The influence of micronized rubber powder and rice husk ash on mechanical, physical and rheological characteristics of asphalt binders and mixtures at high temperatures

This research target to examine the effectiveness of adding rice husk ash and micronized rubber modifier powder (MRP) on mechanical and physical properties as well as rheological characteristics of bitumen binders and mixtures within elevated temperatures. Three concentrations 2%, 4%, and 8%, and 6%, 12%, and 18% of RHA and MRP respectively were employed to prepare modified asphalt specimens in addition to the control specimens. To straighten the features of asphalt binders and mixtures, several experiments were conducted like penetration, softening point, elastic recovery, wheel tracking test, and rotational viscosity tests which are assessed with basic tests, while rheological characteristic tests as dynamic shear rheometer test are conducted to measuring material's flow and deformation properties under stress, measured by using DSR devise which is considered as the most advanced rheometer's devise. Obtained results showed that, RHA and MRP had affirmative leverages on properties of asphalt binder and mixtures. Besides, the new hybrid modified asphalt with percentage of 8% RHA and 18% MRP could be deemed as the best favorable dosage for premium overall rendering of amended blends and binders.