Incremental Repeated Load Permanent Deformation Testing of Asphalt Mixtures

The provisional test protocol for the Repeated Load Permanent Deformation (RLPD) test known as flow number test (AASHTO TP 79-09) does not specify temperature and stress level. For this reason, different laboratories conduct the test at different temperatures and stress levels, from which the results could not be easily compared. In addition, the flow number is highly dependent on stress level and test temperature which can make the testing time and results unpredictable. In this paper, a new incremental RLPD test procedure is proposed, in which the sample is subjected to multiple stresses in several increments. Instead of a test being continued at one stress level until flow, it is terminated during the secondary stage and restarted at a new stress level. This provides the opportunity to repeat the test on the same sample at several temperatures and stress levels as long as the sample remains in the secondary stage of deformation. The Minimum Strain Rate (MSR) values at the end of each increment are the properties of the incremental RLPD test. From the RLPD test results of three different mixtures at various temperatures and stress levels, it was found that the effect of temperature and deviatoric stress on MSR is interchangeable. A variable total particulate (TP) that is the product of temperature and stress were defined to correlate to MSR. A master curve of MSR vs. TP was then used to characterize high temperature performance of the asphalt mixtures tested in this study at any stress level and test temperature.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK50 Characteristics of Asphalt Paving Mixtures to Meet Structural Requirements
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Azari, Haleh
  • Mohseni, Alaeddin
• Conference:
  • Transportation Research Board 91st Annual Meeting
  • Location: Washington DC, United States
  • Date: 2012-1-22 to 2012-1-26
• Date: 2012

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: TRB 91st Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Asphalt mixtures; Deformation; Load tests; Repeated loads; Temperature endurance tests
• Uncontrolled Terms: Permanent deformation; Strain rate; Stress level
• Subject Areas: Highways; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01373446
• Record Type: Publication
• Report/Paper Numbers: 12-4381
• Files: TRIS, TRB
• Created Date: Jun 22 2012 1:13PM