| Summary: | This study was conducted to investigate the performance characteristics of polymer modified bitumens (PMB) mixed with nanosilica (NS). PMB, PG 76 and NS were mixed with concentration of binder weight at 0, 2, 4 and 6 %. During the course of the mixing process, the binders were kept at 163 °C and blended using a shear rate of 3000rpm for 1 h. As a result, microstructure examination, effects of NS on storage stability, and physical and rheological properties were investigated. Besides that, requirement tests such as penetration, softening point, ductility, viscosity and rheological analysis, such as isochronal plot, master curves, black diagram and SHRP parameters, are also conducted. SEM result revealed that NS particles disperse well in the bituminous binder matrix and the addition of NS into PMB will enhance the viscosity and ductility. The study result also revealed that nanosilica-modified bitumen binder storage capability is dependent on NS content. Based on the dynamic shear rheometer test, the addition of NS also increased the complex modulus G* at a lower frequencies and/or high temperatures compared to PMB binder, thus increasing the rut factor, causing higher rutting resistance. In contrast, at high frequencies and/or intermediate temperatures, G* decreases leading to improved fatigue behaviour at temperatures lower than 40 °C. Overall, the findings from this study can be concluded that the addition of 6 % of nanosilica is the optimum content to improve the performance characteristics of polymer modified bitumen.
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