Overview of environmental considerations in AASHTO pavement design guides

This paper presents an overview of the effects of environmental factors, namely moisture and temperature, on the material properties of flexible pavement road structure considered in the design guides of AASHTO. It considers the historical development of AASHTO design guides with new design guides. The study showed the shift in emphasis from total reliance on an empirical method to a combination of mechanistic and empirical methods in the new design guide. Further, moisture and temperature were indirectly considered in the current guide, whereas these parameters are accounted for in the new design guide through the resilient modulus and the complex modulus. The sensitivity analyses of environmental consideration using the new design guide software are presented in this paper