Properties Research Of Carbon Nanotubes/SBS Composite Modified Asphalt And Mixtures

SBS modified asphalt is widely used at home and abroad for its excellent high and low temperature performance and good anti-deformation ability.But there are also some disadvantages of SBS modified asphalt,such as poor storage stability and poor anti-UV aging properties,etc.As a nanomaterial with excellent properties in mechanics,optics and electricity,carbon nanotubes are widely used.In this paper,SBS/CNTs composite modified asphalt was prepared by incorporating carbon nanotubes and SBS into virgin asphalt in order to improve the quality of SBS modified asphalt and promote the application of engineering practice.Three main indexes test,DSR test,BBR test,Brookfield viscosity test and indoor accelerated UV-aging test were carried out to evaluate the combination properties of composite modified asphalt.The raw carbon nanotubes was was modified and the effect of modification was characterized by infrared spectroscopy and X-ray diffraction test.The performance test of modified bitumen made of modified carbon tube and SBS was done and compared with raw carbon nanotubes.Asphalt mixtures were prepared and then immersion Marshall test,Hamburg rut test and low temperature bending test were applied to evaluate the effect of carbon nanotubes on water resistance,rutting resistance and low temperature cracking resistance of mixtures.The study found that:The softening point is slightly increased when add only the carbon nanotubes into asphalt,the ductility and penetration basically remain the same.The addition of carbon nanotubes shows increase in viscosity.The high temperature rheological property of modified asphalt at the addition dosage of 5%SBS+1%CNTs is better than that of SBS modified bitumen.Carbon nanotubes can not have a positive effect on the low temperature cracking resistance of bitumen.The composite modified asphalt has a lower degree of aging under the same conditions,showing excellent resistance of UV aging.The modified carbon nanotubes is attached to the silane molecules,and has no change in its crystal structure.The asphalt made of SBS/surface modified nano composites has higher ductility,softening point and high temperature grade,the anti-UV aging performance has also been improved,and the optimum dosage of two modifiers is still 5%SBS+1%CNTs.The composite modified asphalt mixture can further improve the rutting resistance compared with the SBS modified asphalt mixture,but the addition of carbon nanotubes show no obvious effect on the water resistance and low temperature performance.