Multiscale investigation of the impact of filler on asphalt concrete behavior -

Abstract

This study evaluates the effect of different types of natural and by-product filler properties on asphalt mastics. Seven types of fillers, namely; Gabbro, Basalt, Limestone Lebanon, Limestone Qatar, Lime, Hydrated Cement, and Recycled Concrete Aggregate were blended with one type of binder. Extensive laboratory testing is considered, including filler characterization (surface analyzer, scanning electron microscope, X-ray diffraction, methylene blue value, etc.) and rheological testing of mastic (dynamic shear rheometer, multiple stress creep recovery, rotational viscometer). Furthermore, the asphalt mixes with different fillers were evaluated for moisture damage by ultra sound accelerated condition test which is energy based test evaluates the mix performance under moisture conditions. Finally, a statistical analysis was conducted to investigate the correlation between the filler properties and mastics performance. Furthermore, comparison between the filler properties and their mastics was conducted using Tukey post hoc analysis. The study results reveal that lime as filler significantly affect the resistance of moisture damage and rutti2ng and fatigue cracking, in addition, the recycled concrete aggregate filler shows a higher performance compared to natural filler therefore, as a consequence, it is a sustainable and cost effective replacement solution. The prediction models for ∣G∗∣ and Jnr show good agreement with testing data. Also, this study illustrates the considerable influence of the methylene blue value as indicator for mastics performance.