Effects of Aging Protocols on the Discrimination Potential of a Cracking Test in Asphalt Mixtures

Performance-related testing—including cracking and rutting—as a feature of the asphalt mixture design process has garnered significant attention in recent years. One salient question related to implementation of mix-design performance testing is the amount and protocol for “aging” the mixture in the laboratory, ostensibly to “mimic” aging which occurs on in-service pavements. Many laboratory aging protocols have been proposed; some protocols are not practical for mix design (and potentially for QC/QA) due to, among other considerations, the excessive time spent in the oven. For many laboratory “performance” tests, prediction of actual field performance is less desirable than the ability to (relatively) rank or evaluate the cracking resistance of various laboratory mixes. This paper describes the effects of different aging protocols on the discrimination potential of the Illinois semi-circular bending test (SCB-IL/I-FIT). Three highways in Arkansas, for which field performance has been monitored since construction, are included in the study. Three long-term oven aging (LTOA) protocols are applied: NCHRP Report 871, NCAT “top-down cracking” program, and AASHTO R 30 for mechanical testing; one short-term oven aging (STOA) protocol, AASHTO R 30 for volumetric analysis, is also included. The discrimination potential resulting from the combination of each aging protocol and the cracking test is evaluated, both statistically and with an element of judgment regarding items such as practicality. Preliminary results indicate that all long-term aging protocols lead to comparable laboratory cracking performance regardless of observed field performance; this potentially allows the selection of an aging protocol based on practicality and convenience for use in routine practice.

Language

  • English

Media Info

  • Media Type: Web
  • Pagination: pp 51- 61
  • Monograph Title: Airfield and Highway Pavements 2019: Testing and Characterization of Pavement Materials

Subject/Index Terms

Filing Info

  • Accession Number: 01728544
  • Record Type: Publication
  • ISBN: 9780784482469
  • Files: TRIS, ASCE
  • Created Date: Jul 18 2019 3:02PM