Research On The Design Method Of Asphalt Mixture With Stress Absorbing Layer Based On Road Performance

Crack reflection has been main diseases of the cement concrete pavement overlaid Asphalt Surface. How to prevent Crack Rflection, is a difficult problem ,and it troubled road engineering workers. Based on the class of disease, Road Engineering Researchers have invested considerable effort to research work on it,it mainly focused the following several aspects:(1) the research on the mechanism of Produce mechanism and mechanics analysis on Crack Rflection;(2) the research on measures of preventing crack reflection;(3) the research on the new material and new technique of preventing crack reflection. No matter what kinds of research, the final purpose is solving problems about Crack Rflection and prolonging the service life of asphalt overlay. Among the numerous measures about preventing Crack Rflection,Using asphalt mixture as stress absorbing layer is the main measure of preventing Crack Rflection about the cement concrete pavement overlaid Asphalt Surface. Now that using asphalt mixture as stress absorbing layer,it should be involved in the design of mix proportion about asphalt mixture used as stress absorbing layer. According to function characteristics of stress absorbing layer, The traditional design procedures which dominated by high-temperature stability obviously don't suit this asphalt mixture. Therefore it urgently need new the new design of mix proportion which suit asphalt mixture used as stress absorbing layer.As we all know, the design of mix proportion about asphalt mixture mainly includes gradation design and asphalt-aggregate ratio design. Therefore this paper focus on mix proportion and proceed two aspects of the work as follows:First, this paper discuss what structure characteristics of gradation is more suitable for asphalt mixture as stress absorbing layer. Considering the structure characteristics of gradation used as stress absorbing layer at present,this paper design seven gradation (including three AC5 gradation and four AC10 gradation).The gradation range determined by seven gradation includes the gradation range which used to asphalt mixture as stress absorbing layer. According to laboratory test. This paper respectively adopts volumetric parameter,high-temperature stability,crack resistance performance(Low Temperature crack and reflection crack),workable performance to verify the performance of asphalt mixture. Comprehensively considered each performance parameters. Finally, this paper select the gradation which is suitable for asphalt mixture used as stress absorbing layer.Then, Comprehensively considered volumetric parameter,high-temperature stability,crack resistance performance,workable performance, this paper Proposes the method of the design based on equilibrium of pavement performance stress absorbing layer. This method adopts the asphalt-aggregate ratio of closest compact condition as Lower Limit, adopts the asphalt-aggregate ratio of loss rate of Schellenberg Binder Drainage Test as Upper Limit, and finally determine the optimum asphalt-aggregate ratio by the optimum pavement performance.Finally,according to the method of mix proportion proposed by this paper,and through the verification of the entity engineering,it achieved good use effect.