الفهرس | Only 14 pages are availabe for public view |
Abstract Among the nanomaterials, nanosilica (NS) is widely used in asphalt modification research. However, the high price and limited available quantities of NS interdicts its practical use in pavement construction. This study attempts to find viable alternatives that offer a comparable performance of NS. Raw nanoclay (NC) and nano-silica fume (NSF) are the suggested alternatives for this purpose. Therefore, NSF as an industrial waste material was employed at low contents (2, 4, 6, and 8%) and high contents (20, 30, 40, and 50%) by asphalt weight as modifying additives to the asphalt binder. Besides, NC was used at the content of 2, 4, 6, and 8% by asphalt weight. While NS was employed at the content of 2, 4, and 6% by asphalt weight for the comparison purpose. The asphalt samples were mixed with nanomaterials using a high-shear mixer at various speeds and durations to select the appropriate mixing conditions to achieve a homogeneous blending. Transmission Electron Microscopy (TEM) was used for scanning the nanostructure particles and Scanning Electron Microscopy (SEM) was performed to assess the homogeneity of modified binders. Changes in the chemical bands of the modified asphalts were investigated using Fourier Transform Infrared Spectroscopy (FTIR). The physical- rheological properties, temperature susceptibility, aging effect, and economic benefit of the modified binders were also investigated. In addition, prediction models were utilized to predict the rutting parameter (G*/sinδ) ِِof ِِ the modified asphalt. Moreover, the effect of modified asphalt on the concentrations of environmental and healthy harmful metals in the leachate water was investigated. The stiffness, moisture damage, rutting, and fatigue of the hot asphalt mixtures prepared with modified binders were evaluated using Marshall, indirect tensile strength, and double punching tests. Moreover, the Mechanistic-Empirical Pavement Design software (AASHTOWare Pavement iii ME Design) was used to predict the field pavement performance of both the control and modified asphalt mixtures |