Theoretical Method of Aggregate Grading Design of Asphalt Mixture with Polyester Fiber

Applying the fractal theory,the math models of coarse and fine aggregate grading design for asphalt mixture with polyester fiber were presented.According the packing theory and through the analysis of packing characteristics of aggregate,the sieve ratio of coarse and fine aggregate for aggregate of asphalt mixture were calculated.The coarse and fine aggregates were studied respectively to determine the aggregate percentage and design gradation.With the same specific surface area for the same asphalt aggregate ratio,the formulae of coarse aggregate adjustable gradation design were investigated.Three groups of the mineral gradation of asphalt mixture were gotten from these equations.Results show that(1) the coarse aggregate is 74%,the fine aggregate is 15.2% and the filler is 10.8%;(2) for the asphalt mixture with 0.2% polyester fiber,the volume parameters of gradation No.1 and gradation No.2 cannot meet the requirements of technical specification;the volume parameters,flow value and dynamic stability of gradation No.3 all meet the requirements of technical specification.The gradation No.3 is the optimum gradation.