Study On The Rheological Properties Of Carbon Nanotube/SBS Composite Modified Asphalt

SBS modified asphalt is widely used in road engineering due to its excellent high and low temperature performance,but it has the disadvantages of insufficient anti-aging ability and poor storage stability.In recent years,the application of nanotechnology in the field of transportation materials has become increasingly widespread,and nanomaterial modified asphalt is one of them.As one of the nanomaterials with excellent performance at present,due to the existence of a large number of conjugated ? bonds and ring structures in carbon nanotubes,it can be modified by incorporating it into SBS modified asphalt,which can improve the original disadvantages,further improve its road performance.In this paper,high-speed shearing method was used to prepare carbon nanotube/SBS composite modified asphalt with different contents.Through the basic index test method,the conventional performance indexes and viscosity of carbon nanotube/SBS composite modified asphalt binder before and after aging were studied.Through dynamic shear rheological tests,the main curves of complex modulus of carbon nanotubes/SBS composite modified asphalt with different contents were constructed,and its phase structure,high temperature performance,fatigue resistance and multi-stress repeated creep characteristics were analyzed.It shows that the incorporation of carbon nanotubes into SBS modified asphalt can significantly improve its high temperature rutting resistance and temperature sensitivity.The low-temperature creep characteristics of the composite modified asphalt were studied using a curved beam rheometer.The Burgers model was used to fit the low-temperature index.It was pointed out that the carbon nanotubes can improve the low-temperature performance of SBS modified asphalt at a lower content.By comparing the high and low temperature performance indexes of carbon nanotube/SBS composite modified asphalt under different aging conditions,it is found that the incorporation of carbon nanotubes can effectively improve its anti-aging performance.The compatibility,microstructure and chemical composition of carbon nanotube/SBS composite modified asphalt were tested by segregation test,fluorescence microscope and infrared spectroscopy.The effect of carbon nanotubes on the storage stability of SBS modified asphalt and its modification mechanism were analyzed.Considering comprehensively the high and low temperature rheological properties of carbon nanotube/SBS composite modified asphalt,it is concluded that the optimal content of carbon nanotubes is about 0.9%.