AASHTO Issues Revised Pavement Design Guide
The American Association of State Highway and Transportation Officials has released a new publication: Mechanistic-Empirical Pavement Design Guide: A Manual of Practice, 3rd Edition.
This revised manual provides an overview of the methodology termed mechanistic-empirical or “M-E” pavement design.
Based on engineering mechanics that have been validated through extensive road test performance data, the manual references AASHTOWare Pavement ME Design and M-E Pavement – crafted as part of the AASHTO’s software development program.
Major revisions in the third edition of this manual include:
- New fracture mechanics-based model for reflective cracking in asphalt overlays over flexible, semi-rigid and rigid pavements.
- New mechanistic-empirical model for short jointed plain concrete pavement or SJPCP overlays of flexible pavements.
- New flexible and semi-rigid pavement global calibration coefficients.
- Addition of non-structural preventative maintenance treatment consideration for flexible and rigid pavements.
- Addition of five “level 3” default distributions for normalized axle load spectra, known as NALS.
- Updated climate discussion for Modern Era Retrospective Reanalysis and North American Regional Reanalysis data.
- Incorporation of crack load transfer efficiency or LTE for flexible pavements;
- Expanded guidance for creep compliance and indirect tensile strength inputs for asphalt wearing surface layers.