The Research On Temperature Distribution Of Asphalt Pavement In Yunnan Province

Asphalt is a typical material which is sensitive to temperature. Mechanical properties and pavement performance vary greatly with the temperature difference. If it is possible to predict exactly the temperature profiles in asphalt pavement based on solar radiation and air temperature and so on, the pavement structure design methods will be greatly improved and it will become the reality that using different grade binders in different layers as a more economical method compared with the traditional way. Besides, the time of asphalt pavement temperature at different temperature range will affect the accuracy and scientificity of the asphalt grade selection.In order to solve the above problems, this paper firstly analyzes the meteorological elements which affect the condition of pavement temperature, and determines the main elements which affect pavement temperature. According to the meteorological data from 1978 to 2007 in Yunnan province, together with the measured data in test road, it gets the changing regulation of meteorological elements. Then, based on the primary theories in the thermology, and after itemizing the flaws in existing pavement temperature prediction theoretical methods. One-dimensional non-steady-state heat transfer model of asphalt pavement was established. Implicit scheme is derived using asphalt mixed boundary conditions for different expression and using matlab7.0 language developed asphalt pavement temperature calculation program.On the basis of the extensive literature, the reasonable range of asphalt pavement materials thermo-physical parameters has been identified, using the calculation program to calculate the temperature of asphalt pavement, and the comparison with measured data, the reasonableness and accuracy of the computational model has been validated. Based on the temperature factor played a leading role in the calculation model, with average daily maximum temperature in July for the high-temperature indicators, and the average minimum temperature for the low-temperature indicator, got the temperature divisions of Yunnan province, the relationship of meteorological factors in different temperature divisions has been revised, so that the calculation model can be widely used in Yunnan province. Finally, according to the results of asphalt pavement temperature calculation,5℃ temperature range is given for the asphalt pavement temperature distribution of central regions in different months. On this base, it further shows the temperature region of Yunnan province’s five full-year asphalt pavement temperature distribution for the first time. The choice of the asphalt binder gives specific recommendations, which made the selection of Asphalt materials in Yunnan Province more scientific.