Thermal cracking in cold regions’ asphalt mixtures prepared using high polymer modified binders and softening agents

ABSTRACT

This study was conducted to assess high polymer modified asphalt binders including a corn oil-based softening agent (SA) and their impact on the cracking performance of mixtures in cold regions. Styrene–Butadiene-Styrene (SBS) polymer modifier, corn-oil-based softening agent, and Performance Grade 52–34 binder were proportioned at various dosages to prepare modified binders. The mixtures were aged according to three loose mix aging procedures (short-term, long-term, and extended long-term). It was found that the SBS and corn-oil combination improved both the high and low continuous grade along with percent recovery, and reduced fatigue cracking potentiality based on a reduced negative ΔT_c at the binder level. In addition, at the mixture level, an increase in the Disc-shaped Compact Test (DCT) fracture energy was observed at low temperatures; also an increase in cracking temperature due to thermal stress from Thermal Stress Restrained Specimen Test (TSRST) was observed, indicating better cracking resistance. Regardless of aging, the flexural stress from the beam fatigue test also decreased, indicating higher resistance to fatigue cracking at intermediate temperatures. The study suggests that the balanced application of SBS and corn-oil can lead to the optimum improvement in low temperature cracking performance of the evaluated asphalt mixtures.

KEYWORDS:

• Highly elastic binders
• softening agents
• corn oil
• asphalt mix performance
• low-temperature cracking
• and aging effects

Acknowledgements

The experiments described and the resulting data presented herein, unless otherwise noted, were funded under PE 0602784A, Project T53 ‘Military Engineering Applied Research’, Task 08 under Contract W913E518C0008, managed by the US Army Engineer Research and Development Center (ERDC). The work described in this paper was conducted at Rowan University’s Center for Research and Education in Advanced Transportation Engineering Systems (CREATES), Mullica Hill, NJ. Thanks to graduate student Basel al Badr for helping to prepare the samples. Special thanks are also due to Mr. Keith Sterling for providing the aggregates was used in this study, Mr. Alex McCurdy for supplying the corn oil softening agent, Mr. Bob Klutz for providing comments and the SBS modifier, and Ms. Paula Marc for supplying the PG52-34 binder. The authors confirm contribution to the paper as follows: study conception and design: Sk Faisal Kabir, Ayman Ali, Christopher J. Decarlo, Mohamed Elshaer and Yusuf Mehta; data collection, analysis, and interpretation of results: Sk Faisal Kabir, Caitlin Purdy and Ayman Ali; draft manuscript preparation: Sk Faisal Kabir, Ayman Ali, Caitlin Purdy and Yusuf Mehta. All authors reviewed the results and approved the final version of the manuscript.

Disclosure statement

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

Data availability statement

All data, models, and code generated or used during the study appear in the submitted article.

Additional information

Funding

This work was supported by Cold Regions Research and Engineering Laboratory: [Grant Number W913E518C0008].