Testing and Modeling of Fine Aggregate Matrix and Its Relationship to Asphalt Concrete Mix

Abstract

The study of the fundamental properties of asphalt concrete (AC) can be used to improve and maximize the performance potential of these materials. In this paper, the fundamental approach is examined by coupling its essential hypothesis to an investigation of AC across multiple length scales. Asphalt and aggregate materials from the state of Arizona were used to prepare fine aggregate matrix (FAM) and AC samples. Laboratory tests on these materials were conducted to investigate the modulus and damage characteristics for two binder types. A comparison of mechanical response across length scales is not new, and the unique element of this study is testing both materials in the axial direction (tension–compression) for both modulus and fatigue. A strong relationship between these two materials was observed; this relationship suggests that tests on FAM samples can provide much needed insight in understanding the behavior of AC for various conditions. The study also investigated upscaling of the FAM properties to those of the AC mixture through a homogenized continua approach. Multiple upscale models were evaluated in this upscaling process, but the chosen method produced the best overall match to experimental data. The findings from this modeling effort were also used to upscale the behaviors of FAM to identify the fatigue characteristics of AC mixtures and evaluate the long-term performance of the material.