Study On The Performance Of Composite Modified High Viscous Asphalt And Mixture

Drainage asphalt pavement is a new type of multifunctional pavement that has been vigorously promoted in China in recent years.It has functions such as drainage,anti slip,and noise reduction,which meets China’s needs for green,safe,and ecological development.However,the high porosity structure leads to a significant decrease in the anti deformation and anti flying performance of the road surface.More prone to rutting,flying and other diseases,seriously affecting the service life and long-term performance of the road surface.The most direct and effective method is to use high viscosity modified asphalt with better performance.However,the research on high viscosity modified asphalt in China is not yet complete,and there is an urgent need to develop a high viscosity modified asphalt with better performance and stronger adaptability.Therefore,this article uses high-performance TPS modifiers to modify SBS asphalt,prepare a new type of composite modified high viscosity asphalt,and conduct in-depth research on its performance.Firstly,the preparation process of composite modified asphalt is determined through three major indicators of asphalt testing.Then the macro and micro performance tests were carried out on the composite modified asphalt with 6%,9% and 12% TPS content to study the effects of TPS content on 60 ℃ dynamic viscosity,anti-aging performance,25 ° relative density,microstructure of modifier and chemical functional group composition.Main conclusion:(1)The optimal shear time for composite modified asphalt is 30 minutes,and the selection range of TPS content is 6.4%～12.9%.(2)TPS can significantly increase the 60 ℃ dynamic viscosity of asphalt and reduce its temperature sensitivity.(3)TPS adsorbs SBS modifiers and forms a linear fibrous structure.(4)The composite modification process does not undergo chemical reactions,and TPS is mainly composed of alkanes,cyclobenzene,and a small amount of polybutadiene and polystyrene.Secondly,this article conducts in-depth research on the rheological and adhesive properties of composite modified asphalt.Using dynamic shear rheometer(DSR)to study the rheological properties of asphalt from multiple perspectives.Then,based on the surface free energy theory and combined with contact angle tests,the adhesion performance is evaluated using adhesion work,adhesion work,peeling work,and energy ratio ER values.Main conclusion:(1)TPS can expand the linear viscoelastic zone of asphalt and effectively improve its deformation resistance at high temperatures and frequencies.(2)TPS can significantly reduce the permanent deformation of asphalt under a stress of 100 Pa,promoting the rapid entry of asphalt into a stable state.(3)TPS can effectively increase the cohesion and adhesion work of asphalt,significantly improving its adhesion performance.The increase in energy ratio ER results in a significant improvement in water stability.Finally,mix design and verify the road performance of PAC-13.Then,through lowtemperature bending comparison test,Marshall comparison test,splitting comparison test,and permeability coefficient comparison test,the influence of different environments on the road performance of the mixture is studied.The results indicate that:(1)PAC-13 specimens characterizing different environments can meet the specification requirements for road performance,so composite modified asphalt has strong environmental adaptability.(2)The long-term high-temperature environment poses the greatest harm to drainage asphalt pavement.(3)Long term wear can significantly reduce the mechanical properties of the road surface,but it will not affect water stability.(4)Freezing and thawing can enhance the overall anti splitting strength,but it will reduce the local anti splitting failure strength.