Analysis On Optimization Design And Viscoelastic Response Of Conductive Asphalt Pavement Using Snowmelt

It is a common research topic of many experts and scholars at present to design a type of conductive asphalt pavement which can be used to melting snow and ice in winter on the basis of the advantages of asphalt pavement itself. In the study, how some parameters affect the cooling in summer and melting snow of asphalt pavement in winter is analyzed. The parameters involve the thermal conductivity of asphalt pavement, the depth of heat exchange tubes and distances between tubes etc. And the logical depth of interred tubes and distance are given. Especially, the cooling and melting snow experiments of asphalt slabs are done in laboratory. The viscoelastic response of the conductive asphalt pavement with the logical depth of interred tubes and distances is analyzed in moving load. And the design fatigue life of the conductive asphalt pavement is forecasted. The study is expected to play a guiding role in structural design of the conductive asphalt pavement and have important practical significance in the cooling and melting snow of airport runway, road and bridge.The melting snow and ice performance of the conductive asphalt pavement with different interred tubes' ways is studied using the finite element software ANSYS. And the design of the heat exchange tubes' arrangement is optimized. The relation of the beginning melting-ice time of the conductive asphalt pavement and the thermal conductivity of asphalt pavement can be described by exponential function. The deeper the tubes are interred, the better to increase the thermal conductivity of asphalt pavement may improve the performance of melting snow and ice. The logical arrangement ways of the heat exchange tubes in the conductive asphalt pavement whose thermal conductivity is more than≥3.0W/(m·℃may be the following:(1) The distance between tubs is 0.1m when the depth of interred tubes is 10cm; (2) The distance between tubs is 0.15m when the depth of interred tubes is 4cm.The temperature distribution of the conductive asphalt pavement in summer is simulated by ANSYS. The results show that the 2cm from the surface to bottom is the maximum temperature of the asphalt pavement. To choose the conductive asphalt pavement can decrease the maximum temperature more than 3.8%. The road surface and internal temperature can be reduced effectively when the heat exchange tubes are full of cooling agent-water. And the decreasing temperature range is more than 20% when the thermal conductivity is 3.0W/(m·℃).The viscoelastic response of the conductive asphalt pavement with the logical depth of interred tubes and distances is analyzed in moving load using the finite element software ABAQUS. The transition method from viscoelastic constitutive relation of asphalt mixture to Prony series is given. The maximum tensile strain appears in the bottom of the bottom asphalt layer whether the pavement is conductive with interred tubes or common. The heat exchange tubes can weaken the maximum tensile strain of the bottom of the middle layer effectively. Whether the heat change tubes are interred in asphalt pavement has little effect on the fatigue life of the asphalt pavement. The asphalt pavement with tubes can be designed using the same method as the asphalt pavement without tubes.