Mechanism Of Non-linear Percolation For Low Temperature Cracking Of Asphalt Concrete Pavement

Percolation model which in essence, belongs to a branch of theory of probability, is an available tool to deal with cluster and critical phenomenon. Because of numerous micro-cracks'interaction, asphalt concrete pavement appears cracks. In mathematics, the limitless connective process of micro-cracks belongs to percolation problems. The thesis applies theory of percolation to descriibing destructive process of asphalt concrete pavement, then strikes up appropriate percolation model, and finds out percolation threshold using the method of renormalization group to determine cirtical condition of asphalt concrete pavement destory, Study show that crack generation and extension have significant non-linear percolation characteristic under low temperature load. Therefore, study on it by means of percolation theory and percolation threshold have a certain theory value.The paper first started from asphalt concrete crack mechanism of the generation and expansion,Using air temperature servo testing machine to test asphalt concrete and fiber asphalt concrete's Indirect tensile fatigue performance, detailedly observed the evolution that fracture the entire process of internal cracks cracking, expansion, brought together until the final destruction , Access to the entire process of asphalt concrete fracture in different loading conditions during the crack propagation and micro-structural changes in the photo, and used a computer image processing techniques to extract cracks.Secondly ,The cracks were on the images study, The paper used percolation theory to describe the formation and distribution of asphalt concrete cracks, established the relationship of the percolation threshold and stress,temperature, At the same time,and made quantitative analysis on the fiber asphalt concrete cracks to obtain the modified mechanism of fiber asphalt concrete using percolation threshold. Finally, with the above-mentioned physical experiment, the paper selected Visual Basic 6.0 for the developmental tools, and developed a percolation model simulation software.of low-temperature cracking of asphalt concrete .This paper got supported by the National Natural Science Foundation Project"Mechanism of non-linear percolation for Low-temperature cracking of asphalt concrete Pavement"(Grand No.50778186 ).