Thin asphalt pavement performance equation through direct computation of falling weight deflectometer-derived strains

Abstract

A fundamental aspect in a pavement management system is the evaluation of the pavement structural condition and its capability in supporting the designated traffic. The nondestructive technique of the falling weight deflectometer and the layered elastic model are commonly used to identify pavement structural condition. The approach in this article is mechanistic–empirical, with the intent to correlate the strain at the bottom of the asphalt layer with the number of coverages to failure. Strains were computed through mathematical approximation of the deflection basin measured at failure. The proposed asphalt criterion showed the same trend of the subgrade strain criterion developed in conjunction with the reformulation of the California bearing ratio (CBR)-Beta design criteria. The approach provided encouraging results when compared with the other analyses in the development of the CBR-Beta criteria. The database was from the full-scale flexible pavement testing at the US Army Engineer Research and Development Center in Vicksburg, MS, USA.

Keywords::

• falling weight deflectometer
• deflection basin approximation
• thin asphalt
• strain
• Gaussian curve

Acknowledgements

The author would like to thank Dr Walter Barker for the enlightening discussion on pavement performance, performance indicators and specifically the full-scale test section data that allowed the development of this article. Permission to publish was granted by Director, Geotechnical and Structures Laboratory of the US Army Engineer Research and Development Center.