Article
Fatigue endurance limit for HMA based on healing
Journal of the Association of Asphalt Paving Technologists
(2013)
Abstract
For many years the goal of the pavement community has been a long lasting flexible pavement. A knowledge of the stresses or strains below which damage does not occur or can be healed during unloading is required in order to design perpetual pavements. The strain or stress level below which the hot mix asphalt (HMA) would endure indefinite load repetitions and the pavement would not experience bottom-up fatigue cracking is known as the endurance limit, as applied to HMA and flexible pavement design. Determining the endurance limit for HMA under different conditions using laboratory beam fatigue tests is the purpose of this study. It is assumed by the approach used here that fatigue damage may not occur or can be healed during unloading, if stresses or strains are kept below a certain level. This approach is considered unique compared to previous studies that investigated these concept separately in that it relates healing to the endurance limit. According to the American Association of State Highway and Transportation Officials (AASHTO) T 321-03 test procedure as part of the National Cooperate Highway Research Program (NCHRP) 9-44A project, an extensive laboratory beam fatigue testing program covering a wide range of asphalt mixtures was conducted. The endurance limit was determined when no accumulated damage occurred indicating complete healing during the rest period after each load application. Depending on binder grade, binder content, air void, temperature and the rest period between load applications when 0.1 sec loading cycles are used, the endurance limit varied between 22 and 264 micro-strains (µs). Perpetual pavements can be designed that can sustain a large number of load applications if traffic volume and vehicle weights are controlled, using the results of this study.
Keywords
- Durability tests; Fatigue cracking; Fatigue limit; Flexible pavements; Hot mix asphalt; Perpetual pavements; Stiffness
Disciplines
Publication Date
2013
Citation Information
Mena I Souliman, W. Zeiada, M. Mamlouk and K. Kaloush. "Fatigue endurance limit for HMA based on healing" Journal of the Association of Asphalt Paving Technologists Vol. 82 (2013) p. 503 - 531 Available at: http://works.bepress.com/mena-souliman/52/