Investigation on mixture recovery properties in fatigue tests

Abstract

In this paper the recovery properties of hot mix asphalt (HMA) mixture in fatigue tests are investigated based on dissipated energy approach. In order to determine the influence of material ageing, bitumen content, polymer modification and compaction energy on material ability to recover its initial characteristics, different variations of an asphalt mixture for surface course AC 11 D S were prepared. Recovery of material mechanical properties is observed during a single rest period, introduced into tension–compression cyclic fatigue tests under stress control. The analysis of the experimental results reveals that there is a significant influence of the duration of rest period on recovery capability. A plateau phase is achieved when the length of the rest period does not have any impact on asphalt recovery properties. Asphalt ageing plays an important role in reducing the effects of material recovery. The degree of compaction used in this research seems to have no influence on material ability to restore its initial properties. Mixtures prepared with additionally 0.5% of bitumen by mass show the best recovery characteristics compared to other variations.