Contribution of MIST conditioning in evolution of structural parameters of asphalt mixes containing recycled asphalt pavement

Abstract

This study evaluates the effect of varying stress cycles of moisture induced stress tester (MIST) on structural parameters of asphalt mixes containing recycled asphalt pavement (RAP). Five levels of stress cycles were adopted viz. 1000, 2000, 3500, 5000 and 10,000. Bulk specific gravity tests (G_mb) were then conducted on asphalt mixes. The evaluated parameters included percent change in total air voids (pTAV), connected air voids (CAV), degree of saturation (S), percent density change (%DC) and swelling index (SI). The results indicated that pTAV, CAV,S, %DC, and SI increased with the increase in stress cycles. However, the inclusion of RAP was observed to decrease such parameters. ‘Good’ to ‘Excellent’ correlation existed between common parameter pTAV and CAV, S, %DC, SI. It is expected that the current study will assist in explaining how MIST conditioning affects the moisture damage susceptibility of asphalt mixes based on performance tests.

Keywords:

• Moisture-induced stress tester (MIST)
• stress cycles
• recycled asphalt pavement (RAP)
• air voids
• bulk specific gravity

Acknowledgement

Also, the authors gratefully acknowledge the financial support of the Department of Civil Engineering, IIT Bombay. We also express gratitude towards Mr. Bhagwan Shinde (Brihanmumbai Municipal Corporation, BMC) for assisting in supply of materials utilised in the current work.

Disclosure statement

No potential conflict of interest was reported by the author(s.

Additional information

Funding

The authors would like to thank Industrial Research and Consultancy Centre (IRCC), IIT Bombay, for providing financial support through project no. 17DST006, to purchase Moisture-Induced Stress Tester (MIST) utilised in the research work.