| The highway transportation is an infrastructure which service for national economy, society development and people living, and is an important mark of a country's economic power and modernization level. The development speed of highway construction has a great meaning for promoting the development of national economy and pulling the development of other related industries.However, along with the high-speed development of the national economy in recent years, the traffic volume fast fiercely grow, the channelized traffic becomes obviously, and the proportion of large vehicle, heavy load and overload vehicle increases year by year, which make the traditional bituminous concrete pavement be seriously challenged. The disease of rut, relaxation , crack etc in the pavement become serious day by day, the phenomenon of asphalt mixture pavement's breakage in early days have occurrence between whiles. The researches show that the shortage of low temperature anti-cracking performance and high temperature stability of the asphalt mixture is one of the important factors which cause the asphalt mixture pavement to break in early days.Northeast region although take low temperature as its weather characteristics, the influence of the high temperature in summer upon the pavement also can't be neglected, according to the climate investigation in nine cities of Jilin region, the average temperature is 20℃in July, the highest temperature is above 32°C continuously for seven days, and take YanJi as highest, reach to 36℃, the high temperature weather (above 25℃) keeps on about one and half months. Once carried on an examination to the pavement temperature, the examination showed that the pavement temperature can reach to above 50℃, it can reach to above 52℃by adopting the pavement temperature computation formula present by SHRP. So the design of asphalt pavement in northeast region not only needs to consider the low temperature anti-crack performance, in the meantime still need to consider the high temperature stability. The exist research indicate that: mineral gradation is one of the important factors which influence the low temperature anti-crack performance and the high temperature stability of the asphalt mixture. So the research on the selection of mineral gradation in northeast region is very meaningful. The research about the gradation theory virtually originates from our country' s Duoji theories. But this theory hasn't got development on the application of gradation, mainly because there are large differences between theory model and actual circumstance. Take a wide view on the development of gradation theory, the commonly used are: Biggest Density Curve theory, Particle Interference theory and Fractal theory. Based on the above three kinds of gradation theory, the domestic and foreign scholars have carried on a thorough research on the calculation method of gradation theory and have obtained some beneficial results.The domestic road workers have carried on a thorough research on the high, low temperature performance of the asphalt mixture. For example Zhang Yiluo, Zheng Nanxiang pointed out that structure and parameters of the asphalt mixture determine the usage performance of asphalt pavement. Taking asphalt type, gradation, passing rate of 4. 75 mms and 2.36 mms, and filler to asphalt ratio etc as the basic parameters of the asphalt mixture. Starting from the macro characteristics of the mixture and with experimental method, we can open out the influence of each parameter on high and low temperature performance and variety regulation of the mixture. The results indicate: the variety of asphalt and the adjustment of structure have a great influence on the temperature stability; Along with the increase of passing rate of 4. 75 mm and 2. 36 mm , the high and low temperature performance of the asphalt mixture tend bad; The filler to asphalt ratio should take into comprehensive consideration in different types. Zhang Jun etc. studied the influence of modifier, stone gradation and asphalt grade on the low temperature anti-crack performance of asphalt mixture.But the existing research results are all single about the influence on high temperature stability or low temperature anti-crack performance of the mineral. The paper about influence of the same kind of gradation on high and low temperature performance of asphalt mixture hasn't been search out.The studies of this paper are mainly as follows:(1) Thorough analysis on gradation theory and the traditional theoretical gradation calculation method. Combining the Superpave gradation design method, Bailey method and on the foundation of gradation type in our country's criterion, study out five kinds of gradation, these five kinds of gradation will be used in the study of the influence of mineral gradation on high and low temperature performance (namely textual chapter 3, chapter 4).(2)Probing into the reason of low temperature crack in asphalt pavement, thorough analyzing the evaluation method of the low temperature anti-crack performance of asphalt mixture. On this foundation, evaluating the low temperature anti-crack performance of the five kinds of different gradation asphalt mixture by choosing the restrained specimen temperature stress experiment, the low temperature flexural experiment, and low temperature flexural and creep experiment.(3)Thoroughly analyzing influence factors of a high temperature stability of the asphalt mixture. On this foundation and by rutting test, studying the influences of different aggregate grain-diameter, mineral aggregate gradation, and binder dosage on high temperature stability respectively, finally give an evaluation of high temperature stability of the asphalt mixture of five different kinds of gradation.(4)Comprehensively considering the low and high temperature performance of the five kinds of gradation of asphalt mixture, and selecting a kind of mineral gradation which suits for northeast region.
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