Evaluation of Effects of Filler By-Products on Fine Aggregate Matrix Viscoelasticity and Fatigue-Fracture Characteristics

Abstract

This study evaluated ornamental stone fines (OSF) and steel slag fines (SSF) as potential fillers for asphalt mixtures. The fine aggregate matrix (FAM) phase was chosen for performance tests. Four different types of FAM were produced, changing the type of filler among them. The effects of those materials on the FAM were investigated by performing dynamic frequency sweep tests to evaluate linear viscoelastic stiffness characteristics through the analysis of dynamic shear modulus master curve, and semicircular bending and time sweep tests to evaluate fracture characteristics through the analysis of fracture energy and damage characteristics based on the simplified viscoelastic continuum damage model, respectively. The results indicate that the FAM with a blend of OSF and SSF has better overall performance than the other studied FAMs, possibly due to its intermediate stiffening effect and higher resistance to fracture. It is also implied that the OSF and SSF by-products could be used as asphalt concrete filler, which can bring potentially significant environmental-economical benefits to countries such as Brazil, where those materials usually have been disposed.