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Modeling of Asphalt Concr ete 7

model for the compression behavior of asphalt concrete; and (c) a simple performance test
to identify the rutting potential of mixtures during the design process, based on the
measurement of fundamental engineering responses and properties. It is noted that the
VEPCD model adopted in this chapter employs the same principles as found in Chap. 7
in Part 3, except that the HiSS-Perzyna model is used to describe the viscoplastic strain of
asphalt concrete instead of the strain-hardening model used in Chap. 7.

Part 5—Models for Fatigue Cracking and Moisture Damage
The detrimental effects of moisture and fatigue damage are discussed in Part 5 of this book.
Chapter 12 focuses primarily on the fatigue damage mechanisms with a particular interest
in the acceleration of such damage growth with additional moisture damage. Surface
energy principles, fracture mechanics, and continuum damage mechanics are utilized for
this argument. In Chap. 13 more attention is given to the moisture damage phenomenon. A
review of current procedures for moisture damage assessment is given as a precursor to
more advanced, objective techniques for the assessment of moisture damage.

Part 6—Models for Low-Temperature Cracking
Part 6 of this book discusses thermal cracking of asphalt concrete pavements. Mechanisms and
events leading to thermal cracking are discussed in detail in Chaps. 14 and 15. Chapter 14
presents the TCMODEL, which has been implemented into the NCHRP 1-37A MEPDG
to predict thermal cracking performance. The second chapter, Chap. 15, casts the phenomenon
in the light of fracture mechanics and presents experimental results of multiscale modeling
efforts encompassing binder, mastic, and mixture modeling.

Concluding Remarks
This book attempts to document models of asphalt concrete and should be regarded as an
evolving document, as some of the models are still being refined and improved. It also may
be noted that this book focuses mostly on continuum models in order to maintain a reasonable
length. Significant advancements in micromechanical modeling of asphalt concrete have
also been made. Nonetheless, this book should provide a fair presentation and sufficient
review of mechanistic models that are currently available at the time of publication.

References

Kim, Y. R., H. J. Lee, Y. Kim, and D. N. Little, Mechanistic Evaluation of Fatigue Damage
Growth and Healing of Asphalt Concrete: Laboratory and Field Experiments,
Proceedings of the Eighth International Conference on Asphalt Pavements, International
Society for Asphalt Pavements, University of Washington, Seattle, Washington, 1997,
pp. 1089–1107.
NCHRP 1-37A Research Team, “Guide for Mechanistic-Empirical Design of New and
Rehabilitated Pavement Structures,” Final Report, NCHRP 1-37A, ARA, Inc. and
ERES Consultants Division, 2004.
Park, S. W., Y. R. Kim, and R. A. Schapery, “A Viscoelastic Continuum Damage Model and
Its Application to Uniaxial Behavior of Asphalt Concrete,” Mechanics and Materials,
Vol. 24, No. 4, December 1996, pp. 241–255.