Implementation of stress-dependent resilient modulus of asphalt-treated base for flexible pavement design

Abstract

Asphalt-treated base (ATB) is a widely used base course material in flexible pavements. Due to its lower binder content and lower quality granular material, resilient modulus (M_R) of ATB exhibits a stress dependent property. While most of the pavement analysis software used in the current routine design tasks is based on Burmister’s multi-layer elastic theory, in which the M_R is the primary fundamental material property, the software cannot truly deal with the stress-dependent M_R of paving material. In this study, M_R model in the Mechanistic Empirical Pavement Design Guide was adopted to accommodate the stress-dependent M_R of ATBs and the model was implemented in pavement mechanistic analyses through Abaqus finite element software and its user programmed subroutine. The comparison of critical pavement responses was made among pavements with three types of ATBs. Pavement responses obtained using the multi-layered elastic theory and based on resilient moduli recommended by Alaska Department of Transportation & Public Facilities, were also included for comparison.

Keywords:

• Asphalt-treated base
• stress dependent
• resilient modulus
• triaxial test
• pavement design