Effect of Various Nanoclay on the Reological Behavior of Bitumen

In this research bitumen has been modified with adding different nanoclay by melt blending with montmorillonite nanoclay (MN), expanded vermiculite nanoclay (VN) and organic rectorite nanoclay (RN). The morphology of the nanocomposites was characterized by X-ray diffraction (XRD).The binders were aged according to the thin film oven test (TFOT) and pressure aging vessel (PAV). The effect of nanoclays on the physical and aging properties of the bitumen was investigated. XRD shows that RN and MN modified bitumen’s form the intercalated nanostructures, while the VN modified bitumen forms the exfoliated nanostructure. The addition of nanoclay to the bitumen increases both softening point and viscosity of the bitumen. Compared with RN and VN modified bitumen’s, the MN modified bitumen shows the higher increase in softening point and viscosity as well as the low temperature ductility. As a result of TFOT and PAV aging, the mass change rate and viscosity aging index of the bitumen are decreased due to the introduction of nanoclay, indicating the good aging resistance of nanoclay-bitumen nanocomposites. MN has more pronounced improvements in aging resistance of bitumen in comparison with RN and MN modified bitumen’s due to the formation of exfoliated structure.

Keywords:

modified bitumen , reological behavior , nanoclay , nanocomposites , aging