Laboratory Performance Evaluation of Modified Asphalt Mixtures for Inchon Airport Pavements

Abstract

In this paper, fatigue and rutting characteristics of various modified and unmodified mixtures are evaluated using uniaxial tension and triaxial compression cyclic tests, respectively. The fatigue and healing behavior of the mixes is presented by means of the viscoeiastic, continuum damage (VCD) model previously developed by the authors. Since the VCD model takes the same form as the classical, strain-based fatigue model, the coefficients in the classical model are described in terms of fundamental material properties and test conditions in the VCD model. The explicit form of the VCD model and different performance data from all the mixes are used to investigate the effects of the material properties on the fatigue life and microdamage healing potential of asphalt concrete. Structural analysis based on the multi-layered elastic theory is conducted to compare the fatigue lives of the various mixes in pavement systems. A simple permanent deformation model that correlates vertical permanent strain and number of applied loads is used in representing the data from the triaxial compression tests at different confining pressures. The modified mixtures demonstrate better rutting resistance as expected, although the ranking among the modified mixtures changes depending on the confining pressure. The role of additive at high temperatures and different gradations and binder contents used in the modified mixtures seem to explain these observations.