MECHANISTIC-EMPIRICAL DESIGN OF FLEXIBLE PAVEMENTS: A SENSITIVITY STUDY

Abstract

Pavement structural design is a daunting task. Traffic loading is a heterogeneous mix of vehicles, axle types and loads with distributions that vary daily and over the pavement design life. Pavement materials respond to these loads in complex ways influenced by stress state and magnitude, temperature, moisture, loading rate, and other factors. Environment exposure adds further complications. It should be no wonder the profession has resorted to largely empirical methods. Developments over recent decades offered an opportunity for more rational and rigorous pavement design procedures. The latest of these accomplishments is the development of the mechanistic-empirical pavement design procedure in NCHRP Project 1-37A. This study presents a comparison of flexible pavement designs between the 1993 AASHTO guide and the NCHRP 1-37A methodology and a sensitivity analysis of the NCHRP 1-37A's input parameters. Recommendations for future studies involving the application and implementation of the new mechanistic-empirical pavement design guide concludes the study.