Experimental Analysis On The Characteristic Of Heat Transfer For Asphalt Pavement

Asphalt mixtures used for highway engineering is a kind of classic visco-elastic-plasticmaterial, and the mechanical properties and performance of asphalt mixtures are obviouslysensitive to temperature. Temperature could directly affect the mechanical characteristics andperformance of pavement, especially in the summer, asphalt pavement absorbs lots of heatdue to the influence of solar radiation and high temperature, and the heat could be constantlytransferred from pavement surface to bottom, making asphalt pavement keep in hightemperature condition for long time. In this case, asphalt pavement under heavy traffic andrepeated loadings is very easy to appear rutting and other diseases, which do great harm to theservice quality of asphalt pavement. Therefore, it is of great need to carry out the research onthe characteristic of heat transfer for asphalt pavement, which has important theoreticalsignificance and practical value for deep studying the mechanical properties of pavementmaterials and durability of asphalt pavement.In this paper, firstly, aiming at the heat exchange of asphalt pavement, the influencefactors such as pavement solar-thermal environment and materials that affecting heat transferof pavement were analyzed comprehensively. Based on this, the thermal equilibrium equationof pavement and analytical solution of the temperature field were established, it was foundthat the surface properties could affect the temperature of pavement obviously, but theinfluence of thermal physical parameters influence was not observable. Moreover, accordingto Fourier’s law, thermal conductivity detector was designed and developed to test the thermalconductivity of asphalt mixtures, experimental results showed that thermal conductivity wasnot a fixed value and varied with the change of temperature. Besides, the test technology ofpavement temperature field was introduced, and the heat change of asphalt pavement wascalculated by using the experimental data, meanwhile, the heat transfer variation laws ofasphalt pavement in the weather of cool winter and hot summer were obtained. For the ruttingdisease, through further studying the heat storage and high temperature state of asphaltpavement, it was obtained that the rutting was mainly occurred in summer which accounts forabout91%of the total rutting development time. Finally, based on the research of functionalmaterials, a new philosophy for improving the high temperature properties of asphalt pavement was put forward, and it was showed that the temperature of pavement in hottemperature period of summer could be significantly reduced by using the new insulationmaterials.