Structural Design And Thermal Conductivity Analysis Of Targeted Heat Conduction Pavement Based On Carbon Fiber Sheet Heat Source

The snow and ice problem of roads is one of the main problems affecting traffic safety,especially in the cold areas in winter or in special road sections such as bridges,the snow cover problem at the tunnel entrance seriously reduces the efficiency of vehicles and increases the hidden danger of safety.In addition,summer high temperatures can easily cause road rutting and other diseases.There are already many kinds of snow and ice removal technologies,including cables,carbon fiber sheets and other active heating methods.Heat conductive asphalt concrete is used to improve heating efficiency.However,high thermal conductivity makes the application of thermal conductivity asphalt concrete pavement in winter and summer contradictory.On the basis of heating pavement with carbon fiber sheet,the paper puts forward the structure of target heat conductive asphalt pavement,which is to eliminate this contradiction by the combination of high thermal conductivity asphalt concrete structure layer and low thermal conductivity asphalt concrete structure layer.The optimum combination of thermal conductivity is obtained by numerical simulation of the temperature field and the influence of the content of thermal material on the thermal conductivity.Heating test,road performance test and economic evaluation were carried out.The influence of various thermal conductors on the thermal conductivity of graphite,diatomite and zeolites with high thermal conductivity and low thermal conductivity was measured by DHR plate method.The standard part experiment is used to calculate the amount of filler needed according to the thermal conductivity.Based on the finite element analysis of the thermal conductivity of the target heat conduction pavement structure by ANSYS,it is proved that the pavement structure can not only achieve the heating efficiency of carbon fiber cloth in winter,but also reduce the temperature of the middle surface of the pavement structure under high temperature in summer.The thermal conductivity of high and low thermal conductivity layers is 2.4W/(m·K)and 0.8W/(m·K),respectively.The optimum thickness ratio and size of high and low thermal conductivity layers are obtained by dimension analysis.Based on the results of thermal conductivity experiments,four gradient distributions were selected for the high thermal conductivity of 1.8 W/(m·K)?2.0 W/(m·K)?2.2 W/(m·K)?2.4 W/(m·K)and a low thermal conductivity of 0.4 W/(m·K)?0.5 W/(m·K)?0.6W/(m·K)?0.7 W/(m·K)?0.8 W/(m·K).The temperature field of 20 target thermal conductive asphalt pavement was simulated in winter and summer,and a reasonable combination of thermal conductivity was obtained.The carbon fiber cloth is applied to the heating heat source of the pavement.Through the simulation of the temperature field of the pavement structure under the strip and block arrangement of the carbon fiber sheet and the laboratory test,the better layout mode and the distribution density range are obtained.And related indoor heating test was carried out.According to the optimum combination of thermal conductivity obtained by finite element simulation,the optimum proportion of each filler was obtained by standard part experiment.After the proportion design,the indoor heating test of carbon fiber sheet was carried out.It is proved that the thermal conductivity and application effect of the target thermal conductive pavement.The high temperature stability test,dynamic modulus and SCB performance test of the pavement structure are also carried out,which proves the feasibility of the target heat conduction pavement structure.Finally,the economic analysis and evaluation of the target thermal conductive pavement are carried out.