomes of the LCA and life-cycle cost analysis are heavily affected by the performance measure used to predict the maintenance and rehabilitation schedule or change in service life. For the conditions assumed in the study, WMA mixes yield more favourable environmental and economic results compared to control HMA mixes with unmodified binder.

Keywords:

• life-cycle assessment
• warm mix asphalt
• life-cycle cost analysis
• sustainability assessment
• performance assessment
• asphalt pavement

Acknowledgements

The statements made herein are solely the responsibility of the authors. The authors acknowledge the support of the manager and staff of the Civil and Environmental Engineering Laboratory at the American University of Beirut.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Qatar National Research Fund [NPRP 5-506-2-203], a member of Qatar Foundation.