Estimation Model Of Optimum Asphalt Content For Drainage Asphalt Mixture Based On Fractal Theory

Because of the comparatively large void of drainage asphalt mixture, the asphalt film is prone to contact with environment, and the performance of the mixture is influenced by the factor of load of vehicles and natural environment obviously. Therefore, the drainage asphalt mixtrue needs to have the higher quality, farther more, how to determine the optimum asphalt content is very important. Currently, determine of the optimum asphalt content of drainage asphalt at home and abroad didn't have the uniform method, and the method is subjective and arbitrary. Different engineering staff made the different optimum asphalt content of optimum asphalt mixture. Providing a reasonable and reliable method appear to be very important.First of all, the thesis just begins to study from the fractal characteristics of drainage asphalt mixture, including the fractal characteristics of distribution of particle size, gradation curve, superficial area, and void fraction, and sets up the estimation model of specific surface of aggregates.Secondly, test the specific surface of the aggtegates through the laboratory experiment, and compare with the fractal theory of specific surface. Through the asphalt mixture performance test, analysis of the relationship between the asphalt content and water stable performance, high temperature stable and low temperature stable performance of draingage asphalt mixture. Basing on the analyses of the overall performance, determine the reasonable film thickness of drainage asphalt mixture. And then, calculate the specific surface of different types of stone and gradation with the fractal theory. According to the recommended film thickness pavement, determine the optimum asphalt content of drainage asphalt mixture, and compared with the method in the current codes and standards. The results show that the fractal model used to determine the optimum asphalt content is practical and reliable.