Research On Aggregate Gradation Optimization And Fractal Of Asphalt Mixture

With the rapid development of China's highway in recent years, asphalt pavement has been widely used, but at the same time there have great hidden dangers in qualitative issues, especially the lack of durability and early damage. The main reasons of causing these problems include the construction-level restrictions, the traffic volume rapid growth and poorly-graded, so the graded of asphalt mixture aggregate has to be optimized to obtain a high road performance. Fractal is a new theoretical tool to study lots of statistical self-similarity characteristics in nature, and it has a powerful function in describing and evaluating those phenomena continuous in scale, erose in shape or stochastic in distribute. There are so many self-similarity characteristics in asphalt pavement from the selection of raw materials, the design of gradation, until to the construction of pavement. Traditional indexes based on experience are difficult in describing and evaluating, so we can turn to the fractal theory to give them a quantitative analysis.This paper takes the graded mean value by standardize requirements as optimal goal, optimizes the graded of asphalt mixture aggregate by using the multi-goal decision optimal theory, establishes computer program by using MATLAB, bases on outlining the optimization of the graded of asphalt mixture aggregate, the research status at home and abroad of fractal study and the asphalt mixture graded theory. The key controlling sieve pore of the asphalt mixture graded in designing was studied, the great weight coefficient was given for 0.075mm,0.3mm,0.6mm,2.36mm,4.75mm in the process of optimization making the designed asphalt mixture with high stability and shear performance. Then, the example graded was designed by using optimal theory, and the pavement performance of designing-graded was tested. The results show that the asphalt mixture meet regulatory requirements and practical by using above optimal method designed. Finally the asphalt mixture was studied by fractal including aggregate shape, mixture graded and voidage fractal. The formula of asphalt mixture graded fractal was given, various graded calculation methods were unified by fractal theory, the relation of aggregate graded fractal dimension D and voidage fractal dimension were deduced.The graded optimization of asphalt mixture aggregate, the shape of asphalt mixture aggregate, aggregate graded and voidage fractal were systematic studied in this paper. The results play a certain promoting role for the asphalt mixture technology study and the development of China's asphalt pavement...