Environmental considerations in the new AASHTO pavement design guide: part 2, impacts on performance

This paper is a continuation of an earlier overview on the subject and presents the results of a sensitivity analysis that assessed the ability of the Mechanistic Empirical Pavement Design Guide (MEPDG) to portray the impact of temperature and moisture content on flexible pavements performance. The study used the most common asphalt concrete (HL3) and unbound materials (granular A and silty sand) used in Canada. Two binders (PG 52-34 and PG 58.28) and three moisture conditions (dry, wet and optimum) were chosen. Designs performed using level3 of analysis for unbound materials and level 1 for asphalt concrete showed the MEPDG is sensitive to binder performance grades as well as to climatic zones (cold vs. warm). However, the MEPDG showed limited sensitivity to the state of unbound materials where permanent deformation showed negligible changes between wet, dry and optimum conditions.Peer reviewed: YesNRC publication: Ye