Performance characteristics of asphalt mixtures with industrial waste/by-product materials as mineral fillers under static and cyclic loading

The mineral filler is an integral constituent of asphalt mixture, which affects its performance. This research investigates the effect of using four local industrial waste/by-product materials (marble, granite, steel slag and hydrated lime powder) as mineral fillers on asphalt mixtures characteristics. The detailed performance of these materials as well as asphalt binder and asphalt mixture characteristics are presented. In Egypt, limestone powder is a typical mineral filler in asphalt mixture composition. A control asphalt mixture with limestone mineral filler is designed using Marshall method. Other four asphalt mixtures are prepared using similar constituents and volumetrics except replacing the limestone filler with other types of industrial waste/by-product materials, while maintaining the same percentage of mineral filler as in the control mix. Marshall stability and moisture-induced damage of the investigated asphalt mixtures are determined and compared to the control asphalt mixture results. In addition, the performance characteristics of the investigated mixtures are evaluated by conducting cyclic performance tests including the dynamic modulus (E*) and flow number (FN). Testing results show that the asphalt mixture containing marble as a filler yields the highest stability; while, the hydrated lime filler noticeably enhances the performance of the asphalt mixture in terms of moisture damage resistance, E*, and FN. Unexpectedly, steel slag filler does not improve the asphalt mixture performance. Finally, the stiffness of the investigated mixtures is evaluated using three well-known E*-predictive models (NCHRP 1-37A, Hirsh, and NCHRP 1-40D); while, the resistance of the investigated mixtures to permanent deformation is evaluated using a calibrated version of Apeagyei-literary model based on the investigated mixtures to predict FN at 54.4°C and 1 Hz frequency.