Mixture-based rheological evaluation tool for cracking in asphalt pavements

Abstract

Cracking is a major distress that limits the durability of asphalt pavements. Various fatigue and fracture-based tests and analyses can be used to assess cracking resistance of asphalt mixtures in order to design more economical and durable mixtures. This mixture cracking resistance is affected by the rheological properties of the asphalt binder, both stiffness and relaxation ability as indicated by measured dynamic modulus and phase angle, respectively. One significant breakthrough involves the use of binder Black space (shear modulus versus phase angle) and the Glover–Rowe (G-R) parameter that is a function of these two rheological properties as an indication of cracking resistance. However, binder characterisation is not adequate to fully represent mixture performance and therefore there is a need for a mixture-based evaluation tool. The objectives of this study were to: (1) investigate the applicability of a representative temperature and frequency combination for mixture-based Black space evaluation; (2) evaluate the ability of mixture Black space to track the effect of aging and rejuvenation (when recycling agents are used with recycled materials); (3) explore the use of a mixture-based G-R parameter (G-R_m) for cracking resistance evaluation and (4) investigate a possible correlation between G-R_m and Flexibility Index (FI) from a semi-circular bending (SCB) test. Test results indicate a reliable temperature–frequency combination for G-R_m, which was sensitive to aging, recycled materials content, binder performance grade and recycling agent dose. Test results also indicate a good correlation between the G-R_m parameter and the FI.

Keywords:

• aging
• Black space
• cracking
• flexibility index
• Glover–Rowe parameter
• recycling agents

Acknowledgements

The authors would like to acknowledge the National Cooperative Highway Research Program (NCHRP) project 9-58 and New Hampshire Department of Transportation (NHDOT) for sponsoring portions of this study. The authors acknowledge Lorena Garcia Cucalon and Arif Chowdhury (from Texas A&M Transportation Institute), Stacy Glidden and John Bartoszek (from Payne and Dolan, Inc.), and Dario Batioja-Alvarez, Alberto Albejjani, and Mateo Carvajal (from the University of Nevada, Reno) for their efforts in field activities coordination and materials procurement. The authors also acknowledge Thomas Henz, Geoffrey Giannone and Kyle Doe of the Texas A&M Transportation Institute for their efforts and contributions in the laboratory.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Fawaz Kaseer http://orcid.org/0000-0002-9443-4429

Jo E. Sias http://orcid.org/0000-0001-5284-0392

Amy Epps Martin http://orcid.org/0000-0001-7207-5368