Influence of mineral filler particle size and type on rheological and performance properties of SMA asphalt-filler mastics

Abstract

The performance of fillers in Stone Mastic Asphalt (SMA) pavements is unclear due to the various interaction effects of filler with asphalt binders, depending on the filler percentage, type and particle size. In this study, a laboratory investigation was conducted on the properties of asphalt binder and filler as a function of type and particle size. One asphalt binder and four filler types with different mineralogy were selected to assess the filler particle size and type effect. The selected fraction of mineral filler was blended with the asphalt binder in three different size proportions of 100/0, 50/50 and 0/100 passing the 75/20 micron sieve. To investigate the influence of filler particle size and type on mastics rheological and performance properties, Dynamic Shear Rheometer (DSR) was used over a broad range of temperatures and aging. The data obtained from this study led to the evaluation of the effects of filler type and the particle size on mastic performance. The analysis of data at the given filler/asphalt ratio showed that medium to coarse particle size filler improves the rutting and the coarse to medium particle size improves the fatigue cracking resistance of the tested mastics. Furthermore, the results from this study indicated that the fine particle size mastics seemed to lead a lower viscosity, higher penetration and lower softening point. The ceramic filler regardless the particle size was found to be more effective on producing mastics that are more elastic and less susceptible to rutting and cracking than the control mastic. © 2012 Knowledgia Review, Malaysia.