Aggregate Maximum Nominal Sizes' Influence on Fatigue Damage Performance Using Different Scales

摘要

Some researchers have used the fine aggregates matrix (FAM) as a means to evaluate the influence of material properties on the expected changes in the performance of hot mix asphalt (HMA). Based on the most commonly used definition, the FAM is composed of part of the fine aggregates (smaller than 1.18 mm), mineral filler, and asphalt binder. Different studies have used different methods to design such FAM mixes. In this study, the fatigue characteristics of different FAM designs (by varying their maximum aggregate size and binder content) were evaluated and compared to the fatigue characteristics of a corresponding full asphalt mixture. The goal of this exercise was to identify a FAM design that was most similar to the full asphalt mixtures in terms of its damage characteristics. The viscoelastic continuum damage approach was used to make such comparisons. Results show that FAM mixes with a maximum nominal aggregate size (MNS) of 2.00 mm have similar damage evolution trends as that of the full hot mix asphalt with a maximum aggregate size of 12.50 mm. Also, through the results and using a failure criterion based on energy, cyclic tests can be simulated at different loading conditions in order to construct Woehler curves. The results showed that smaller MNS mixtures present better damage performance for strain levels lower than 500 microstrain.