Rutting characteristics evaluation and prediction model development for warm mix asphalt

ABSTRACT

The warm mix asphalt (WMA) technology has brought environmental sustainability into the pavement industry with its preparation at lower production temperatures than hot mix asphalt (HMA). Nevertheless, it has also raised concerns regarding the mixture’s resistance to permanent deformation as a result of its reduced aging during production. This study examines the effects of warm mix modification on the rutting potential of bituminous mixes. Two modifiers were used for WMA preparation – polyethylene wax (PEW) and waste cooking oil (WCO). Binder rutting properties were evaluated using the multiple stress creep recovery (MSCR) test. Subsequently, WMA mixtures were prepared at adequate production temperatures, and then their rutting characteristics were evaluated using the Cooper wheel tracker device. The study concluded that introducing warm mix modifiers in small amounts, approximately 1–2% by weight of bitumen, results in rutting characteristics comparable to virgin bituminous mix, whereas the characteristics deteriorate at higher modifier contents. Furthermore, a rutting prediction model based on the Weibull failure rate function (WFRF) was developed. A strong correlation was found between the measured wheel tracking data and the prediction model in all mixtures. PEW was discovered to be a superior warm mix modifier to WCO in terms of rutting resistance.

KEYWORDS:

• Warm mix
• rutting resistance
• MSCR
• wheel tracking test
• Weibull failure rate function
• rut prediction model

Acknowledgements

The authors would like to express their gratitude to Dr. Sumit Kumar Singh of Anton Paar India Pvt. Ltd., Kolkata, for his kind assistance and cooperation with the multiple stress creep recovery (MSCR) testing.

Disclosure statement

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