Preparation Technology And Electro-thermal Characteristics Of Carbon Fiber/Graphene Conductive Asphalt Concrete

The surface function of roads is the basis for ensuring traffic safety operations.According to statistics,about 43% of China's land area is located in cold regions.There is a prominent problem that the ice and snow caused the lack of skid resistance and the safety of road traffic.It has caused great hidden danger to the normal operation order of the national economy and the safety of the people's life and property.In view of the road surface snow icing problem,more and more researchers are focusing on conductive asphalt concrete materials.At present,in the research field of conductive asphalt concrete,conductive fillers mainly consist of graphite,steel slag,carbon fiber,and steel fiber.Excessive conductive filler content,difficulty in balancing conductive properties and road performance,and other issues limit the further development and application of conductive asphalt concrete.In this context,the combination of carbon fiber and emerging carbon nano-materials graphene aims to prepare a conductive asphalt concrete that has excellent electrothermal characteristics with a lower conductive filler content,and at the same time satisfies the requirements for melting ice and snow and road performance.To provide theoretical and technical basis for ensuring the winter operation of asphalt pavement in cold regions.Firstly,starting from the asphalt binder,the effect of carbon fiber and graphene content on the resistivity of the asphalt binder was studied.The results show that both can effectively enhance the conductivity of the asphalt binder.At the level of conductive asphalt concrete,based on the characteristics of mesoscopic current distribution,the types of mixtures were selected to determine t he gradation of AC-13 mixture;the carbon fiber/graphene conductive asphalt concrete was determined by designing the resistivity of Marshall specimens.The preparation process,found that 9mm carbon fiber can play the best conductive effect.The use of fatty alcohol ether phosphate potassium salt pretreatment can enhance the dispersion of carbon fiber.Finally optimized design through the response surface design method to determine the carbon fiber and graphite With the best ratio of olefins,conductive asphalt concrete with a resistivity below 2.5 ??m was prepared.Secondly,the conductive properties and conductive behavior of conductive asphalt concrete have important effects on its practical engineering applications and conductive mechanisms.By testing the dependence of resistance of carbon fiber/graphene conductive asphalt concrete on external voltage,temperature and stress,the characteristics of volt-ampere characteristics,temperature-resistance and pressure-sensitive characteristics were studied.The results show that the resistivity changes significantly with the above factors,showing significant nonlinear characteristics.Using the dynamic random resistor network model,it is proved that the tunneling effect is the cause of the nonlinear volt-ampere characteristics.The conductive mechanism of carbon fiber/graphene conductive asphalt concrete was analyzed using the conductive theory of composite materials.It is believed that the conductive behavior of the carbon fiber/graphene conductive asphalt concrete is the result of the joint action of particle contact and tunneling.Thirdly,the influence of the addition of conductive filler on the thermal properties of asphalt concrete was studied.The results show that carbon fiber ca n significantly increase the thermal conductivity of asphalt concrete.Combined with the multiphysics simulation software Comsol Multiphysics,the temperature rising of the conductive asphalt concrete was analyzed by the factors of input power,constant pressure heat capacity,thermal conductivity and wind speed.The influence of input power on the heating rate of conductive asphalt concrete is most significant,a nd the process of melting snow was simulated and analyzed.The heating effect of carbon fiber / graphene conductive asphalt concrete was verified by indoor heating test and the simulation results were verified.Finally,the road performance was verified by laboratory tests.The results show that the high temperature stability,low temperature crack resistance,water stability,and fatigue resistance of the carbon fiber/graphene conductive asphalt coagulation meet the specification requirements,and the water stability is slightly With the exception of lowering,the remaining indicators are superior t o ordinary asphalt coagulation,indicating that they have the ability to be applied in practical projects.