Research On Skid Resistance Technology Of Asphalt Pavement Based On Fractal Method

With the rapid development of highway in our country recently years, the questions of driving safety on highway have caught people's eyes progressively. Improving skid resistance performance and decreasing traffic accidents have been regarded as a hotspot-issue of asphalt pavement study.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 starts from the three levels of improving the pavement skid resistance performance - raw materials, mixture and construction, to study the fractal characteristics of aggregate shape, gradation and pavement texture ,turaing to the image processing technology, and finds out that different fractal dimensions can reflect the different details of skid resistance mixtures. Based on the fractal analysis and in-door tests, This paper brings forward the fractal evaluating model of gradations, fractal interpolation method of pavement texture and fractal evaluating index of pavement skid resistance, and discusses the variational rules of texture fractal dimension during the attenuation of skid resistance performance and mixture intensity with different fractal characteristics.Skid resistance mixtures not only need better texture characteristics after construction , and ensure slower attenuation in use than usual, but also keep the balance between skid resistance performance and others, so the gradation trend and stability is very important. After the research of attenuation rules of different coarse aggregate, gradation and NMAS (nominal maximum aggregate size) based on the home-made STSRAP (Simulating Tester for Skid Resistance of Asphalt Pavement),this paper puts forward the universal mathematic model of skid resistance attenuation ,and all the parameters of it are easy to understand and get. Furthermore, after the research on gradation trend and stability, this paper gets the selective methods of mineral gradation based on fractal dimension under different environment, and evaluation method of gradation stability based on SGC(Superpave GyratoryCompactor). To keep the balance of road-related performances , this paper points out that it's a rather good way to adopt interlocking close-graded aggregate as the gradation style of skid resistance mixture ,at the same time, puts forward the idea and the flow chart for designing this kind of mixture based on restricted uniform design method and CBR tests.The conclusions of this paper will provide an important reference for the research and application of skid resistance and corresponding mixture technology in the further.