Sensitivity of the Pavement ME Design Software Predicted Distresses in Flexible Pavements to Granular Base Materials

Abstract
Granular base materials constitute a considerable portion of flexible pavement structures. In empirical design methods, 1 mm of asphalt concrete (AC) thickness generally equates to 3-4 mm of granular base thickness with no concern related to pavement performance. Experience has also shown that an increased base layer thickness and a stiffer base material can significantly enhance the performance of flexible pavements. However, there are concerns that the newest pavement design and analysis tool, named the AASHTOWare Pavement ME Design (PMED) software, is not yet able to consider the effect of unbound materials properly.    


Between May and November 2021, Transportation Association of Canada (TAC) ME Pavement Design Subcommittee completed five sets of design trials to assess the sensitivity of the PMED software predicted distresses to the physical and mechanical properties of granular base materials. The design trials included: i) six different granular base specifications with varying physical and mechanical properties with no subbase layer, ii) six different granular base specifications with varying physical and mechanical properties with a subbase layer, iii) six different sources of granular base materials with varying stiffness with two different gradations, iv) three different granular base gradations with constant stiffness value, and v) varying base layer thickness for two different materials. The results have shown negligible to excessive sensitivity of the predicted distresses to the variation of base material stiffness, gradations and thickness with some inconsistencies.

Author

Ahammed, M. Alauddin
Roby, Julie
Karim, Mohammad
Esfandiarpour, Sam

Titre de la séance

Innovations in Pavement Management, Engineering and Technologies

Catégorie

Chaussées

Year

2022

Format

Paper

File

 


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