Page 185 - MODELING OF ASPHALT CONCRETE

CHAPTER 7

VEPCD Modeling of

Asphalt Concrete with

Growing Damage

Y. Richard Kim, Shane Underwood, Ghassan R. Chehab,
Jo S. Daniel, H. J. Lee, and T. Y. Yun

Abstract
This chapter presents the development of a viscoelastoplastic continuum damage
(VEPCD) model for the behavior of asphalt concrete in tension and compression. The
modeling strategy adopted is based on (1) the elastic-viscoelastic correspondence
principle, (2) continuum damage mechanics to account for the effect of microcracking
on the constitutive behavior, (3) a time- and stress-dependent viscoplastic model to
account for the plastic and viscoplastic behavior, and (4) the time-temperature
superposition (TTS) principle with growing damage to describe the effect of temperature
on the constitutive behavior. The resulting models are integrated by the strain
decomposition approach to form the VEPCD model.
The VEPCD model in tension is developed for four asphalt-aggregate mixtures with
three of the four mixtures modified by polymers. The model is shown to accurately
predict the material behavior in tension over a range of conditions different from those
used to characterize the model, including the results from the thermal strain restrained
specimen tensile (TSRST) tests at several different cooling rates. Finally, a brief discussion
on the VEPCD model in compression and the finite element implementation of the
model is given.

Introduction
Developing a realistic mathematical model of the mechanical behavior of asphalt concrete
with growing damage is a complicated problem. The complexity is attributed to the
viscoelastic hereditary effects of the binder, the complex nature of describing the damage

163
Copyright © 2009 by the American Society of Civil Engineers. Click here for terms of use.