Assessments of moisture damage resistance of asphalt concrete mixtures and asphalt mastic with various mineral fillers

Abstract

Resistance to moisture damage is crucial for asphalt concrete. Fine-particle mineral fillers have been used to leverage such resistance. This study examines the effects of different types of mineral fillers on the rheology and resistance to moisture damage of asphalt binders and asphalt concrete mixtures. These mineral fillers, namely baghouse dust, lime kiln dust, and hydrated lime, were targeted in this study. These fillers were added to two types of asphalt binders during the initial stage to examine their effects on the rheology of the binders with dynamic shear modulus tests. The effects of the fillers on affinity were evaluated through rolling bottle tests. It was found that mineral fillers can stiffen asphalt binder/mastic, thus providing a higher dynamic shear modulus and better affinity and moisture resistance in terms of a higher percentage of asphalt binder coverage. The properties of asphalt materials were influenced more by filler type than binder type. Hydrated lime provided superior results compared to the others. Consequently, the hydrated lime was used to examine the moisture resistance in the mixture scale in the final stage. It was found that the stiffening behavior can be attributed to the moisture resistance properties in the binder/mastic scale.