Optimization of Fine Aggregate Matrices Mix Design and Fabrication Using Criteria Derived from Experimental Data

Abstract

Fine aggregate matrices (FAMs) have been identified as a key constituent of asphalt concrete (AC). To accurately analyze the behavior of FAM testing specimens that represent the actual material in asphalt mixtures, mix design procedures must consider the inherent characteristics of the source material. These characteristics are often not directly obtained from tests and are instead assumed or adopted from tables available in the literature. Examples of such characteristics include specific surface area and maximum size of aggregates, binder film thickness, and the percentage of air voids to be used in sample fabrication. To enhance FAM mix design, this study incorporates characterization results of the aforementioned parameters, obtained through laboratory and digital image analysis techniques, into an existing FAM mix design concept. The findings indicate that FAMs designed using the recently developed procedures have the potential to ensure a simplistic relationship between the dynamic modulus of the FAM and its corresponding AC and to better predict the fatigue cracking phenomenon through the strain ratio relationship between the different material scales. As a result, the novel optimized FAM mix design holds great promise as a tool for predicting the overall behavior of asphalt mixtures using multiscale-based approaches.