Assessment of healing properties of asphalt mixtures

Abstract

Fatigue failure due to repeated traffic loading is a significant distress for asphalt pavements. Nevertheless, the damage associated to this phenomenon can be partially or entirely recovered during rest periods between loading repetitions, potentially resulting in a longer pavement service life. In this paper, the results from a comprehensive investigation on healing potential of asphalt materials are presented based on cyclic uniaxial tension compression fatigue tests under stresscontrol mode with and without rest periods. Then a new healing index parameter is proposed and evaluated using a testing procedure with different rest period durations. The analysis of the experimental results reveals that the newly developed healing index effectively asses the mixtures healing properties with an increasing trend for longer rest periods. A limit plateau value is then achieved when the duration of the rest period does not any longer affect the asphalt healing properties. The proposed healing index provides a simple and practical tool for optimal pre-selection of pavement materials, which can be used on a routine basis.