الفهرس 
CHAPTER (1) INTRODUTCIONOnly 14 pages are availabe for public view
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Abstract
In recent years, the use of nano materials for improving various mechanical and performance related properties of polymer modified asphalt binders have been growing rapidly. However, few researchers investigated the effects of base binder and styrene butadiene styrene (SBS) structure on rutting resistance of polymer nano composite modified asphalt mixtures.
In this research, two different nano materials and one additive were used with asphalt binder 60/70 to investigate the effect of using nano materials on the properties of bitumen and on the hot mix asphalt performance and properties. These nano materials and additive are nano clay (NC), nano silica (NS) and styrene- butadiene- styrene (SBS).
The nano clay (NC) and nano silica (NS) were first characterized using the transmission electronic microscope (TEM) in the dry powder state to determine their particle size distribution, the (TEM) analysis showed that most of NC and NS particles range size from 10 to 50 nm with some particles exceeded 100nm. During the mixing process, the binders were kept at 145 ± 5 and blended using a shear rate of 1500 (rpm) for approximately 60 min to ensure thorough dispersion. Scanning electronic microscope (SEM) was also used to observe the dispersion quality of the nano materials in the binder. The addition content of nano materials was (1%, 2% and 3%) blended with 5% SBS by weight of the base bitumen binder. The modified binder was screened and selected according to conventional performance indicators of asphalt binder, including penetration and softening point test. The results showed that the nano silica and nano clay with SBS decrease the penetration and increase the softening point.
Hot mix asphalt (HMA) mixtures were prepared and investigated by Marshall test. The results showed improvement in the stability, flow and Marshall quotient which indication of resistance against permanent deformation of asphaltic mixtures.
The optimal content from Marshall results was obtained at (3% NC+5% SBS) and (3% NS+5% SBS). In addition, the wheel tracking test was performed using this optimal ratio of addition. The results showed that the nano materials with SBS had an obvious effect on increasing the rutting resistance of hot mix asphalt mixtures.