Study On Preparation And Properties Of Graphene Conductive Asphalt Concrete

There are a lot of road icing phenomena in low temperature conditions in winter in China.For asphalt concrete pavement,road icing will greatly threaten driving safety and comfort,and will have a greater adverse impact on national economy.Therefore,it has great significance for the study of road snow melting and ice melting.Among many schemes of snow melting and ice melting,conductive asphalt concrete has many advantages,such as no impact on traffic,convenient application,high timeliness,green environmental protection and so on.It is a research hotspot at present.Referring to the current research results,it is found that the conductive phase materials of conductive asphalt concrete are mostly concentrated on graphite,steel fibers and carbon fibers.These materials have some shortcomings,such as excessive content,poor conductive effect and great negative impact on road performance,which restrict the application of conductive asphalt concrete in snow melting and ice melting.Therefore,based on graphene and carbon fiber as conductive phase materials,the conductive asphalt concrete with excellent outlet performance,conductive performance and electrothermal performance is prepared under reasonable dosage,so as to ensure the normal use of roads in cold areas in winter and solve the adverse effects of road icing on transportation.Firstly,the conductive properties of conductive phase materials,aggregates,asphalt and other raw materials are tested.By comparing the conductive properties of conductive asphalt concrete prepared with different conductive phase materials,the conductive schemes of conductive phase materials with graphene and carbon fibers are determined.The dispersion of graphene and carbon fibers in conductive asphalt concrete was studied.Based on the distribution characteristics of conductive phase materials in different types of asphalt concrete structure,the scheme of using AC-20 as conductive asphalt concrete gradation was determined.The gradation of mineral,the content of conductive phase materials and the optimum asphalt content were further determined through experiments,and the mixing of conductive asphalt concrete was also determined.A conductive asphalt concrete with resistivity of 4.63?·m was prepared by comparing the combined forming methods.Secondly,the high temperature performance,low temperature performance and water stability of the prepared conductive asphalt concrete are tested.The results show that the pavement performance of the prepared conductive asphalt concrete is better than that of ordinary asphalt concrete,which shows that it can be better applied in engineering practice.Thirdly,the conductive properties of Marshall specimens and rutting slab specimens of conductive asphalt concrete are studied by two-electrode method which is more in line with the actual application.The conductive mechanism of conductive asphalt concrete is studied.The influence mechanism of graphene and carbon fibre on conductive properties of conductive asphalt concrete is analyzed.It is considered that the contact effect and tunnel effect have influence on conductive properties of conductive asphalt concrete.The most significant effect is that carbon fibers form the conductive network mainly through the contact effect.The addition of graphene can significantly improve the contact effect and tunnel effect of the conductive network,thus enabling conductive asphalt concrete to have excellent conductive properties.Finally,the electrical and thermal properties of conductive asphalt concrete are simulated in the laboratory.The experimental results show that the prepared conductive asphalt concrete has good electrical and thermal properties,especially in the case of large input power,it can melt snow and ice very efficiently.The paper also puts forward effective ways to improve the snow melting and ice melting efficiency of conductive asphalt concrete,and designs the structure of conductive asphalt concrete pavement,so as to make it have higher application value.