Experimental Study On The Heat Conduction Of Asphalt Mixtures

As a kind of typical visco-elastic-plastic material, asphalt mixture is widely used in thesurfacing of the asphalt pavement and is susceptible to the changing of the temperature, itsmechanical characteristics and pavement performance are directly affected by the temperature.As it refers to the asphalt pavement located in different temperature, the destroy forms arequite dissimilar, e.g. It tends to rutting in high temperature, as well as cracking in lowtemperature. However, since the distribution diversity of temperature is the result of heatconduction in the internal pavement, to achieve the purpose of improving the thermal field ofasphalt pavement, and then enhancing its pavement performance, the thermal conductivity ofasphalt mixture would be studied through the heat conduction experiment developed by ofrelevant equipments in the paper, which will provide a fresh idea and method to the study ofmechanical characteristics of pavement material and long-term pavement performance ofasphalt pavement.Based on the Fourier law, heat conduction of asphalt mixture is analyzed. According tothe principle of one-dimensional steady heat conduction, a whole set of heat conductionexperimental device of asphalt mixture is developed by ourselves. Heat conduction test isproceeded with the application of the developed device, and it comes to the conclusion thatthe thermal conductivity of asphalt mixture, which vary according to the different materialand gradation, but the difference is not obvious. In addition, in the range of20℃to60℃, testresults show that the thermal conductivity of asphalt mixture has a range of values from1.07to1.90(w/m·k), and with the rise of temperature it becomes much bigger. Finally, on the basisof the analysis of heat conduction and with the actual research of thermal field of asphaltpavement of supported project of Guang-ba freeway located in Sichuan province, as well asthe help of finite element analysis model, the influences of the heat conduction of asphaltmixture on the temperature field and temperature gradient of the asphalt pavement areobtained by changing the thermal conductivity of asphalt mixture.